Commodore 64 upgrades

Translates a PS/2 mouse into Commodore 1351-style analog mouse signals for the C64 and C128.

For this system (exact model): The current seller and published design explicitly support the C64. Because 1351 position data uses the SID paddle inputs, confirm that the installed SID or replacement implements the analog-input path.

Retro Computer Store listed an assembled adapter as available for USD 16 on 2026-07-30. PCBWay exposes a through-hole fabrication route with Gerbers, a bill of materials, and programming notes. The current assembled version supports PS/2 mice and PS/2-compatible serial mice but explicitly does not support a USB mouse through a passive PS/2 adapter. A working SID analog-input path is required; some replacement SID implementations omit it.

Runs a cartridge-resident suite of health, speed, alignment, sector, and command tools for 1541-family floppy drives.

For this system (exact model): The cartridge runs on a C64 and communicates with an attached 1541 or 1541-II drive. It can indicate a likely alignment problem, but the maker explicitly advises against using software alone to adjust a drive.

Protovision listed 22 units at EUR 25 with a one- to two-week shipping estimate on 2026-07-30. Jani also publishes free cartridge images for device 8 and device 9. The software alignment display is a health indicator, not a substitute for a factory analog alignment disk and oscilloscope.

Replaces a Commodore 2364 ROM with a readily available 27C64, 27C128, 27C256, or 27C512 device.

For this system (exact model): The seller specifies C64 ROM replacement. Chip-enable is tied low; program an 8 KB image at 0x0000 for 27C64, 0x2000 for 27C128, 0x6000 for 27C256, or 0xE000 for 27C512.

The product selector offered all three build levels on 2026-07-25. The included W27C512 option is blank; the buyer must provide and program an appropriate ROM image.

Tests major Commodore 64 chips, ROMs, interrupts, controls, and external ports with a cartridge and loopback plugs.

For this system (exact model): Protovision explicitly sells the kit for the Commodore 64 and states PAL and NTSC compatibility. The reviewed sequence starts with keyboard and joystick tests, then runs chip and port tests with the supplied user-port and serial-port dongles; the serial dongle must be removed for the cassette test. Follow the included manual, connect or remove every tester only with power off, and do not assume that an 8580 SID or an unlisted C64-family model receives identical coverage.

Protovision announced that 64 Doctor was back in stock on 2026-07-21. The product page listed eight units at EUR 35 with a one- to two-week shipping estimate on 2026-07-30. A detailed 2019 review identifies Tim Harris of Shareware Plus as the licensed manufacturer and demonstrates the test sequence, but it does not establish equivalent sound-test behavior for an 8580 or replacement SID, the SX-64, or a C128 in C64 mode.

Safely translates Sega, NES, SNES, or legacy analog PC controllers for Commodore, Amiga, and Atari-style control ports.

For this system (exact model): Plugs into either control port. Choose the color-coded interface for the intended controller and use the required Nintendo or DB15 adapter. Switch the computer off before connecting hardware.

The official page still displayed order instructions and prices from USD 14.95 for the chipless protection version through USD 36.95 for a combo interface with an adapter on 2026-07-30. However, its prominent post-COVID shipping notice and 2021 copyright are stale, and it says only that most items remain orderable. Contact 64HDD for exact version, stock, price, and postage before sending payment. SNES-to-JPX and PCanalog are companion adapters and remain in this product family.

Adds wired 10 Mbit Ethernet and RR-Net-compatible networking to C64-family computers, with an optional multi-ROM socket.

For this system (exact model): The maker explicitly supports C64 and C64C systems. Select compatible RR-Net, NET64, TFE, or 64NIC+ software and configure IO1 or IO2, register order, and the 16-byte base address to avoid conflicts with other cartridge hardware.

The current RETRO Innovations store exposed the 64NIC+ category and a Choose Options purchase path on 2026-07-30. The product comes in four case and ROM-selector configurations. Network software, an Ethernet cable, and a 10 Mbit-capable network connection are required separately.

Adds stereo 8-bit audio sampling hardware to a Commodore 64.

For this system (exact model): The seller explicitly names the Commodore 64. No published manual establishes connector placement, input levels, sample rates, channel handling, or compatible software, so confirm those details before purchase or use.

The seller page was last updated on 2025-01-01 and then claimed stock by email, but Shareware Plus exposes no conventional store or current checkout path. HR-060 closed with direction to stop pursuing that stale sale claim, so availability remains unknown. The seller also says it does not know which software works and that the project did not progress beyond the hardware release.

Current composite and S-Video cable options for compatible Commodore computers, with a five-pin composite branch that also serves selected Atari systems.

For this system (exact model): The five-pin composite cable works with all C64 versions. Later machines with the eight-pin A/V socket can instead use the S-Video and composite cable. Early Assy 326298 systems do not supply the separate chroma signal needed by the eight-pin S-Video branch. Optional stereo requires a suitable second audio source; otherwise use the mono arrangement.

The two five-pin products exposed Add to cart controls, while the eight-pin product exposed current priced options on 2026-07-30. The five-pin cable and adapter carry composite video and two audio connectors; those connectors do not create an independent stereo source in a stock mono computer. The eight-pin S-Video branch requires a host that supplies separate luma and chroma. Its stereo option requires a compatible second audio source on the designated extra pin. Match the connector, resistor, audio wiring, display input, and regional video standard before ordering.

A current 1.5-meter five-pin DIN to SCART cable for several Commodore computer families.

For this system (exact model): The seller explicitly lists the C64 and C64C. This five-pin cable carries composite video rather than S-Video and remains suitable for an early five-pin C64.

The product page exposed a current Add to Cart path on 2026-07-30. The cable is 1.5 meters long and terminates in a five-pin DIN plug, so it does not carry the separate luma and chroma signals used for S-Video. Confirm that the intended display accepts composite video through SCART and that its regional video standard matches the computer.

Replaces one SID socket with two or three emulated SIDs, or combines SID emulation with SFX Sound Expander-compatible FM synthesis.

For this system (exact model): The developer explicitly supports all C64 board revisions. A short-cable version is intended for systems that already provide two SID sockets, while the 30 cm cable version connects the required signals directly without a separate stereo adapter. Configure the emulated chip types, addresses, and audio routing for the installed board.

The official store showed four ARM2SID variants in stock on 2026-07-28, priced from EUR 53 to EUR 58. Choose the cable, optional second socket, and host-specific version carefully. Additional SID and FM modes require the documented chip-select and audio connections; the optional second socket does not carry EXT IN.

Microcontroller-based plug-in replacement for a C64 or C128 6581 or 8580 SID with software configuration, updateable firmware, and analog control inputs.

For this system (exact model): The developer documents ARMSID as a plug-and-play C64 replacement for either the 6581 or 8580, with no computer modification required. It also emulates the SID POTX and POTY analog inputs used by paddles and mice.

The official Retrocomp product page showed more than 10 ARMSID v1f units in stock at EUR 34 on 2026-07-28.

Breaks compatible Atari and Commodore monitor-port signals out to S-video, composite video, and bridged mono audio connectors.

For this system (exact model): The seller explicitly lists the Commodore 64 as composite-only with this breakout. It does not advertise an S-video path for the C64.

The current product data and catalog reported the assembled breakout in stock on 2026-07-27. Cables and any required computer modification are not documented as included.

Small C64 prototyping boards for the cartridge port, user port, or a combined dual-port project.

For this system (exact model): The page explicitly identifies all three arrangements as Commodore 64 prototyping PCBs. It does not claim C128, SX-64, or VIC-20 operation. Select the correct cartridge-port, user-port, or dual-port design, verify orientation and connector clearance, and connect or remove it only while the computer is powered off.

The email-order page was last updated on 2025-01-01 and then said any combination was available, but it publishes no price, checkout path, schematic, pin map, bill of materials, design files, or protection details. Confirm present stock, the exact board variant, connector and header parts, case fit, and documentation before ordering. Treat every exposed power and signal line as unprotected unless the seller supplies contrary electrical documentation.

Uses one microSD cartridge and interchangeable adapters to load software and provide selected storage, cartridge, memory, and diagnostic functions on many vintage computers.

For this system (exact model): Use the C64/128 adapter. The cartridge reads and writes supported D64, D71, D81, and D8B images and handles several cartridge, program, snapshot, image, and music formats. Assy 326298 needs the maker's reset fix.

The current store listed the assembled BackBit Pro for $129 on 2026-07-27 with one assembled adapter choice included. A microSD card is not included. Additional adapters are sold separately and require through-hole soldering. Firmware updates use the microSD card. An original C64 Assy 326298 needs the documented reset fix, and the SX-64 needs the straight C64/128 adapter.

VIC-II socket video coprocessor that adds programmable display effects, 512 KB of local memory, and integrated video cleanup to a C64.

For this system (exact model): The maker documents 6567R56A, 6567R8, 6569, 6572, 8562, and 8565 VIC-II chips and reports tests on Assy 250407, 250425, 250466, and 250469 boards plus C64 Reloaded MK2. Installation normally uses the VIC-II socket, but case clearance can require soldering on some narrow C64C boards.

The official project page remains online, but its Buy now area exposed no price, stock state, or working order destination on 2026-07-30. The last seller route found during this pass returned 404, and human review found no replacement seller, so confirm a current source before planning a purchase. BeamRacer also includes Lumafix Pro, software control of the HMOS-II gray-dot effect, a direct VideoMod connection, USB-C firmware updates, and the optional VBASIC development environment. Some narrow C64C boards may require a nearby capacitor to be resoldered for case clearance.

Cartridge-port prototyping board with a mini breadboard and jumper leads for building C64 circuits.

For this system (exact model): The product title and description explicitly name the C64. The surrounding store category also names the C128, but that category placement is not model-specific evidence, so no C128 relationship is claimed. Verify orientation and every breadboard connection before applying power, and connect or remove the board only with the computer off.

Poly.play listed SKU PP0057 at EUR 17 including German VAT but marked it out of stock on 2026-07-30. The page publishes no schematic, pin map, design files, license, buffering, isolation, fusing, current limit, or power-handling specification. Confirm a restock and treat every computer signal and power line as unprotected.

Provides a weighted, tabletop arcade joystick for Atari 7800 and Atari VCS-style computer control ports.

For this system (exact model): The maker archive explicitly lists the C64 and describes compatibility with systems that accept an Atari VCS-style controller. The Atari 7800 second-button circuit is a console-specific feature; do not assume it supplies an independent second C64 fire input.

BX Foundry's joystick production run concluded in mid-2019. The maker archive remains available, but it provides no current order route or public construction files. Search the used market for an original unit.

Historical C64 user-port board providing 32 general-purpose input and output connections.

For this system (exact model): The demonstration and GPIOTracker repository explicitly identify the Commodore 64 version and Dorktronic 32-pin board. They do not establish C128, VIC-20, PET, or other user-port compatibility. Verify connector orientation, supply selection, signal voltage, load current, and grounding for the attached circuit, and do not connect or remove user-port hardware while powered.

A February 2021 demonstration points to former eBay item 333905309830, but the exact listing failed two Tavily extractions after the required 60-second retry and is logged as WF-065. No current hardware seller, board design package, manual, pin map, electrical limit, protection circuit, or hardware license was verified. Treat the board as a used-market find. The demonstrated LED bank uses 1K resistors and leaves VCC disconnected; that example is not a general electrical specification.

Uses a PS/2 keyboard on supported Commodore computers or converts their original keyboards and optional joysticks for a PS/2-equipped host.

For this system (exact model): The maker documents C64 and C64C configurations. The board can sit between the motherboard and original keyboard so the built-in keyboard remains usable. Remove the keyed header pin and match pin 1 exactly as directed.

The RETRO Innovations store exposed a configuration selector and Add to Cart path on 2026-07-30, with the bare PCB listed at USD 6 and configured kits priced separately. Kits and assembled units are made after ordering and normally take four to five weeks. The maker explicitly treats C=Key as a project rather than a fully supported product because its firmware is not extensively tested or easily upgraded; an AVR programmer is strongly recommended. Use a true PS/2 keyboard because passive USB adapters may not work.

Adds a buffered external C128D keyboard connection to a Commodore 64 while retaining the original keyboard.

For this system (exact model): The project was built and verified for the C64. It requires opening the case, inserting the booster between the motherboard and original keyboard, and wiring a female DB25 for the C128D keyboard. Double-check connector views and pin orientation before power-up.

The surviving workshop page provides a schematic, pin map, parts list, and verified build instructions, but no PCB files, kit, or explicit reuse license. It warns that a direct long-cable connection can overload and destroy the C64 CIA. The buffered design was intended for cables as long as 10 meters, although its troubleshooting section still recommends shortening a troublesome cable to about one meter.

Lets a detachable Commodore 128D keyboard serve as the keyboard for a Commodore 64.

For this system (exact model): Protovision explicitly sells this for using a C128D keyboard with a C64. The public listing does not distinguish breadbin and C64C cases or long- and short-board revisions, and it does not document installation, cable length, line buffering, or the C128-only keys. Confirm those details before opening the computer or ordering the cable option.

Protovision listed 17 units from EUR 15 with a one- to two-week shipping estimate on 2026-07-30. Its news page says versions are available with or without an extension cable. Human review found no visible active components or additional documentation, but that does not prove the board is unbuffered. Ask the seller about buffering and safe cable length before using a long cable, and connect or disconnect the adapter only while the computer is powered off.

Tested 64K-by-1 4164 DRAM chips for repairing Commodore 64 motherboards that use the eight-chip, 16-pin memory layout.

For this system (exact model): Use only on a C64 motherboard populated with eight compatible 16-pin 4164 or 4264 DRAMs. Retroleum identifies U9 through U12 and U21 through U24 on the supported breadbin layout and excludes Assy 250466 plus two-chip C64C layouts. Power off and unplug the computer before service. Safely desolder any soldered devices and fit suitable sockets; do not treat piggyback testing as a conclusive diagnosis.

Both exact product routes were present on 2026-07-30, but Tavily did not expose an unambiguous current cart or stock control on the ToTs RETRO page, and Retroleum was temporarily closed until approximately the beginning of August 2026. Confirm stock before ordering. Match the installed memory organization and motherboard rather than relying on case style: Retroleum explicitly excludes Assy 250466 and C64C boards that use two 41464 or 4464 devices.

Boots before the normal KERNAL to diagnose RAM and ROM faults on a Commodore 64 that cannot reach its startup screen.

For this system (exact model): Current sellers explicitly support the C64 and C64C. Insert and remove the cartridge only with power off, then allow up to 60 seconds for the initial result. Border flashes identify likely failed RAM circuits within the test's lowest-4-KB scope; use a fuller diagnostic after the machine can boot.

Retro Rewind listed its cartridge in stock at CAD 22 on 2026-07-30. TFW8b documented a compatible alternative for C64, C64C, SX-64, and C128 in 64 mode, but that listing was out of stock. Wait up to 60 seconds for a result. The original 781220 RAM routine covers only the lowest 4 KB, and the cartridge does not test the chips and I/O covered by a harness kit.

Generates configurable YPbPr or RGB from VIC-II bus activity with an FPGA while retaining improved composite and S-Video output.

For this system (exact model): The hardware supports PAL and NTSC, longboards and shortboards, and 5 V or 12 V VIC-II variants. Installation removes the RF modulator and places an interposer under the VIC-II; some boards need extra socket height or relocated passives. The early 6567R56A needs current firmware and a documented JTAG-header ground jumper. The seller explicitly says this C64 kit is not compatible with the C128.

VideoGamePerfection's EUR 60.00 kit was out of stock on 2026-07-27, but the complete open design remains buildable and upstream firmware 2.12 was released on 2026-07-03. This is a substantial soldering installation, and the original RF output is removed.

Open, through-hole RF-modulator replacement with adjustable C64 luma and chroma output levels.

For this system (exact model): The project explicitly supports Assy 250407, 250425, 250466, and 250469 with NTSC or PAL VIC-II chips. Assy 326298-01 with the five-pin A/V port is incompatible. Use all jumpers in the documented longboard position for 250407, 250425, or 250466 and in the shortboard position for 250469.

The repository supplies KiCad sources, Gerbers, a schematic, a BOM, and assembly and adjustment instructions. Components were estimated at about $12 when documented, excluding PCBs and shipping. Building the board requires through-hole assembly; installing it requires safely desoldering the original RF can and selecting the correct jumper configuration. Using the shortboard setting on a longboard can feed the wrong voltage and damage the VIC-II.

Adds an inexpensive battery-backed real-time clock to a Commodore 64 through the user or cassette port.

For this system (exact model): Connect a DS3231 module to user-port ground, +5 V, SDA, and SCL using either PB0/PB1 or PB2/PB3, or use the documented cassette-port wiring. The PB2/PB3 choice was tested alongside a user-port RS-232 Wi-Fi modem. C64 OS has an I2C RTC driver, while the project package includes native utilities and C64 GEOS software.

The current project page provides version 1.0 software and exact wiring for three C64 connection choices. Gregory Nacu's i2c6502 source independently documents the C64 user-port PB2/PB3 implementation and DS3231 example under the MIT license. A generic RTC module, connector or pass-through board, wire, and battery are separate. Many inexpensive modules include a charging circuit intended for a rechargeable cell; follow the project's component-removal instructions before substituting a CR2032 or CR1225 primary cell. The Timo Voutilainen package does not state a hardware fabrication or software license.

Provides an open build for selecting either Commodore 64 control port from one Atari-style joystick, with optional second-fire and autofire circuits.

For this system (exact model): The open design is specifically for the C64 and plugs into both control ports. It is documented for common Atari-style joysticks and optional Sega Master System-style second-fire wiring, not Genesis or Mega Drive controllers.

The repository supplies KiCad files, Gerbers, a schematic, bill of materials, and assembly guidance. Inspect the completed board for solder bridges and support it while pressing its buttons. Never move jumpers while powered or map two physical inputs to the same function. Do not connect a Sega Genesis or Mega Drive controller; the maker warns that it may damage the C64 and directs those controllers to the separate Mega Switcher.

Swaps both Commodore 64 control ports and adds a PS/2 mouse input compatible with 1351-aware software.

For this system (exact model): The seller explicitly documents the C64, both control-port mappings, paddle-controller operation, and use of a PC PS/2 mouse with Commodore 1351-aware software. No C128, VIC-20, Amiga, or Atari relationship is inferred from the connector shape.

Sordan exposed a current Buy now control and says stocked items are ready to ship. The package includes a white 3D-printed case. The seller explicitly supports paddle controllers and says the circuit protects against static while controllers are changed, but does not publish a schematic, supported PS/2 protocol variants, USB-mouse compatibility, connector pinout, or hot-plug procedure.

Rebuilds a Commodore 64 around a preassembled replacement motherboard with automatic chip configuration, static RAM, flash ROM, and dual-SID support.

For this system (exact model): This replaces the original motherboard in a C64 case rather than upgrading the existing board. It automatically detects supported installed chips and configures their clocks, voltages, and SID filters. Confirm the required donor or replacement chips, compatible case and keyboard, and 12 V supply before ordering.

Individual Computers marked the board available for immediate delivery on 2026-07-27. It is not a complete computer: the key CPU, port, sound, and video chips are not included. The product page still uses some preproduction or older photographs, so physical appearance can differ.

Replaces the paired 41464 or 4464 DRAMs on later two-chip C64 boards with a modern SRAM module.

For this system (exact model): Use only on a two-DRAM motherboard that the chosen module explicitly supports. Assy 250469 uses U10 and U11 and is the best-supported target. Jaystonian also lists 250466 but reports only about 80 percent reliable results; do not generalize this module to eight-DRAM C64 boards.

Jaystonian showed nine assembled modules in stock at USD 14.99 on 2026-07-29, and Retro Lemon exposed a GBP 17.50 product page without an out-of-stock marker. Assy 250469 is the well-tested target. Jaystonian reports mixed results on 250466, and the open project's author had only tested 250469. Original soldered DRAMs require careful desoldering and sockets before this becomes a plug-in repair.

Passive one-to-three Commodore 64 user-port expander with an onboard reset button.

For this system (exact model): The current listing identifies the Commodore 64 product line, and the reviewed hardware was used on a C64. Attached devices share the same user-port signals and must be safe to operate together.

The Arcadia by Eye-Box listing was out of stock on 2026-07-27. A reviewed Shareware Plus unit exposed three connectors. The right-hand position can obstruct the cassette port, and the passive board has no per-slot disable controls. Connect or remove peripherals only with power off.

Adds a Yamaha V9958 or V9938 video processor, 128 KB of dedicated VRAM, RGB output, sprites, and enhanced graphics modes through the expansion port.

For this system (exact model): The card plugs into the expansion port and provides amplified analog RGB plus TTL sync for a compatible 1084 monitor or SCART display. Its graphics memory is accessed through VDP ports rather than as normal C64 RAM. Select the correct I/O address and cartridge image configuration before programming the GAL and ROM.

The project publishes the final 1.0 PCB, schematic, Gerbers, GAL files, documentation, and demonstration software, but no current assembled seller was verified. A build requires a V9958 or modified V9938 configuration, two compatible DRAM devices for 128 KB of interleaved VRAM, programmable logic, an EPROM or EEPROM if desired, and substantial surface-mount assembly.

Open RF-modulator replacement that improves the C64's original luma, chroma, and composite video signals.

For this system (exact model): The seller specifies both longboard and shortboard C64 versions. Confirm the board revision and pin orientation, fully disconnect power, and use appropriate desoldering and soldering equipment before removing the RF modulator.

Retro Electronics listed one board in stock on 2026-07-25. Installation is an irreversible soldering job that removes the original RF modulator, adds two headers, and solders a ground wire.

Buildable NodeMCU Wi-Fi modem for the Commodore 64 user port with voltage level shifting and status indicators.

For this system (exact model): The maker designed the project for the Commodore 64 user port. Builders must match the PCB revision to the NodeMCU width and follow the linked firmware and wiring instructions.

The complete project remains downloadable. Retro-Updates listed an assembled revision-2 version for the C64 and C128, but it was out of stock on 2026-07-30. Revision 1 fits only the smaller WeMos NodeMCU v3 form factor; revision 2 supports both common board widths.

Adds the loopback modules needed for complete 586220 C64 or 785260 C128 port and interface diagnostics.

For this system (exact model): Use a correctly configured 586220-family cartridge. Older revision-0 harnesses need separate passes with and without the keyboard dongle for a valid control-port test; revision 1 and later switch that feedback automatically. A BAD result identifies a possible fault path, not necessarily a dead chip. Never attach, remove, or rearrange any harness part while powered.

Current routes on 2026-07-30 included Retro-Updates' EUR 17.95 harness with an Add to Cart path, Retro Rewind's CAD 75 harness with a one- to two-week lead time, Retro Rewind's separate CAD 22 C128 keyboard dongle in stock, and AMI64's GBP 49 complete eight-ROM kit. Retro Electronics had one complete kit on 2026-07-25 but documented only one tested PAL C64 board revision. Confirm the exact harness revision, cartridge, keyboard dongle, cable lengths, model settings, and included manuals before ordering. Human review found no evidence that the current retail dongle solves the documented C128DCR keyboard-jack power conflict.

Packages 586220, 785260, and related service ROMs as current single-ROM and switchable multi-ROM diagnostic cartridges.

For this system (exact model): All indexed C64 variants explicitly support the C64, and current AMI64 and Retro Rewind variants also name the C64C. Retro Rewind's current single-ROM cartridge uses 586220++ with improved KERNAL detection. Select the intended ROM and cartridge mode before power-up. The 781220 test checks only the lowest 4 KB of RAM; 586220 reports false interface failures without the matching harness. Read the manual before treating a BAD result as a failed chip.

Current choices on 2026-07-30 included Retro Rewind's in-stock CAD 22 C64 586220++ and C128 785260 cartridges, its CAD 40 four-ROM C64 cartridge with a two- to three-day lead time, AMI64's GBP 19 eight-ROM C64 cartridge with an approximately seven-day lead time, ogHugo's USD 26.99 before-tax two-sided C64 cartridge with an Add to Cart path, Retro-Updates' EUR 17.99 two-sided C64 cartridge, and C64iSTANBUL's orderable two-ROM PCB with current fabrication files. DIY8BIT's USD 22.95 781220/586220 cartridge was unavailable while its Etsy shop was on break. Retro Rewind's older Dual Diag route now displays the store's not-found page. ROM sets and model support differ by variant; a full port test requires a separately bought or built harness.

A compact universal-input replacement supply for Commodore 1541-II and 1581 floppy drives.

For this system (bus/interface): This powers a 1541-II or 1581 peripheral rather than the C64 itself. Verify the drive's four-pin power connector and required ratings before use.

Retro Lemon exposed a live GBP 27.50 listing with free delivery on 2026-07-30, but the extracted page did not expose an unambiguous stock or Add to Cart state. Confirm availability and delivery region before ordering. The page does not publish over-voltage protection, fusing, isolation, connector pinout, or serviceability details.

Adds Hayes-style Wi-Fi modem access and ZiModem networking functions to a Commodore 64 through the user port.

For this system (exact model): The maker explicitly sells the card for the Commodore 64 and states operation up to 9600 baud. Early revision-04 boards can fail completely or at 9600 baud unless the documented C64-RTS pull-up resistor is added; newer boards include the fix.

The maker page exposed current eBay and Amiga on the Lake purchase routes on 2026-07-30. The buyer's-guide card and cased listings are one hardware family; confirm the enclosure, board revision, and installed firmware with the seller before ordering.

Swaps a Commodore computer's two control ports while preserving both digital joystick and analog mouse or paddle signals.

For this system (exact model): The designer documents C64 operation. The board occupies both control ports, switches digital and analog lines, and can change the active mapping while the computer is running.

The surviving AmiBay production runs are closed sales archives. COREi64's former product route is currently replaced by a store-wide notice saying the shop will return in Fall 2026, so no current C8D order path is verified. The original C8D maker site also failed Tavily extraction twice after the required retry and is recorded as WF-050.

Single-position angled C64 cartridge adapter with power switching, reset, an activity LED, and support feet.

For this system (exact model): The listing explicitly identifies the Commodore 64. The adapter turns one cartridge upward and adds switching and reset controls.

The black, red, and white variants were all out of stock on 2026-07-27. Color variants are one hardware family. This adds convenience rather than another simultaneous cartridge position; power off the computer before connecting or removing either board.

Adds SD-card PRG and TAP loading, a fast loader, Wi-Fi file transfer, and cross-development tools through the cassette port of several Commodore 8-bit families.

For this system (exact model): The maker reports successful C64 testing. Turbo Chameleon bypasses the cassette signals and is explicitly incompatible. Disable JiffyDOS, and do not combine Cassiopei with another cassette-port device except a datasette as documented.

The maker states that Cassiopei v2.0 is not available. The hardware is described as functionally complete, while firmware, software, manuals, and downloadable updates remain published.

Current hand-built replacement for the MOS 8701 clock generator in later PAL and NTSC Commodore 64 boards.

For this system (exact model): The seller explicitly supports later PAL and NTSC C64 models. It does not enumerate motherboard assemblies, so inspect the actual board for a socketed MOS 8701 rather than relying on the case style. C128 compatibility is not claimed.

CBMretro exposed an in-stock add-to-cart path on 2026-07-30. The page says only that the board is for later C64 models and does not name assembly numbers or the C128. Confirm that the computer actually uses a socketed MOS 8701 and verify orientation before ordering or installation.

Adds two joystick ports to a compatible Commodore user port for four-player games that support the CGA adapter protocol.

For this system (exact model): Connects to the user port and supplies two additional digital joystick sockets. Games must explicitly support the CGA or Protovision four-player protocol. The extra ports provide directions, fire, and 5 V, but not the full set of analog paddle or light-pen signals found on a normal C64 control port.

Protovision showed 17 individual Computers adapters in stock at EUR 25 with a one- to two-week shipping estimate on 2026-07-30. CBMretro also exposed an add-to-cart route for Pasi Lassila's enhanced Neat design at EUR 26.90, and ZGCS showed two assembled compatible boards at USD 22 on Tindie. Install or remove the adapter only with power off and observe connector orientation. Do not connect it to a Plus/4: individual Computers warns that doing so risks damage. The PET 2001 user ports lack the required power connection, and the maker discourages modifying a historic machine to add it.

Adds a battery-backed DS3231 clock, external LED time display, date display, and timer to a Commodore 64.

For this system (exact model): The assembled clock connects directly to the C64 user port. It is documented for original CIA chips; the maker reports problems when modern J-CIA replacements are installed. Use the maker-recommended version 0.2 software for computer-readable date and time.

The Tindie page listed Clockwork64 at USD 38 but had ordering paused while the seller takes a break through July 31, 2026. It calls this the final batch before retirement, so confirm that an order can still be placed after the seller returns. A CR2032 is included. The maker reports compatibility problems with modern J-CIA replacement chips and directs buyers to version 0.2 of Timo Voutilainen's RTC software.

Licensed, made-to-order recreation of the CMD hard drive with BlueSCSI v2 and externally accessible SD storage.

For this system (exact model): The seller explicitly lists the C64 and C64C. Supply an IEC serial cable and a compatible external power supply. The default device ID is 12.

ToTs RETRO exposed an Add to Cart path at USD 899.99 on 2026-07-27. Each drive is made to order with an advertised lead time of up to one week. Supply an IEC serial cable and a compatible 1581 or 1541-II power supply; neither is included. The seller has not tested simultaneous tape-drive use.

Current switched cable variants for using the C128's 40-column analog video and 80-column RGBI output with one display setup.

For this system (exact model): The seller explicitly permits the 40-column branch on a C64 with the later eight-pin 262-degree DIN A/V connector. The page excludes the early silver-label connector. Only the composite or premium S-Video path applies; a C64 has no C128 80-column RGBI output.

Both Tindie pages exposed current prices and ordering controls on 2026-07-30; the premium version explicitly reported three units left. Shipping depends on the selected destination, and no rate was shown during extraction. The seller documents a shielded cable, an onboard micro PCB, and an operating LED. No scan conversion is documented, so confirm that the intended display accepts the cable's original-timing composite, S-Video, and SCART RGB signals.

External displays for checking the 5 VDC and 9 VAC outputs of Commodore power supplies, with the MkII adding current measurement under load.

For this system (exact model): The review demonstrates the monitor with C64 supplies and documents user-port, unloaded-PSU, and inline loaded-monitoring modes. The MkII reset button works only in user-port mode, while current measurement requires the supplied cable between the supply and computer. Verify cable orientation and ratings before leaving it inline.

The exact review was published in March 2020 and a February 2023 comment says the seller was still making the monitors. The review describes an unofficial Commodore-styled product made by an unnamed Australian builder, not a verified Commodore-manufactured accessory. A current-looking Pocket 1501 eBay route failed exact Tavily extraction and failed again after the required 60-second retry under WF-068, so its maker, stock, price, package, and relationship to MkI and MkII remain unverified. The separate FDD II drive-supply monitor is not folded into this host-monitor family. This device displays readings; no automatic cutoff, regulation, over-voltage clamp, fuse, or other protective action was verified.

6522 VIA interposer that changes a Commodore 1541 drive between device IDs 8 through 11 without cutting its original jumpers.

For this system (bus/interface): The switcher modifies a separate 1541 drive, not the C64. Match the documented 6522 position to the drive board and align both sockets correctly.

TheRetroChannel listed five boards in stock on Lectronz on 2026-07-27. External wiring and DIP switches are not included. A drive with a soldered 6522 first needs the chip desoldered and a socket installed; an external switch may require case cutting.

Connects a standard 3.5-inch PC floppy mechanism to a Commodore 1581 disk drive.

For this system (bus/interface): The seller lists this as a C64 accessory for a Commodore 1581 drive. It does not replace the complete 1581: supply a suitable standard 3.5-inch PC floppy mechanism and the required cables.

Retro Electronics listed two adapters in stock on 2026-07-25. Only the adapter is supplied; cables and the replacement floppy mechanism are not included.

Assembled replica controller board for building a Commodore 1581-compatible 3.5-inch disk drive.

For this system (exact model): The seller tested the board on a C64 with both a physical floppy mechanism and a Gotek. A modern PC 3.5-inch drive must be modified and connected through a separate 1581 adapter; the board also needs a drive, case, cables, and suitable power supply.

Retro Electronics listed the fully assembled and tested board out of stock on 2026-07-25. Only the controller PCB is supplied.

Upgrades an original Commodore 1764 REU from 256 KB to 512 KB and supplies parts that can also repair or expand other 17xx REUs.

For this system (exact model): The seller explicitly names the C64 and C64C as hosts for the 1764 REU. The computer remains dependent on a working original REU and an adequate power supply.

The current Shopify product page exposed a priced checkout product on 2026-07-29. This is a component kit for an original REU, not a complete memory cartridge. The page does not provide a complete board-revision-specific installation procedure; use appropriate Commodore service information, ESD precautions, and an experienced installer.

Replaces a missing or failed Commodore power indicator with a prewired round or rectangular LED assembly selected for the case and motherboard layout.

For this system (exact model): A breadbin case uses a round 5 mm LED and grommet, while a C64C case uses a rectangular LED. Short C64C leads suit common later C64C boards with the header near the top-left; use a long lead when installing an older board, including a 250466-style layout, in a C64C case. Power off and unplug the computer before opening it, and verify two-pin connector polarity.

AMI64 listed its red breadbin and C64C choices for GBP 4.95 on 2026-07-30. Poly.play also maintained separate current short and long C64C and breadbin product routes. Retroleum listed original and new round and rectangular assemblies but was temporarily closed until approximately the beginning of August 2026. Color is cosmetic, but LED shape and cable length are not: choose them for the exact case and board position. Confirm current stock before ordering.

A period automatic RF switch box currently offered as new old stock for Commodore 64 and 128 systems.

For this system (exact model): Poly.play files the original switch box under Commodore 64/128 hardware. Use requires the computer's RF output and a region-compatible analog tuner path.

Poly.play listed original part number 252652-01 as immediately available in original packaging on 2026-07-30. This is finite new old stock, not a modern video converter. It requires a television or demodulator with a compatible analog RF input, connector, channel, and regional broadcast standard; the seller page does not publish those electrical details.

Connects one CS/A65 expansion card to a Commodore 64 expansion port or beneath a PET's socketed 6502.

For this system (exact model): Revision 1.0C is explicitly for the C64 and is marked okay. It plugs into the expansion port and accepts one CS/A card. The author explicitly excludes the C128; verify address jumpers, software, connector clearance, and power for the selected CS/A board.

The C64 revision 1.0C is marked okay and publishes Eagle files, but it works only with the C64, not the C128, and a fitted CS/A card can conflict with long video or IEC plugs. For PETs, revision 1.1A was tested only in a CBM 8296 and had power and clearance problems. Later 1.2A and 1.2B layouts add 3.3 V power and more mounting options but are explicitly untested. A working 8296 Ethernet stack is documented. usb65 later lists PET plus adapter plus NetUSB 1.x as tested, although the older NetUSB page says its single PET-adapter test was not fully working and suspected a supply problem. Treat that USB path as experimental. No current assembled seller was verified.

Current C64 and C128 user- and cartridge-port boards that expose labeled pins for prototyping and hardware development.

For this system (exact model): Both current Commodore4ever variants explicitly name the C64. The user-port board exposes labeled pins for test and microcontroller work. The expansion-board title explicitly names the cartridge or expansion port, although its copied user-port paragraph does not document the exact header mapping. Follow the board orientation and seller safety guidance, remove power before installation or removal, and assume exposed pins are passive and unprotected.

Commodore4ever exposes current priced product variants for separate C64/128 user-port and cartridge or expansion-port boards. The user-port page documents its labeled male header and intended test uses. The expansion-board title and board label say EPB and cartridge or expansion port, but its body mistakenly describes access to the User Port and does not enumerate its signals. Human inspection found these guide breakouts to be basic passive pin extenders with no visible active components. No buffering, isolation, fusing, or current limiting is documented; exposed computer pins should not be treated as protected. Syzygy's C64 user-port version is retired and needs its selected header rows soldered.

Period cartridge interfaces connect a C64 or VIC-20 to PET-style parallel disk drives, printers, modems, and other IEEE-488 equipment.

For this system (exact model): The archive identifies a dedicated C64 IEEE-488 interface with preserved schematic and ROM. The original software disables serial IEC and uses part of the $C000 address area.

These are original period interfaces to find used or reconstruct from archives, not current products. Match the cartridge to the exact computer and verify its ROM. The original C64 software occupies part of the $C000 area and disables serial IEC; Andre Fachat's separate modified C64 KERNAL can retain both buses, but it is not part of the cartridge.

Breaks a compatible Commodore A/V port out to S-Video, composite video, stereo SID audio, and a stereo mini-jack.

For this system (exact model): Connects to the C64 A/V port and exposes composite, S-Video, two RCA audio outputs, and a stereo mini-jack. Assy 326298 machines cannot supply S-Video through their five-pin socket. Set the chroma, mono or stereo, second-channel, and noise-filter jumpers for the exact computer and SID arrangement.

The maker showed four V2 units in stock with a working cart path on 2026-07-29. Early C64 Assy 326298 machines use a five-pin video socket: composite output works, but S-Video does not. The optional SID-ground noise-reduction jumper must not be enabled on an Ultimate 64 board.

Adds experimental USB host and device hardware through Commodore user and cassette ports.

For this system (exact model): The board provides jumper settings for the C64, but the author says revision 1.0A had so far been tested only with a PET. Treat C64 use as an unverified design target and check user-port, cassette-port, power, and driver requirements.

Revision 1.0A is marked okay but was tested only on a PET. Revision 1.1A adds separately regulated, switchable USB host power but is explicitly untested. The interface uses both the user port and cassette port; PET ROM interrupt handling can switch cassette-motor-controlled USB power off unless software works around it. usb65 describes preliminary keyboard mapping, limited features, broken MAX3421 hub enumeration, and only partly working device mode. USB mass storage and networking are future plans, not supported features.

Host-specific passive A/V adapters for the VIC-20, C128 family, Plus/4, and Ultimate64 replacement mainboards.

For this system (exact model): This relationship applies only after replacing the original C64 motherboard with a 1541 Ultimate Ultimate64 or Ultimate64 Elite board. Use the dedicated U64 variant, which provides composite video, S-Video, and separate left and right audio. Its pinout is explicitly different from an original C64, and no compatibility with the newer Commodore 64 Ultimate is established.

Commodore4ever exposed active Add to cart controls for all four variants on 2026-07-30. The Ultimate64 board uses a different A/V pinout from an original C64; do not use that adapter on a stock C64 or assume compatibility with the newer Commodore 64 Ultimate. The C128 variant handles the 40-column analog output, not the separate 80-column RGBI port.

Protected switched-mode replacement supplies for the C64 and round-connector VIC-20CR, with separate adapters for the C128 and Plus/4.

For this system (exact model): The three current ATOM variants connect directly through the C64 seven-pin power socket and publish 5 VDC at 3 A plus 9 VAC at 1 A. Match the selected supply to the local mains input and verify that it has returned to stock.

On 2026-07-30, Commodore4ever listed the original ATOM and ATOM v2.5 at USD 59.99 and ATOM RETRO at USD 69.99; all three were sold out. The official Plus/4 adapter was also sold out at USD 24.99. A separate live 90-degree adapter page listed a 64-to-128 option at USD 14.99, but did not expose unambiguous variant stock or identify every supported ATOM revision. The original ATOM page lists separate North American 120 VAC and European 230 VAC configurations, ATOM v2.5 lists only the North American input, and ATOM RETRO says its European version is currently unavailable. Surviving pages provide too little detail to establish exact specifications or final availability for the older PS-64 with LED and PS-64/128. Do not assume that ATOM specifications apply to those predecessor models.

User-port Wi-Fi modem for reaching Telnet BBS services from several Commodore 8-bit computers.

For this system (exact model): The seller documents C64 user-port operation at up to 9600 baud. Install the modem chip-side up with the computer powered off.

The seller's collection listed the modem as sold out on 2026-07-30. An optional case is an accessory for the same modem family. The product page does not provide a public firmware or complete hardware build package.

Provides a new-production Competition Pro-style microswitch joystick with a nine-pin connector for classic computers.

For this system (exact model): The current seller explicitly lists the C64 and the original nine-pin D-sub interface. The joystick provides digital directions and fire controls; it is not a paddle, mouse, or analog controller.

AMIGAstore listed the Competition Pro Retro at EUR 32.75 but marked it out of stock with restock T.B.A. on 2026-07-30. The store still offers a stock-notification route. Do not substitute the currently available Competition Pro Extra without an adapter: that model uses USB-A for modern hosts rather than a classic nine-pin joystick plug.

Builds a Commodore 1581-compatible IEC disk drive from CS/A65 processor and floppy-interface cards.

For this system (bus/interface): The project implements a 1581-compatible drive with a Commodore serial IEC interface rather than installing inside the C64. The primary project page does not enumerate every possible IEC host, so broader Commodore compatibility is not inferred here.

No assembled seller or current PCB supplier was verified. A build needs PETCPU and DRVIO cards, a backplane, components, a suitable 720 KB drive mechanism, a legal 1581 ROM image, power, cabling, and an enclosure. DRVIO revision 1.1A is marked okay and was tested with double-density PC drives; PETCPU revision 1.1B publishes board files but its layout is marked untested. High-density operation can overclock the WD1772 and is not the documented 1581 configuration.

Turns a C64 or C128 into a stand-alone SID synthesizer with keyboard performance, real-time controls, MIDI support, and optional six-voice stereo.

For this system (exact model): The maker designed Cynthcart for the C64. Basic operation needs the computer, a safe modern power supply, and an audio cable. MIDI requires a supported Datel, Passport, Sequential, or Kerberos interface; using another expansion-port cartridge at the same time can require an expander. A second SID enables stereo and six-voice modes.

Protovision showed 12 orange Cynthcart 2.0.1 cartridges in stock at EUR 38 with a one- to two-week shipping estimate on 2026-07-28. The maker also publishes ROMs and source for personal use, but does not permit third-party cartridge sales. The project page labels 2.01 current while also listing a 2.0.2 source reorganization, so check the included ROM revision if that distinction matters.

Three-slot C64 and C128 cartridge-port expander with per-slot switching, a fuse, status LEDs, and reset.

For this system (exact model): The current reproduction is explicitly sold for the Commodore 64. It is not compatible with the Commodore 64 Ultimate or Ultimate 64.

AMI64 presented a current-priced listing on 2026-07-27. The seller explicitly excludes the Commodore 64 Ultimate and Ultimate 64. Cartridge combinations can still conflict electrically or in the memory map, so change connections only with power off and enable only known-compatible combinations.

Connects a Commodore expansion port to external MIDI equipment through MIDI In, Out, and Thru sockets.

For this system (exact model): The current seller explicitly names the C64. Use software that supports the Datel register layout. Cynthcart needs both cartridges connected through a compatible expander such as Mini X-Pander+.

Human review confirmed on 2026-07-28 that the linked seller item is currently orderable. The seller says the cartridge includes instructions; Cynthcart, an expander, software, and MIDI cables are separate.

Adds four 8-bit digital audio channels with stereo output through the Commodore user port.

For this system (exact model): The seller explicitly names the Commodore 64. DigiMAX plugs into the user port, uses CIA 2 Port B and Port A control bits, and outputs through a separate stereo mini-jack. A suitable cable or mixer is needed to combine it with SID audio.

The Shareware Plus page was last updated on 2025-08-01 and then claimed email ordering, but it exposes no conventional store or current checkout path. HR-061 confirmed that the original maker URL is gone and closed with direction to stop pursuing the unread Mk2 path for now. Availability remains unknown; PCBWay says the author stopped sharing the Mk2 there.

Historical breadboard adapters for prototyping through a Commodore control port or the VIC-20 expansion port.

For this system (exact model): The joystick-port variant explicitly supports the C64 and exposes Up, Down, Left, Right, Fire, Pot X, Pot Y, +5 VDC, and ground on labeled breadboard pins. The breadboard is not included. Do not assume buffering or protection, and connect or remove the adapter only with power off.

C64 OS preserves the former $13 joystick and $19 VIC-20 listings, but no current product was exposed on Dorktronic's eBay profile in July 2026. The joystick item URL also failed two Tavily extractions after the required 60-second retry and is logged as WF-062. Treat both boards as used-market finds. Documentation was not included. Both designs expose computer power and signal lines directly; the VIC-20 feature explicitly warns that improper prototyping can damage the computer.

Open 1 MB C64 flash-cartridge family that can be reprogrammed directly by the computer without an EPROM programmer.

For this system (exact model): EasyFlash supplies 1 MB of banked flash and supports normal 8 KB, normal 16 KB, Ultimax, Ocean Type 1, EasyFlash, and EasyFlash xbank modes. It is not a general disk replacement or freezer cartridge. EasyFlash 1CR is functionally equivalent but omits the original board's reset button.

The EasyFlash and EasyFlash 1CR designs remain buildable. Poly.play's assembled original-style EasyFlash was out of stock on 2026-07-30.

Open C64 flash cartridge with seven EasyFlash slots, eight external KERNAL slots, freezer-cartridge support, and USB transfer.

For this system (exact model): The maker documents seven full EasyFlash slots, eight external KERNAL slots, and Action Replay, Retro Replay, Nordic or Atomic Power, and Super Snapshot 5 freezer-image support. External KERNAL replacement does not require opening or wiring the C64.

AMI64 described its assembled EasyFlash 3 as newly available on 2026-07-30. The package includes the cartridge and a printed quick-start guide; a USB cable and any separate C64 storage device are not listed as included.

A current replacement supply for Commodore 1541-II and 1581 drives, offered in Basic, adjustable, and higher-capacity PRO versions.

For this system (bus/interface): This powers a 1541-II or 1581 peripheral rather than the C64 itself. The standard version has one four-pin DIN drive output; only the PRO version is documented for two 1541-II drives or a 1541-II plus 1581.

Electroware listed the family from EUR 36.99 with dispatch in three to five days on 2026-07-30. Select the correct mains option and exact Basic, Adjust, or PRO configuration. Only the PRO description permits two drives, and the published 5 VDC and 12 VDC capacities differ from C64Lover's separately indexed supply.

Current protected replacement supplies with separate direct-connect C64/VIC-20 and C128 versions.

For this system (exact model): Choose the C64 version with its round seven-pin output. The seller explicitly supports the C64 breadbin, C64C, and C64G. Match the regional mains option and attach the supply only with computer power off.

On 2026-07-30, Electroware listed the eleventh-revision C64 version at EUR 46.99 and the twelfth-revision C128 version at EUR 52.99, both with dispatch in three to five days. Each has regional mains choices and an optional Adjust and Protect trim of roughly 4.9 to 5.3 V. Buy the direct version for the computer; the C64 model reaches a C128 only through a separate adapter.

A single replacement supply that powers a C64 or later VIC-20 together with a 1541-II or 1581 floppy drive.

For this system (exact model): The seven-pin computer lead directly supports the C64, C64C, and C64G. The second output is for one 1541-II or 1581 drive. Match the mains configuration and attach all cables with power off.

Electroware listed the twelfth-revision supply at EUR 68.99 with dispatch in three to five days on 2026-07-30. Regional mains configurations and an optional Adjust and Protect 5 V trim are offered. C128 use requires a separate C64-to-C128 adapter; choose and verify that adapter rather than connecting the C64 lead directly.

A calibrated cassette-port display that measures the computer's live 5 V rail while preserving the Datasette connection.

For this system (exact model): The seller explicitly supports the C64 and measures the 5 V rail through its cassette port. The pass-through preserves Datasette signals. Attach or remove the meter only with power off.

Electroware listed the factory-calibrated meter at EUR 18.99 with dispatch in three to five days on 2026-07-30. It measures the live 5 VDC rail only. It does not display 9 VAC, apply a test load, regulate voltage, or automatically disconnect a failing supply.

Modern VIC-1011-style user-port RS-232 adapter with status lights, reset, and a software-dependent 9600-baud mode.

For this system (exact model): Standard user-port mode supports up to 2400 baud. Jumper-selectable UP9600 mode reaches up to 9600 baud with Novaterm or Striketerm.

Tindie marked the adapter out of stock on 2026-07-30 and says it has been sold out since 2026-01-05. A DB25-to-DB9 adapter is an optional passive accessory, not a separate catalog product.

Cartridge fast loader for a Commodore 64 or 128 using an existing SD2IEC device or Commodore 1541-family disk drive.

For this system (exact model): The current seller explicitly lists the C64. Connect a compatible SD2IEC or 1541-family drive separately; the cartridge does not replace the drive.

TFW8b exposed an active product page with selectable options on 2026-07-27. This is an accelerator for an existing storage device, not storage by itself. Loading speed and compatibility depend on the program and attached drive.

Period user-port adapter for connecting low-speed RS-232 equipment to Commodore 8-bit computers.

For this system (exact model): Standard mode supports up to 2400 bps. Novaterm 9.6 can use the documented UP9600 jumper configuration for operation through 9600 bps.

The surviving builder document describes the original kit and its setup, but no current sale or complete public fabrication package was verified. Look for an original assembled adapter or kit on the used market.

Current and DIY versions of the C64 and C128 utility cartridge with fast loading, freezer, monitor, BASIC extensions, and desktop software.

For this system (exact model): The original manual, current 101% project, and III+ project explicitly target the C64. Turn the computer off before inserting or removing any version. The original manual also says never to invoke the freezer while the disk drive is running. The 101% cartridge must be flashed before first use; the DIY III+ board needs a programmed EPROM.

Daniel Mantione currently offers the assembled Final Cartridge III 101% with a case through his project page and SellMyRetro. It arrives without firmware, so the buyer must flash a compatible image before use; version 2 of the 101% firmware and the C64 flasher are available from the maker. The separate C64iSTANBUL III+ project offers an orderable through-hole PCB, bill of materials, and 64 KB or 256 KB EPROM images, but it requires assembly and an EPROM programmer. PCBWay labels that shared hardware project CC BY-SA 3.0. The original and derivative firmware remains copyrighted and is not presented as freely licensed.

Maps an independent second gamepad button to Up while preserving the controller's normal directional Up input.

For this system (exact model): MicroMiga names the C64 and recommends the approximately 50 cm Slim version where connector clearance is limited. Use a controller with an independent second button.

MicroMiga listed the family from EUR 8.99 on 2026-07-30. The extracted variation table explicitly marked the short FAT version out of stock but did not expose a reliable stock state for the longer, slim machine-side version, so confirm the desired model before ordering. A controller needs genuinely independent fire buttons; duplicated or cloned fire buttons do not work for the remapping.

Adds a software-controlled FM receiver to a Commodore 64 or 128 through the user port, with an optional real-time clock and station storage.

For this system (exact model): The assembled board plugs directly into the C64 user port and sends received audio through its own stereo output. An optional DS3231 module can add a clock and saved stations. Use an original disk drive for the supplied software because the seller says SD2IEC and similar devices are incompatible.

Protovision showed eight units in stock with a one- to two-week shipping estimate on 2026-07-29. The optional DS3231 module and its CR2032 or LIR2032 battery are not included. The seller says the supplied software is incompatible with SD2IEC and similar devices and strongly recommends an original disk drive.

Adds nine channels of OPL2-compatible FM synthesis to a Commodore 64 and can mix SID or other audio into its output.

For this system (exact model): The maker and seller explicitly identify the C64. FM-YAM uses I/O 2 at $DF00 and has no MIDI hardware of its own. A Datel-compatible MIDI cartridge can coexist through a suitable expander because it uses I/O 1 at $DE00, but other cartridges can conflict. Use the documented audio cables and mixer arrangement.

The project page says all four production batches, totaling 360 cartridges, sold out. Commodore4Ever also showed its product page sold out on 2026-07-28, and Protovision's current music-peripherals category listed only FM-YAM cable accessories. Check the seller pages or used market for a restock.

FPGA-based pin-compatible 6581 and 8580 replacement with two complete SIDs, six-voice stereo, analog inputs, paddles, and mouse support.

For this system (exact model): The maker says FPGASID works in any C64. Basic chip replacement is socketed and does not require soldering, but stereo use and some second-SID addresses require the documented cable and configuration. Address $DE00 can conflict with expansion-port hardware.

Human review confirmed on 2026-07-28 that the advertised KryoFlux store item is gone. The project documentation, firmware, and configuration software remain available, and used units can still be searched for. An interrupted firmware update can require JTAG recovery.

Connects one six-button Sega Mega Drive or Genesis controller to both C64 or C128 control ports with port switching and extra button mappings.

For this system (exact model): The adapter occupies both control ports and accepts one Sega controller. The detailed V2 operation report is C64-specific and documents Start-based port switching, extra fire and Up mappings, autofire, status lights, and optional BackBit menu return.

BackBit says it no longer has capacity to build this former product and has released the design under GPL-3.0. The repository supplies KiCad board and schematic files, CUPL source, printable case files, and a bill of materials; a build also needs the listed ATF1502 CPLD and an ATDH1150USB programmer. The former store URL returned 404 twice, including after the required 60-second retry.

Provides 1 MB or 4 MB of geoRAM-compatible cartridge memory for the Commodore 64 and 128.

For this system (exact model): Both GGLABS project pages explicitly name the Commodore 64 and document successful memory-test and GEOS use. These are geoRAM expansions, not DMA REUs, and the full 4 MB requires software that supports the extended bank range.

GGLABS marks both technical projects released, but the current GRAM/4D Tindie listing says the seller is taking a break and no current GRAM/1D order path was verified. The published pages are useful technical documentation but do not expose a complete fabrication package. GeoRAM-aware software is required. GEOS 2.0r can use at most 2 MB; the full 4 MB needs patched GEOS 2.0r+, GEOS MP3, Wheels, or another compatible program.

Modern VIC-1011A-style user-port adapter with a DB9 RS-232 connection for the Commodore 64 and 128.

For this system (exact model): The adapter connects to the user port and supports standard software through 2400 baud. Novaterm or Striketerm can use the documented UP9600 jumper mode for operation through 9600 baud.

The Tindie seller was taking a break on 2026-07-30 and did not expose an ordering path. GGLABS publishes a schematic for the current revision, but the page does not present a complete fabrication and assembly package.

Expansion-port UART family with SwiftLink-compatible GLINK232 and faster Turbo232-compatible GLINK232T forms.

For this system (exact model): Both variants plug into the expansion port and can be mapped at $DE00 or $DF00 with IRQ or NMI. GLINK232 supports the SwiftLink table through 38400 baud. GLINK232T testing reached 38400 with Novaterm 9.6c and 115200 with GTERM 0.18; its 230400-baud register setting is not a promise of practical throughput.

GLINK232 A03 remains buildable from its schematic, Gerbers, and component-option tables. The faster assembled GLINK232T was unavailable while its Tindie seller was taking a break on 2026-07-30, and its page does not provide a complete fabrication package. The seller text misprints the top T rate as 203400 baud; the maker's overview and register table specify 230400 baud.

User-port USB serial adapter for linking supported Commodore 8-bit computers to a modern host's virtual COM port.

For this system (exact model): The adapter connects the C64 user port to a modern computer as a USB virtual COM port. Standard software supports up to 2400 baud; Novaterm or Striketerm can use UP9600 through 9600 baud.

The Tindie seller was taking a break on 2026-07-30 and did not expose an ordering path. GGLABS publishes a schematic, but the page does not present a complete fabrication and assembly package.

Adds high-speed Wi-Fi networking, file-transfer protocols, and SD-card storage to computers with a standard RS-232 interface.

For this system (bus/interface): GuruModem does not plug directly into a stock C64. C64 OS documents it through a separate high-speed RS-232 interface such as GLINK232 or Turbo232, with the host interface and terminal software determining the usable rate.

The maker page exposed direct eBay, Sphere Cube, and Arcade Shopper purchase routes on 2026-07-30. Tavily could not independently extract the exact eBay or Sphere Cube destinations, recorded as WF-044 and WF-045, so confirm current stock before ordering. A user-supplied 5 V micro-USB supply is required; the SD card, serial cable, and computer-specific adapters are not included.

Open low-power 2 MB geoRAM-compatible expansion cartridge for the Commodore 64.

For this system (exact model): Plugs into the Commodore 64 cartridge port. Use only with software that supports geoRAM-compatible memory; REU-only software cannot use it. GEOS requires a separate geoRAM driver installation.

The assembled Tindie cartridge was out of stock on 2026-07-24 and had been sold out since June 10, 2024. The open design remains buildable. This is geoRAM memory, not an REU: software must explicitly support geoRAM. Most C64 programs use neither expansion-memory type, and GEOS needs an added geoRAM driver on its boot disk.

Replaces a C64 RF modulator with FPGA-generated 1080p HDMI video and digitized stereo audio while retaining analog video.

For this system (exact model): The manual covers shortboard Assy 250469 and all other original longboards. Installation removes the original RF modulator, solders board headers, and inserts an interleaver under the VIC-II. Longboards also need 5 V and ground wires at the expansion port. The C64 must retain a compatible VIC-II, and the HDMI display must accept 1920x1080p over HDMI 1.4 or later.

Authorized seller Retro-Updates listed hardware version 0.2 at EUR 109.00 on 2026-07-27. Confirm the exact revision and production batch before ordering: the manual documents incorrect chroma resistors in the first version 0.2 production batch, an ineffective PLL-adjustment jumper on batches 1 and 2, and a transmitter issue that prevents HDMI audio on a small minority of displays.

Vintage C64 machine-language monitor cartridge with assembly, debugging, memory, and relocation tools.

For this system (exact model): The original manual is specifically for the C64. Turn the computer off before inserting or removing the cartridge. HES MON uses RESTORE as a monitor-entry key, occupies 33 bytes near the bottom of the machine stack, and warns that RS-232 files do not work correctly while the cartridge is installed.

ConsoleMAD listed one original cartridge-only unit at GBP 24 on 2026-07-30; it was missing its label. RavenWolf's tested USD 12 cartridge was sold out and had been recovered from a workshop with harsh long-term storage conditions. Treat every offer as an individual used item. The HES software and manual remain copyrighted, so this record does not present an unlicensed ROM download as a DIY route.

C64 cartridge that provides an 80-character text display and is intended for use with a modern flat-panel display.

For this system (exact model): The listing explicitly identifies the Commodore 64 and describes an expansion-port cartridge that displays 80 characters per text line. It does not make a separate Commodore 128 compatibility claim.

Poly.play listed Highspeed80 at 17 EUR, available immediately, on 2026-07-30. The seller gives a normal German delivery estimate of 3 to 10 working days and notes that international delivery can differ. The product page recommends a TFT display.

Rebuilds a Commodore 64 around a modern replacement motherboard with improved power, protection, video, diagnostics, and ROM switching.

For this system (exact model): This is a C64-compatible replacement motherboard, not a complete computer. The build guide primarily calls for parts from Commodore assemblies 250407, 250425, KU-14194HB, or similar boards, plus new passive parts and a Kernal EPROM. Check every donor chip and PAL or NTSC option against the BOM before assembly.

CBMSTUFF marks the motherboard discontinued. Its product page, build manual, BOM, and supporting software remain online, and some optional parts remain listed. Used boards may occasionally appear on secondary markets.

Adds CompactFlash and ATA or ATAPI mass storage plus USB PCLink transfers to a Commodore 64 expansion port.

For this system (exact model): IDE64 plugs into the Commodore 64 expansion port. The official project also names the C128. A CompactFlash-only setup needs no additional power supply; other device configurations and firmware upgrades require the applicable IDE64 documentation.

The official project site is active and identifies V4.2 as the latest revision, but the selected official pages provide neither a current order path nor a complete fabrication package. Check the used market and confirm the hardware revision before buying.

Rehouses an original or replacement Commodore 64 motherboard in a newly manufactured C64c shell made with the original injection molds.

For this system (exact model): The seller describes the shell as suitable for an old C64 or C64c and names C64 Reloaded MK2 as an example replacement board for a new build. Confirm motherboard mounting points, rear connector openings, keyboard type and mounting hardware, power-LED dimensions, and any shielding required for the exact build.

Individual Computers listed the Breadbin Gray version for EUR 59.50 and immediate delivery on 2026-07-30. Its explicit variant route also listed a transparent polycarbonate version for immediate delivery. The transparent shell can show small bubbles and surface marks because the original molds were not designed for transparent material. Historical Pixelwizard offerings included Breadbin Gray, Classic Beige, Retro Black, and SX-64 Style cases, but that 2017 range must not be treated as the current color list. The default unqualified product route failed twice under WF-072; use an explicit current variant page.

Replaces the power light with a two-color indicator that shows the computer's IRQ-line state.

For this system (exact model): Shareware Plus offers separate round-LED breadbin and rectangular-LED C64C versions; the C64C version has a 40 cm cable because its LED is farther from the cartridge port. The seller and review specify cartridge-port pins 1 for ground, 3 for +5 V, and 4 for IRQ. TEBL's open board is documented for a breadbin-style C64 and warns that reversing ground and +5 V will destroy its logic IC.

Shareware Plus said the C64 breadbin, C64C slimline, and VIC-20 versions were in stock at GBP 9 each plus postage on 2026-01-25 and accepts email orders. The tebl C64 design is buildable under CERN OHL v1.2. This is an IRQ-line indicator, not a complete CPU-usage or disk-activity meter. Installation opens the computer and places clips on cartridge-port ground, +5 V, and IRQ contacts; verify every connection with power off.

Arduino-based C64 cartridge family for fast PRG loading from SD storage or a serial connection.

For this system (exact model): This is a C64 expansion-port cartridge. It is primarily a PRG loader rather than a 1541 or IEC drive emulator; the older seller page says CRT support is very limited and capped at 8 KB. The original maker described Bluetooth serial loading as possible but not successfully tested at that time. A 2020 EasySD demonstration identifies a Bluetooth-equipped IRQHack64 build, but the module, setup, and current sales status are not documented well enough to treat Bluetooth as a standard feature.

Gotek Retro lists IRQHack II at EUR 25 including its housing and provides a current order-interest form. The form offers an IRQHack II package with a populated SD card but explicitly has no stock management or availability guarantee and ships only within Europe, with non-EU European destinations handled case by case. Confirm stock and included media before ordering.

DIY replica of the 1985 C64 freezer cartridge that captures RAM, I/O, and CPU state to disk.

For this system (exact model): The original manual and replica project explicitly target the C64. Install the cartridge only with the computer off and follow the documented switch sequence. A 1541 or Enhancer 2000 uses the fast disk routines; other documented serial drives operate at normal speed. Snapshot success depends on the target software fitting in memory and leaving enough compressible or free space.

The replica repository's 2021 v1.0a files include ISEPIC-named Gerbers, an Altium PCB project, schematic, bill of materials, and disk images. Its README mistakenly links its PCBWay order button to a different 8 MHz Z80 card; do not order that board as an ISEPIC. Review and fabricate from the included ISEPIC files instead. Replica hardware files outside the Docs and Software directories are CC BY-NC-SA 4.0. The original 1985 ISEPIC software remains copyrighted and is not covered by that hardware license.

Current FPGA replacement for MOS 6526 and 8521 CIA chips with selectable old- or new-CIA behavior.

For this system (exact model): The maker tested all C64 mainboard revisions and numerous peripherals. J-CIA64 defaults to 8521 mode; bridge the documented underside jumper only when older 6526 behavior is required. Clockwork64 is a known reported incompatibility. The thicker turned pins can stress some leaf sockets, and RF shielding must not contact the module.

The official project page links multiple current retailers, and AmericanRetro exposed a direct Buy Now route on 2026-07-30. The maker says the implementation passes its diagnostic and software suites but explicitly warns that a reproduction cannot be guaranteed identical under every hardware and software combination. Clockwork64's maker separately reports problems with J-CIA replacements.

Current FPGA replacement for MOS 6510 and 8500 processors, including the documented instruction set and cycle behavior.

For this system (exact model): AmericanRetro says J-CPU64 was tested with all C64 mainboard revisions, explicitly including 250469, 250466, 250425, 250407, and KU-14194HB, plus EVO64 revisions. It was also tested with several storage, network, input, and cartridge peripherals. Confirm pin 1 and socket alignment before applying power.

The official project page links three current retail channels, and AmericanRetro exposed a direct Buy Now route on 2026-07-30. The retailer describes a same-size, no-soldering drop-in replacement; that assumes the original CPU is already socketed. A soldered CPU still requires proper desoldering and a suitable socket.

Vintage and DIY C64 freezer cartridge that saves restartable memory snapshots to disk, tape, or EPROM-oriented cartridge files.

For this system (exact model): The archive documents exact C64 operation. Pressing Freeze triggers an NMI and stores CPU state in the cartridge's 8 KB RAM before writing restartable memory-dump files. Optional drive-RAM capture does not restore drive RAM, and captured disks use extra fast-loader data in track 18 sectors 15 and 18 that ordinary file copying can miss.

DDI's Re-Capture page still exposes Gerbers, a parts list, a Capture ROM archive, and a manual link. The parts list specifies the EPROM, SRAM, logic, passives, and switch choices, but ReplayResources says the schematic is still missing and no complete assembly or test guide was found. Neither page supplies a clear license for the reproduction files or Capture software. ReplayResources quotes permission relating to Jason-Ranheim's separate Promenade materials but explicitly says its own Capture permission requests went unanswered, so the catalog does not treat the Capture ROM as open or freely licensed. Original cartridges remain worth searching for used.

Licensed replacement computer and disk-drive ROM system that accelerates Commodore serial storage and adds DOS commands.

For this system (exact model): The official description explicitly covers the C64. A physical Commodore drive normally needs its matching licensed JiffyDOS drive ROM, while SD2IEC-based storage already implements the protocol.

The official licensing site listed five authorized sales channels on 2026-07-27. Offerings include licensed ROM images, replacement ROM overlays, and switchless overlays; stock and the exact supported machine or drive vary by seller.

Connects a legacy analog PC game-port joystick or steering wheel to a Commodore 64 as paddles or a digital joystick.

For this system (exact model): Connects a legacy DB15 analog PC joystick or steering wheel to a C64 control port. Select and calibrate paddle or digital mode for the game; this is for conventional game-port controllers, not USB devices.

Poly.play showed Jocopod available immediately at EUR 33 with a three- to ten-workday German delivery estimate on 2026-07-30. The optional 2.3-meter digital foot pedal was listed separately at EUR 15 but was out of stock; it is an accessory to Jocopod and remains folded into this record.

Adds about 1.7 meters of reach between a compatible nine-pin controller and its vintage computer.

For this system (exact model): Both current sellers explicitly market a joystick extension for the C64. Extend only a controller already verified for the computer.

AutumnHippo exposed an add-to-cart route at USD 7 on 2026-07-30. Protovision separately showed ten joystick extension cables in stock at EUR 10 with a one- to two-week shipping estimate. The exact long and short products pictured by the C64 OS guide are not identified, so the catalog keeps current length and seller variants together.

Provides a new 1.7-meter nine-conductor lead for repairing compatible vintage joysticks and controllers.

For this system (exact model): The seller explicitly lists C64 controllers. This is a solder-in controller repair lead, not a cable that plugs directly into an intact joystick.

AutumnHippo exposed an add-to-cart route at USD 7 on 2026-07-30. Basic soldering is required. Trace the existing cable or controller circuit before removal: the seller explicitly warns that wire colors can differ and that systems sharing a nine-pin plug do not necessarily share controller wiring.

Swaps both Commodore 64 control ports at the press of a button without moving the connected controllers.

For this system (exact model): The seller explicitly supports both breadbin and C64C systems. The board occupies both control ports and swaps their complete joystick, mouse, pen, and paddle signal assignments.

The no-case version showed four units in stock at EUR 32 on 2026-07-30. The listed range through EUR 42.90 includes the optional black 3D-printed case. A brass standoff supports the board while its illuminated button is pressed.

Passive cable for powering a Commodore 64 from an external Commodore 128 power supply.

For this system (exact model): The rectangular five-pin female end accepts an external C128 supply and the round seven-pin male end connects to the C64. Match the exact supply output and adapter direction, inspect old power hardware, and connect or disconnect only with power off. The cable adds no over-voltage protection or current capacity.

Keelog listed the 22 cm adapter at USD 23.99 or EUR 20.99 on 2026-07-30. The product is manufactured in Poland and was presented through a live order form. The seller warns that the passive adapter only conveys power and does not guarantee that an attached supply can provide sufficient current.

Protected regional replacement supplies for the C64, later VIC-20, and C128 in Classic, Modern, and current RetroPower enclosures.

For this system (exact model): Choose a C64 electrical variant with the round seven-pin output and 5 VDC 2 A plus 9 VAC 1.1 A ratings. Classic, Modern, color, and regional-plug choices do not change the documented computer output.

Keelog's current family pages listed regional C64 and C128 supplies on 2026-07-30. Representative EU Classic or Modern products were USD 65.99 or EUR 57.99. Classic measures 86 by 70 by 48 mm; Modern measures 125 by 59 by 42 mm, with black and gray choices. Keelog also identifies RetroPower as the successor enclosure. Match the computer branch, connector, mains voltage, and regional plug rather than selecting by case style alone.

Protected dual-output supplies for a C64 or later VIC-20 and a 1541-II, 1571-II, or 1581 floppy drive.

For this system (exact model): The included device cable has a seven-pin C64 plug and a four-pin drive plug. The drive branch supports one 1541-II, 1571-II, or 1581. Match the regional mains version and connect all equipment with power off.

Keelog listed current regional RetroPower, Classic, and Modern configurations on 2026-07-30. The representative RetroPower US model was USD 89.99 or EUR 78.99 and included its device cable. Select the correct 120 V or 230 V version and regional plug. The current RetroPower page calls that enclosure the successor to the earlier Classic and Modern styles.

A repairable metal-cased C64 replacement supply with fused 5 VDC and 9 VAC sections, a power switch, and optional C128 or Plus/4 adapters.

For this system (exact model): The updated supply is explicitly designed for the C64. Verify the local mains requirement and connector before ordering, and power the computer off before connecting or disconnecting the supply.

The newest readable announcement was published on April 18, 2022 and listed the Nu-Brick 64 at USD 65 plus USD 15 shipping, with C128 and Plus/4 pigtail adapters at USD 15 each. It directs buyers to message Kevin Ottum on Facebook. No current stock or price page was verified on 2026-07-30, so confirm that he is still accepting orders and specify the required computer and connector.

Intercepts the C64 keyboard matrix to add programmable shortcuts, macros, remapping, remote control, and sixteen hardware-control lines.

For this system (exact model): The connectors, key names, typing command, and examples follow the C64 keyboard. Install it between the keyboard and motherboard, select a safe shared 5 V source, and follow the revision 4 power and cable instructions. Earlier revision 3 boards need the documented USB circuit correction.

The maker currently offers revision 4 assembly kits with a PCB, preprogrammed ATmega, and components except connection cables for EUR 30 by email. Kits are made in small spare-time batches and may require prepaid backordering. Version 1.6 firmware, configuration tools, Gerbers, KiCad design files, schematics, and source remain downloadable.

Open microSD cartridge that emulates many C64 and C128 cartridge formats and loads programs and disk images.

For this system (exact model): The current project supports PAL and NTSC C64 systems, but software-defined bus timing can vary by machine and may require phi2 offset adjustment. Disk emulation uses KERNAL vectors, so fast loaders, direct drive access, REL files, and some DOS commands are unsupported.

Retro Electronics listed one assembled cartridge in stock on 2026-07-25 without a microSD card. Lotharek also exposed a current order path on 2026-07-27 for a redesigned board in a transparent case. Retro Electronics installs Version 1.35 by default and treats its NTSC build as work in progress; check the current Codeberg releases before use.

Open SwiftLink-compatible expansion-port UART design for connecting supported Commodore computers to DB9 RS-232 equipment.

For this system (exact model): Link232 requires an open cartridge slot and a suitable DB9 RS-232 cable. Existing SwiftLink software expects the lowest selectable 16-byte I/O bank.

RETRO Innovations does not sell assembled Link232 cartridges. The maker publishes EAGLE schematic and PCB files for builders. A separately mentioned future Turbo232-compatible revision has no documented release and is not part of this record.

Combines a SwiftLink-compatible high-speed serial cartridge with an ESP8266 Wi-Fi modem for Commodore 64 and 128 systems.

For this system (exact model): The maker explicitly supports the Commodore 64. The cartridge occupies the expansion port and normally uses DE00/NMI; select a compatible address and interrupt setting for the intended SwiftLink-aware software and other installed hardware.

The assembled Tindie listing was retired by 2026-07-30. The project repository retains Eagle design files, case files, firmware, software patches, and setup documents. The maker says prebuilt units sometimes appear through the linked eBay seller page, but no specific current listing was verified.

Adds a hardware azimuth indicator to a Commodore 1530 Datasette so its tape head can be aligned without running a program.

For this system (exact model): The open project explicitly describes attaching the board to a C64 Datasette, while Shareware Plus names the Commodore 64 and the C2N 1530. Build or buy the correct board and mechanical parts for the drive revision, follow the wiring images, and establish the alternate solder points before modifying a different Datasette PCB.

The GPLv3 reverse-engineering files remain available. Shareware Plus described a small reproduction batch at GBP 16, with an optional GBP 6 brass adjustment rod and GBP 5 printed support, but that page was last updated on 2025-01-01 and uses email ordering. Confirm present stock and exactly which parts are included. Installation modifies a Datasette and requires soldering to points that can differ between PCB revisions.

Breaks a compatible C64 video socket out to S-Video, composite video, and RCA audio.

For this system (exact model): Compatible only with C64 revisions having the six-pin-compatible video socket identified in human review. Do not assume that a five-pin or eight-pin socket fits. Jumper off attenuates chroma for displays that need it; jumper on passes chroma directly.

The product exposed a login-or-register-to-buy path on 2026-07-28. Human review says it works only with C64 units having the compatible six-pin video socket, so it is not presented as universal across C64 revisions. Check the computer's physical socket against the seller photographs before ordering. The page's AUDIO_IN header description is garbled and is not treated as usable documentation.

CPLD replacements for failed PLA chips, currently sold for Commodore 264-series computers and previously made for the C64.

For this system (exact model): The archived seller page describes a separate C64 PLA replacement. It is discontinued, and the page does not identify safe board revisions, package, socket, clearance, or orientation details; verify all of them before buying or fitting a used module.

The 264-series module exposed a login-or-register-to-buy path on 2026-07-27, while the separate C64 version is discontinued. Human review says the module plugs into the original socket, but the seller does not establish that every supported motherboard is socketed or document the original MOS part, board revisions, orientation, removal, or clearance. Treat it as a plug-in replacement only after confirming a compatible socket and orientation. A used C64 module needs the same checks.

Adjustable VIC-II interposer intended to reduce vertical jail bars and S-video chroma artifacts.

For this system (exact model): Install the board between the C64 motherboard and VIC-II. A soldered VIC-II must first be removed and replaced with a 40-pin socket; incorrect orientation can damage the VIC-II or other components. The seller does not distinguish motherboard revisions.

Retro Electronics listed one assembled LumaFix64 in stock at 16.50 GBP on 2026-07-30.

VIC-II interposer combining LumaFix video cleanup with a replacement C64 clock-generator circuit.

For this system (exact model): The seller explicitly lists Assy 250425, 250466, 326298, 250407, KU-14194, and C64 Reloaded MK1. Assy 250469 is not named, and an independent hands-on report explicitly excludes C64 Reloaded MK2.

Protovision listed the PAL LumaTOLB at 25 EUR but temporarily unavailable with unknown delivery time on 2026-07-30. The current listing gives a three-year warranty and says the original timing chip need not be removed. Installation may require replacing the VIC-II heat shield with a larger one. A hands-on 2018 report says LumaTOLB does not work with C64 Reloaded MK2, although the separate original LumaFix does. No current NTSC order path was verified.

Emulates Commodore IEC devices and loads files from local flash, an SD card, or network servers over Wi-Fi.

For this system (exact model): The project explicitly supports the Commodore 64 through its IEC serial port. Select a documented ESP32 hardware profile and matching firmware before connection.

The project provides source, several ESP32 hardware profiles, build instructions, and a browser-based firmware flasher. No direct retail source was verified, so builders must select matching hardware and firmware before connecting it to a computer.

Replaces a Commodore 64 keyboard with a modern Gateron-switch mechanical assembly in breadbin or C64C cases.

For this system (exact model): The replacement fits both breadbin and C64C slim cases and supports original long and short C64 motherboards plus C64 Reloaded and Ultimate64 replacement boards. Long motherboards in a slim case need a longer keyboard cable. Verify cable orientation at the missing connector pin before power-up.

AmericanRetro.shop offered assembled and kit versions, and its Tindie assembled listing showed two revision 1.07 units at USD 194.99 on 2026-07-30. MtnBuffalo also publishes revision 1.07 fabrication, bracket, firmware, bill-of-materials, and assembly files. The physical product and MechBoard64 brand require separate permission for commercial manufacture even though the published design files permit personal building and modification.

Converts composite, S-Video, RGB, RGBI, and VGA-family retro signals to simultaneous digital and analog DVI-I output.

For this system (exact model): The product documentation lists Commodore 64 PAL support. Use a correctly wired composite or S-Video SCART cable; the C64 does not provide native analog RGB.

The European SCART and Japanese JP21 Revision B pages exposed login-or-register-to-buy paths on 2026-07-27. Never connect an EU SCART cable to the JP21 version: the seller says the different pinout can damage the device. The newest dated hardware announcement says units made since June 2025 have a larger OLED and USB-C power, but an older section still says Micro-USB. Human review found no package clarification, so confirm the connector, power requirement, and included USB items with the seller. A DVI-to-HDMI cable and source-system cables are sold separately. Medusa line-doubles when needed but does not change vertical refresh rate, so the destination display must accept the resulting 50 or 60 Hz signal and may blank briefly when the source changes resolution. Install only firmware matching the hardware revision.

Connects a PS/2 mouse to Commodore, Amiga, Atari ST, and Atari 8-bit computers with host-specific mouse, joystick, paddle, and tablet modes.

For this system (exact model): Default mode emulates a 1351 mouse and supports the wheel in compatible software. Forced modes include NEOS mouse, digital joystick, Amiga mouse, paddles, and Koala Pad. The computer must have a working SID analog-input path.

The official shop listed immediate delivery from EUR 34.07 on 2026-07-30. Protovision listed five units from EUR 38, with the slim connector costing EUR 3 more. The slim version fits every supported computer; the wider screw-in version has documented clearance exclusions including the Amiga 600 and Atari 1200XL. A USB mouse works only if the mouse itself supports the PS/2 protocol through a passive adapter.

Compact two-connector cartridge-port expander with an upright slot and reset button for C64-family computers.

For this system (exact model): The current Mini X-Pander+ listing explicitly names the C64 and C64C. It is not compatible with the 1541 Ultimate 2.

Protovision showed 12 Mini X-Pander+ units in stock with a one-to-two-week shipping estimate on 2026-07-27. The seller explicitly says it is not compatible with the 1541 Ultimate 2. Two enabled cartridges must use compatible bus signals and different address ranges.

Small C64 cartridge that flashes one PRG file of up to 50 KB for immediate cartridge startup.

For this system (exact model): The cartridge accepts one PRG file up to 50 KB. Programming requires the source file on a device addressed as 8 or 9, such as a disk drive or SD2IEC. The seller does not claim CRT, disk-image, freezer, or multi-slot functions.

Poly.play reported low stock and a normal add-to-basket path on 2026-07-30. The package includes the cartridge, English and German manual, cardboard box, and stickers.

Open dual-SID board with mixed 6581 and 8580 support, runtime address selection, channel mixing, paddle compatibility, and stereo output.

For this system (exact model): The maker documents boards 250407, 250425, 250466, and 250469 in breadbox and flat cases. Early 326298 and KU14194HB boards probably do not fit. The builder must set motherboard type, both SID models, voltage, filters, and output components correctly before inserting either chip.

The complete GPL-2.0 hardware, GAL, Gerber, and build documentation remains available. A Tindie assembled listing reported out of stock since 2020 but says the seller may assemble a unit on demand; treat that as a contact route rather than stocked availability. SID chips are excluded.

Adds hardware MP3 decoding and stereo audio output to a Commodore 64 through an MMC64 or IDE64 V4.1 host.

For this system (exact model): The official page presents MP3@64 as C64 hardware but requires a compatible MMC64 or IDE64 V4.1 host. The module is not a stand-alone expansion-port cartridge. Use supported player software and the documented audio output; do not install it on an MMC Replay.

Protovision says MP3@64 is no longer available or supported. It is intended for the discontinued MMC64 or IDE64 V4.1. Do not force it onto an MMC Replay: the official FAQ warns that the mechanical mismatch can cause a short circuit.

Combines an integrated MIDI interface with five cartridge-resident SID music applications for sequencing, synthesis, drums, and low-fidelity sample playback.

For this system (exact model): MSSIAH explicitly supports breadbin and slimline C64 systems in PAL and NTSC. It plugs into the expansion port and includes its own MIDI interface. Sequencer is best used with a 1351 mouse; other applications use the keyboard plus a joystick or paddles.

The official contact page reported MSSIAH in stock on 2026-07-28, and its online order workflow was live. The cartridge and software are one integrated product: its MIDI hardware cannot be used by other applications, no MIDI OUT is provided, and the ROMs are not sold separately. A monitor is effectively required, and saving needs a compatible drive or separate Savyour.

Replaces the circuit board in an original or reproduction NES controller so it works as a Commodore 64 gamepad.

For this system (exact model): The seller and open project explicitly name the Commodore 64. Pins 1 through 4, 6, and 8 provide directions, fire, and ground; the instructions warn builders to trace the cable because conductor colors vary.

AutumnHippo exposed an add-to-cart route with a USD 8 base price on 2026-07-30. The page offers a bare PCB, a kit with a reproduction case, and a fully assembled controller, but it does not expose every option price in extracted text. A bare-board build needs a case, a correctly traced cable, a switch or solder bridge, and basic soldering. The maker also states generic Amiga and Atari computer compatibility, but exact model relationships are not attached without model-specific evidence.

Current flashable C64 freezer and development cartridge compatible with Retro Replay, Action Replay, and Nordic Power ROMs.

For this system (exact model): The current shop explicitly names the C64. The otherwise-identical Retro Replay hardware was tested across early, cost-reduced, PAL, and NTSC C64 revisions. Insert the cartridge and any accessory only with power off, then select the documented ROM bank and flash-mode jumpers.

individual Computers marked Nordic Replay available for immediate delivery on 2026-07-30 as a fully assembled and boxed cartridge with the Retro Replay ROM pre-flashed. iComp supports the hardware but not the third-party ROM software. Action Replay compatibility does not supply an Action Replay ROM license; the maker says an owner may use an image from an original cartridge. The accessory connector is documented only for compatible devices such as Silversurfer, RR-Net, and MP3@64, and the technical page warns that incorrectly fitted hardware can short and destroy both devices.

Converts two Wii Nunchuk or NES and SNES Classic Mini controllers into the two Commodore 64 control-port inputs.

For this system (exact model): The adapter uses both control ports and translates two supported Nintendo extension controllers into C64 digital and analog inputs. Check the project's tested-controller list before assuming an arbitrary clone or wireless receiver will work.

Sordan exposed a current Buy route at EUR 30.99 excluding VAT on 2026-07-30. The maker also publishes KiCad files, Gerbers, firmware, assembly instructions, printable cases, and a GPL-3.0 license, and invites direct contact for DIY kits. Controllers and wireless receivers are separate. The guide's acrylic-case tile is an enclosure accessory and is folded into this hardware family.

Replaces many 24-, 28-, 32-, and 40-pin EPROMs and mask ROMs with a configurable RP2350 board programmed over USB.

For this system (exact model): The official project explicitly lists the Commodore 64 as supported and tested. Match the board and firmware configuration to the ROM socket being replaced; ROM images are not supplied.

OneROM boards do not include ROM contents. Supply legally obtained images, choose the correct 24-, 28-, 32-, or 40-pin hardware, configure the exact ROM type and chip-select behavior, and confirm socket clearance and orientation. The open project provides a fabrication path. On 2026-07-24 JCM listed Fire 24, Fire 28, Fire 32, and Fire 40 as kit or assembled options, but its extracted page still called the 32- and 40-pin versions coming soon and did not establish which options could actually be ordered.

Replaces a 24-pin 2364 ROM with a programmable 27xxx-family EPROM or EEPROM and optionally switches among several ROM images.

For this system (exact model): The open project tested the adapter as a C64 KERNAL replacement on Assy 250425. Confirm the motherboard and ROM socket, program 8 KB images at the documented offsets, and wire any bank-select switches correctly.

The Atari-specific Brewing Academy page exposed an Add to Cart path on 2026-07-24, and the open design includes fabrication files. The assembled adapter is configured for a 2764; other capacities need the documented resistor configuration and optional switches. The open project says only the W27C512 configuration was thoroughly tested. Supply legally obtained, exactly sized ROM images and verify socket orientation.

Open PCB that exposes every Commodore 1530 Datassette connector line for Tapuino builds and cassette-port adapters.

For this system (exact model): The C64-named project breaks out every Commodore 1530 Datassette connector line and is intended mainly for Tapuino development. A bare PCB is not a tape emulator; supply and wire the remaining electronics and verify connector orientation before power-up.

The repository provides the KiCad board, schematic, footprint, and documentation files and invites builders to fabricate the open hardware. PCBWay currently offers the 26.92 by 26.03 mm V2 design as a 1.6 mm, two-layer bare PCB and labels that shared project CC BY-SA 3.0. No connector, Mini-DIN lead, enclosure, Tapuino electronics, buffering, isolation, fusing, or current limiting is included or documented. Review the manufacturing files and wiring before ordering and connect hardware only with power off.

Tested period 6510 and 8500 processors for repairing a Commodore 64 with an original CPU.

For this system (exact model): Retroleum explicitly sells both processors for the C64. It says the 8500 was used mainly in the C64C but also works in breadbin systems. Match the installed package and orientation. A socketed CPU can be exchanged directly; a soldered CPU requires safe desoldering and a suitable socket.

Retroleum listed several tested 6510 and 8500 variants with stock on 2026-07-30, but the store was temporarily closed until approximately the beginning of August. These are finite harvested period parts. Confirm that ordering has resumed, whether the selected chip was socket-pulled or desoldered, its pin condition, and the return terms.

Tested period 6526, 6526A, and 6526B interface chips for repairing either CIA position in a Commodore 64.

For this system (exact model): Retroleum tests the chips in both C64 U1 and U2 positions and says 6526, 6526A, and 6526B types make no difference in C64 and C64C use. Swapping two socketed CIAs can help isolate a fault but is not a complete diagnosis. A soldered device requires safe desoldering and a suitable socket.

Retroleum listed tested original CIA variants with stock on 2026-07-30, but the store was temporarily closed until approximately the beginning of August. These are finite harvested period parts. Confirm that ordering has resumed, the pin and test condition of the selected part, and the return terms.

Period original SID chips restore authentic 6581 or 8580 sound when matched to the computer's motherboard voltage and filter circuit.

For this system (exact model): The seller identifies the 12 V 6581 for longboard breadbin systems and the 9 V 8580R5 for shortboard C64C or C64 MKII systems. Match the exact board, supply voltage, filter components, and chip orientation before installation.

AMI64 offered soak-tested original 6581 and 8580R5 chips from GBP 97 on 2026-07-28. These are finite period parts even when a dealer has stock. Confirm authenticity, revision, test history, socket condition, motherboard voltage, filter components, and return terms. Installing a 9 V 8580 in a 12 V 6581 board can destroy it.

Open internal video-overlay module that displays expansion status and other configured messages over C64 composite or S-Video output.

For this system (exact model): The design is primarily documented for showing the state of internal C64 expansions such as MixSID and Reprom64. It accepts composite or amplified S-Video luma from the C64 A/V circuitry and requires custom internal signal, power, and input wiring.

The maker offered assembly kits by email for 25 EUR including regular worldwide mail on 2026-07-30, with a limit of two per person. Stock is kept when practical, but prepaid production batches can take several weeks. The kit includes the PCB, a preprogrammed ATmega, and board components, but not the computer-specific wiring. C64 installation is an advanced internal modification: use amplified luma from A/V pin 1 for S-Video or composite from pin 4, never the unamplified VIC-II luma signal. Driving both outputs requires an expert RF-modulator connection, and excessive overlay brightness can disrupt sync.

A compact inline MOSFET protector that disconnects a Commodore 64 supply when the monitored voltage exceeds the safe range.

For this system (exact model): Every current seller explicitly limits this inline OVP64 to the Commodore 64. Install it between the supply and computer only with power off. A red LED means that the protector has disconnected the supply; do not continue using a supply that has produced an over-voltage event.

Shareware Plus and Ami64 each listed the inline OVP64 at GBP 39 in 2026. Protovision listed six units at EUR 48 with a one-to-two-week shipping estimate on 2026-07-30. All three describe the same compact MOSFET design and a 5.40 V safety threshold. The public listings do not specify a response-time measurement, reset procedure, 9 VAC behavior, current rating, fuse, schematic, or designer. An older boxed OVP64 was sold by Shareware Plus, but its electrical relationship to the current inline product is not established.

Cycle-exact Commodore 1541 disk-drive emulation using a Raspberry Pi and SD-card disk images.

For this system (exact model): The official project explicitly supports the C64. The seller's Hat uses the Option B split-IEC-line configuration and calls for a Raspberry Pi 3. Connect or disconnect the serial cable only while the computer is powered off.

Retro Electronics listed one assembled Option B Pi1541 Hat in stock on 2026-07-25. The Hat is the only supplied part; add a supported Raspberry Pi, SD card, serial cable, legal drive ROM, quality USB cable, and at least a 2.5 A power supply. The official project does not support Raspberry Pi 4 or 5.

Provides laser-cut transparent acrylic housings for original C64 motherboards and Ultimate64 replacement-board builds.

For this system (exact model): The full-size branch is explicitly tested with C64 Assy 250425, 250466, and 250469 motherboards and any original C64 keyboard. The seller says it likely fits all C64 motherboards, but only the named assemblies are verified. The compact branches are only for Ultimate64, Ultimate64 Elite, or Ultimate64 Elite II boards; choose the exact board-specific case. Motherboard and keyboard are not included.

AMI64 listed every verified Plexilaser branch out of stock on 2026-07-30. The full-size C64 case was listed from GBP 100, and both compact Ultimate64 branches were listed from GBP 105. The C64 housing takes about 30 minutes to assemble and supports custom vent text. The older Ultimate64 and Ultimate64 Elite case has optional plug-in LED lighting and is physically distinct from the Elite II case. The Elite II version adds USB and SD-card cutouts, takes about 60 minutes to assemble, and has one reported MechBoard64 fit failure.

Converts composite or S-Video from a C64 or C128 to selectable-resolution analog VGA output.

For this system (exact model): The review tested a C64C over S-Video and reports composite support for older C64s. Image artifacts varied by machine, so confirm return options when buying used and prefer a cable with correct C64 chroma attenuation.

The exact Portta scaler was documented in a 2016 hands-on review, but no current maker product page or stable new-stock source was verified in 2026. The unit includes a short USB-A power cable but no power supply or computer-specific video cable. Results varied by computer: the reviewed flat C128 looked excellent over S-Video, a C64C showed vertical banding and a rainbow border, and a C128DCR produced poor S-Video but good composite output.

A compact semiconductor protector for the 5 VDC and 9 VAC rails of compatible Commodore power supplies.

For this system (exact model): The seller explicitly supports all C64 models with the standard seven-pin version. Install or remove it only with power off. A red LED and extinguished green LED indicate that protection has operated; replace the failed supply rather than repeatedly replacing the protector's fuse.

CMD Marketplace listed four units at USD 40 on 2026-07-30. The page claims a 20 microsecond semiconductor response versus 200 milliseconds for a relay design. After a 5 V trip, its 1.25 A SMD fuse must be replaced with a soldering iron; one spare is supposed to be included. The page simultaneously displayed a USD 9 United States rate and a notice that the item does not ship to the United States, so confirm destination availability before ordering.

Replaces the failure-prone linear 5 V regulator board inside two original Commodore 64 wedge power supplies.

For this system (exact model): The manual supports only the beige wedge-shaped C64 supplies with Commodore part numbers 902503-06 and 902503-11. Do not infer compatibility from enclosure shape alone. This is work inside mains-connected equipment: disconnect the supply, have a qualified person perform the modification, and measure both 5 V output and polarity before connecting the C64.

The Tindie page listed PowerUP! 64W PRO V2 at USD 29 on 2026-07-30, but ordering was paused while the seller takes a break through July 31, 2026. Confirm that sales have resumed and that the seller will ship to the destination. The current V2 listing says it is delivered at 5.15 V; the linked Version 1.0 manual instead documents a 5.2 V default and 5.05-5.25 V adjustment range, so follow the instructions supplied with the purchased hardware rather than assuming the older manual's calibration value.

Compact cartridge-port prototyping PCB and breadboard-bridge kit for C64 hardware development.

For this system (exact model): Both retained pages explicitly name the C64. The kit includes the PCB, a header strip, and a 20 cm male-to-male Dupont cable for breadboard development. Verify every signal, orientation, jumper, and power connection before applying power; no buffering, isolation, fusing, or current limit is documented.

Both email-order pages were last updated on 2025-01-01. The kit page then claimed stock, while the version 2 page gave no price or stock quantity. Neither page exposes a checkout route, pin map, schematic, design files, license, board-revision comparison, protection details, or complete included-parts list for a bare version 2 board. Confirm current availability and the exact PCB revision and package before ordering.

Combines push-button Commodore 64 control-port selection with a dial-adjustable autofire rate.

For this system (exact model): The current product title and description explicitly identify the Commodore 64. No C128, SX-64, mouse, paddle, or two-button-controller support is inferred.

The maker's store exposed an add-to-cart route at a USD 29.99 sale price, reduced from USD 39.99, on 2026-07-30. The public description identifies the C64 but does not publish broader host compatibility, complete signal handling, or an installation manual.

Open four-port Commodore IEC hub with a switch that can hide each attached branch from bus attention.

For this system (exact model): The documented build and user discussion are specifically for Commodore 64 IEC peripherals. It can select between drives that share a device number, but the original board isolates only ATN.

Retro 8bit Shop showed one new unit in stock on 2026-07-27, while the Eagle design remains open for DIY builds. This original design switches only ATN, not every IEC signal; disabled devices remain electrically connected to CLK, DATA, and RESET and can still load or disturb the bus. The acrylic case is an accessory folded into this hardware family.

C64 user-port interface and software for capturing images from a 1997 parallel-port Connectix QuickCam.

For this system (exact model): The seller explicitly identifies a parallel interface for the C64 user port and supplies C64 software on 5.25-inch disk. No C128 or SX-64 relationship is claimed.

Shareware Plus marked both the QuickSCAN interface and a complete Connectix QuickCam package in stock in July 2026. Orders and current pricing require email contact. The camera is a rare 1997 parallel model; do not assume a later USB QuickCam is compatible with the supplied interface or software.

Uses a Raspberry Pi cartridge to emulate up to 16 MB of REU memory or up to 4 MB of GeoRAM-compatible memory on a C64 or C128.

For this system (exact model): The maker tested PAL and NTSC C64 systems. Use a Raspberry Pi 3A+, 3B+, or Zero 2 and a FAT32 microSD card. External Raspberry Pi power is strongly recommended; never power the Pi from both the computer and an external supply at the same time, and boot RAD before the C64.

Retrobit listed five assembled cartridge boards with cases at PLN 93.50 on 2026-07-27. A Raspberry Pi Zero 2 W and microSD card are not included. The upstream project describes RAD as a playground for new features and documents machine-dependent timing and power limitations.

Custom replacement supplies ranging from simple C64 units to multi-connector systems for several Commodore computers and drives.

For this system (exact model): The preserved feature explicitly covers the C64 and C64C. P64 is a C64-only example, while P64-128 and several metal models can be ordered with C64 and C128 connectors. A plastic P64-128 powers only one computer at a time; some metal custom systems can power multiple devices simultaneously. Confirm the exact unit, output ratings, connector wiring, and cable arrangement before use.

The readable C64 OS feature was last modified in September 2022 and gave a USD 35-100 range for standard examples, with more elaborate custom builds possible. It directed orders and inquiries to Ray Carlsen by email. Both linked maker pages failed Tavily extraction and failed again after the required 60-second retry under WF-066 and WF-067, so current ordering, prices, model names, electrical ratings, protection, and mains options must be confirmed directly. Do not transfer the specifications or simultaneous-device behavior of one custom build to another.

Converts NTSC composite video and analog audio from an Apple II or Apple III to an HDMI display.

For this system (bus/interface): Use an NTSC C64 composite-video cable; S-Video is not accepted. ReActiveMicro does not name or test the C64, so this relationship is based on the documented NTSC composite input and the C64 OS guide's Commodore-oriented listing. PAL use is untested.

The adapter was in stock and backorderable for $45 on 2026-07-30. It was not tested or intended for PAL systems. Simultaneously connecting a CRT and this adapter requires a composite impedance-matched switch box or video may degrade or disappear. The package includes generic composite, HDMI, audio-adapter, and power cables, but not a computer-specific Commodore A/V cable.

Open FPGA hardware and gateware platform in a DIP-28 package for emulating 6581 and 8580 SID chips.

For this system (exact model): The project describes the board as fully pin-compatible with 6581 and 8580 SID chips and documents additional address pins that may be connected to a C64 for a second SID address.

The official repository provides hardware and gateware, but this bounded pass did not verify a current assembled-product seller.

Current handmade composite, S-Video, SCART, and luma/chroma cable choices for compatible Commodore computers.

For this system (exact model): The seller explicitly lists the C64 and C64C. Five-pin composite and eight-pin composite choices are available; use the eight-pin S-Video or luma/chroma variants only on a later machine that supplies separate luma and chroma.

AMI64 exposed current priced choices on 2026-07-30. The eight-pin S-Video branch includes a 300-ohm chroma resistor. Connector, signal, and display requirements differ between variants: select a five-pin composite lead for an early C64 or VIC-20, and use the eight-pin luma/chroma branches only with a computer and display that expose those separate signals. The seller describes PAL and NTSC use, but the connected display must still accept the computer's regional video standard.

Socketed rotary-switch ROM board sold with either eight C64 KERNALs or a mixed C64 and 1541 diagnostic set.

For this system (exact model): Install only in the matching socket with the computer powered off and observe the marked orientation. The eight-KERNAL version explicitly excludes C64C systems with a combined 16 KB ROM. The mixed set is intended for separate KERNAL, BASIC, and character sockets and does not claim C64C compatibility.

Retro Electronics listed two KERNAL-set boards and three mixed repair-set boards in stock on 2026-07-25. Both arrive preprogrammed. The pages name original and third-party ROM images but do not document their licensing; verify that you are entitled to use every selected image.

Current ZiModem-based Wi-Fi modem for Commodore 64 and 128 BBS access, Hayes commands, and incoming connections.

For this system (exact model): The product and support pages explicitly cover the Commodore 64. The default speed is 1200 baud; use the documented AT command to select 9600 baud when the terminal software supports it.

Retro Rewind accepted orders with a displayed 2-3 day fulfillment estimate on 2026-07-30. Suitable terminal or BBS software is still required.

Open 90-degree cartridge adapter that brings a C64 cartridge upright and can include a reset button.

For this system (exact model): The project and current assembled listing explicitly target the C64. The cartridge's front side must face the computer.

Sordan exposed an assembled C64 unit with a printed case and stand for dispatch in one to three working days on 2026-07-27. The open repository also provides fabrication files and a printable-enclosure link. A completed 2024-2025 seller run offered bare, kit, and assembled versions tested on C64 or C128 systems.

Line-doubles standard-definition composite, S-Video, or component video for modern digital displays with no added latency.

For this system (bus/interface): Use a suitable composite or S-Video cable from the C64 A/V port. Early five-pin C64 boards provide composite but not separate luma and chroma, so they cannot use the S-Video input without a different video modification.

The original RetroTINK-2X is a retired predecessor; the current 2X Pro was orderable for $139.99 on 2026-07-30. It accepts only 240p, 288p, 480i, and 576i and does not accept 480p or higher input. Supply the correct source-system cable, a digital video cable, and a 5 V / 1 A USB power source; a Micro-USB cable is included. RetroTINK warns that composite sources can produce low output and recommends S-Video or component when available.

Adds a switch-selectable 256 KB to 16 MB DMA RAM Expansion Unit compatible with Commodore 1700, 1750, and 1764 software.

For this system (exact model): The maker explicitly supports the C64 and C64C. Switches select capacities from 256 KB through 16 MB for software with smaller REU expectations.

RETRO Innovations exposed an Add to Cart path at $75 on 2026-07-27. A dated 2026-04-29 notice on the product page says red enclosures were temporarily unavailable and orders could take two to three weeks to ship, so confirm the current enclosure and fulfillment state when ordering.

Controls stepper motors from a Commodore 64 user port for CNC and other motion-control projects.

For this system (exact model): The seller explicitly documents a Commodore 64 user-port connection. This is an externally powered motor-control interface, not a general buffered user-port expander. Verify the manual, wiring, fuses, motor type, supply voltage, current limits, grounding, and power-off connection procedure before use.

Shareware Plus still exposes the GBP 29.95 email-order page, which said "Available from stock" when last updated on January 1, 2025. Confirm present stock, postage, documentation, motor requirements, and the external power arrangement before ordering. The page says both that the board controls two stepper motors and that it is "suitable for 4 standard motors"; human review found additional photographs but no specification that resolves the conflict or establishes safe current limits.

Replaces the RF modulator in supported C64 and C128 systems to improve composite and S-Video output and add configurable rear connections.

For this system (exact model): Supports PAL and NTSC C64 systems except original longboard Assy 326298. Installation requires desoldering the original RF modulator and aligning and soldering the replacement. When the optional luma bypass is absent, its internal-luma jumper must be closed or no picture will appear.

The Lectronz page showed four units in stock at USD 34.17 on 2026-07-27. Machine-specific versions and optional luma-bypass parts are selected before ordering. The seller also reported that shipping to the European Union was temporarily unavailable while Australia Post updated its duty systems.

Replaces the C64 RF modulator with composite, optional S-Video, and mono or dual-SID audio connections.

For this system (exact model): The maker specifies C64 short and long RF-modulator footprints and includes the longboard extension. A period comparison identifies Assy 250469 shortboards and Assy 250407 or 250425 longboards as examples. Verify the actual footprint and pin-1 voltage because installation differs by board.

The official store listed RFOUT! at 22 EUR but out of stock on 2026-07-30. It provides a composite socket, a 3.5 mm audio jack, and solder points for an optional S-Video connector; stereo output requires a dual-SID source and the SJ1 setting. Installation requires desoldering the original modulator. Measure the motherboard supply before installation: boards carrying 12 VDC or 9 VAC on pin 1 require that pin to be removed and a separate 5 VDC connection supplied to RFOUT!. Confirm the footprint, voltage, extension-board fit, and case height before soldering.

Adds wired Ethernet to a C64 either as a direct cartridge or through the clockport of supported carrier hardware.

For this system (exact model): RR-Net MK3 can plug directly into the C64 expansion port without an earlier carrier cartridge. It can alternatively use the clockport of supported MMC or Replay hardware and Turbo Chameleon 64. The IDE64 clockport is electrically compatible but mechanically incompatible.

Current orderability was not established on 2026-07-30. Protovision still labels RR-Net MK3 as current hardware, but its linked product page now returns Product not found, the maker wiki links only to generic shop and reseller pages, and human review could not load a current purchase page. Treat availability as unknown and check the used market.

Hosts USB HID mice, keyboards, joysticks, and gamepads on classic Amigas, with more limited C64 and Atari ST modes.

For this system (exact model): AMIGAstore explicitly says C64 use requires additional adapters and a firmware update and does not support mouse mode. Treat this as a USB joystick or pad path on the C64, not as the USB mouse adapter implied by the buyer's-guide heading.

Amiga Shop listed Rys MKII in stock at EUR 44.95 with a 3-4 day shipping estimate on 2026-07-30; AMIGAstore separately listed EUR 31.95 but out of stock with restock T.B.A. Retro 7-bit publishes current Amiga firmware 0.16, manual 1.5, Windows flashing software, and RysWheel installers. Seller claims conflict about wireless mice, so buyers should assume a wired supported HID device unless Retro 7-bit confirms a specific receiver.

A historical relay protector with alternate DC and AC inputs for several Commodore power configurations.

For this system (exact model): The maker explicitly names C64, C64C, C64G, C64GS, and Aldi variants and rates the design for up to 3 A. A trip opens both DC and AC output paths. Confirm an acquired unit's trip setting, cable condition, and connector wiring before use.

The surviving Round 4 sale thread is explicitly titled SOLD and dates to 2017. It offered complete kits at USD 45 and assembled units at USD 85. C64 OS repeated those prices in 2022, but that does not establish later production. The former hookturn.com user-guide URL now resolves to a parked domain. Use the preserved feature and forum specifications for identification, and search the used market rather than contacting the old seller as though stock were current.

Adds SCSI disk hardware to a Commodore 64 through a CS/A adapter, with experimental external IEC-drive variants.

For this system (exact model): The verified path is a C64 CS/A expansion adapter combined with the separate CS/A SCSI card. The one-board C64 layout is unverified. External IEC variants mention C64, C128, and VIC-20 use but lack complete-system test evidence, so those machines are not attached to this record.

Only the modular C64 CS/A adapter plus CS/A SCSI card combination is reported tested and working. The simplified combined C64 board was not fully checked. VC-SCSI 1.0's component boards were tested separately but not as a complete drive, VC-SCSI 1.x remained an idea, and VC-SCSI 2.x was preliminary and untested. The published FAT12/FAT16 filesystem software is explicitly early beta and may corrupt a disk; never test it with valuable media. No current kit or assembled seller was verified.

Retired family of SD-backed SCSI drive emulators that includes internal 50-pin and direct-attach DB-25 hardware.

For this system (bus/interface): SCSI2SD v5.1 can replace the internal 50-pin SCSI hard-drive mechanism in an existing CMD HD used with a C64. It does not connect directly to the C64, and migration requires the CMD controller, power, configuration, and a partition backup and restore plan.

Upstream describes SCSI2SD V5 and V6 as permanently retired. SamplerZone nevertheless exposed an Add to Cart path for a cased v5.5 at $129.95 on 2026-07-27, including configured microSD media and optional HD50 or Centronics-50 adapters. Treat v5.1 as a used-market mechanism upgrade and confirm reseller fulfillment for v5.5. The documentation hub lists v4.8.4 from 2019 as the latest firmware for both versions. V5.5 has fixed termination and must be last on its chain; hosts without DB-25 termination power need USB power.

Family of IEC storage devices that lets supported Commodore computers access files and disk images on SD or other removable media.

For this system (exact model): Many external, internal, and DIY variants explicitly support the C64. A Retro Electronics internal board requires correctly wiring 5 V, ground, IEC clock, data, and attention lines; incorrect wiring can damage both the computer and SD2IEC.

Retro Lemon listed its user-port-powered C64, C128, VIC-20, and SX-64 variant in stock at GBP 34.17 on 2026-07-27, and Sordan exposed a current Buy now path for its combined SD2IEC and Tapecart variant. PolyPlay's plain external Sordan Micro device and Retro Electronics' internal board were out of stock, while the RetroFletch backplane seller was on a break. A complete open C64 SD2IEC LP hardware build is also available. Variant power, connectors, controls, and firmware configuration differ. The official firmware site says 0.x firmware is obsolete and warns that newer-dated bootloaders are not necessarily safer or better.

Safely connects a Sega Mega Drive or Genesis controller to a Commodore 64, Commodore 128, or Amiga with configurable fire and jump mappings.

For this system (exact model): All three sources explicitly name the C64 and address the Sega controller's incompatible electrical behavior. Follow the powered-selector warnings and the mapping directions for the chosen variant.

The open CERN OHL 1.2 project supplies design and fabrication files plus a bare-PCB ordering route. On 2026-07-30, Gotek Retro listed its assembled C64/128 and Amiga adapter at EUR 15 and AMI64 listed its assembled C64 and Amiga adapter at GBP 20. Turn the computer off before changing selectors, choose the correct computer mode, and assign each function only once. The open and AMI64 versions may need a joystick extension cable at an Amiga 600.

Assembly kit that adds a numeric track or sector display to supported Commodore floppy drives.

For this system (bus/interface): The current retail package is for 1541 and 1541-II drives used with the C64. The board installs inside the drive, not the computer, and requires assembly plus a display mounting plan.

Commodore4ever and Protovision both exposed current-priced product pages on 2026-07-27, but neither extraction exposed an unambiguous Add to Cart control. Confirm availability before ordering. The kit requires through-hole assembly, display wiring, and internal drive installation; stacked boards or sockets can create clearance problems.

Adds 512 KB of bank-switched geoRAM-compatible cartridge memory to a Commodore 64 or 128.

For this system (exact model): The maker says the cartridge plugs into a Commodore 64 cartridge port and adds 512 KB. Use geoRAM-aware software; Commodore 1750 and 1764 REU software is not automatically compatible.

The Shareware Plus page was updated on 2026-01-01 and says the cartridge is in stock by email order. Protovision also maintains a current product listing, but its extracted page does not expose a stock or checkout control. This is geoRAM memory, not an REU; software must explicitly support the geoRAM interface.

Replaces the C64 RF-modulator circuitry while retaining composite and S-Video through the computer's A/V port.

For this system (exact model): The maker's visually rendered list names PAL and NTSC Assy 250407 boards. An independent review also tested a SixtyClone Assy 250466. No other C64 revision is claimed here; confirm the exact motherboard before invasive installation.

The current maker page remains online but exposes no price, stock state, or order control. Human inspection recovered a maker compatibility list naming PAL and NTSC Assy 250407 C64 boards and all C128 board revisions; Tavily did not render those list values. A 2020 independent review also tested a SixtyClone Assy 250466, where both composite and S-Video worked. Removing the original modulator and installing Shuriken requires desoldering and soldering. RF output is removed.

Cartridge-port second-SID family represented by current SID Symphony reproductions and a selectable-address 6581 SID Cart.

For this system (exact model): Both current variants explicitly support the C64 or C64C. The ToTs reproduction includes an ARMSID, while the Shareware Plus board requires a user-supplied 6581. Stereo software must address the second device at a location supported by the selected cartridge.

ToTs RETRO listed its ARMSID-equipped CMD reproduction as made to order on 2026-07-28. Shareware Plus also advertises its chip-less 6581 SID Cart from stock, but that page was last updated in January 2025; confirm that variant before ordering.

Partially assembled internal board for adding a second matching SID chip at $DE00 or $DF00.

For this system (exact model): The current manual covers a standard C64 installation. A soldered original SID must first be desoldered and socketed. Never mix 6581 and 8580 chips; incorrect socket alignment or voltage configuration can destroy them. Boards 250407 and 250469 can have tight keyboard clearance.

The MSSIAH availability page reported the SID2SID circuit board in stock on 2026-07-28, and its order workflow includes SID2SID. SID chips, audio wiring, and an output jack are excluded. Shareware Plus separately advertises a parts pack without the PCB or SID chips while its remaining stock lasts.

Uses a Raspberry Pi cartridge to emulate memory, sound, cartridges, ROMs, and file-loading functions across several Commodore 8-bit systems.

For this system (exact model): Tested on PAL and NTSC C64 systems, Ultimate64, and C64 Reloaded boards. A Raspberry Pi 3A+, 3B+, or Zero 2 is supported. KERNAL replacement and SID emulation require wires to CPU pin 28 and SID pin 8. Boot the externally powered Pi first, and never power it from the computer and an external supply simultaneously.

The open project publishes Gerbers, BOMs, software, and case files for full-size and Zero boards. Retro-Updates' assembled Sidekick64 Zero was out of stock on 2026-07-27 and excludes the Raspberry Pi Zero 2. The maker calls the project a personal playground and warns that unsupported images, timing glitches, and unsafe cartridge combinations remain possible.

Adds one or two original SID chips with automatic model detection, selectable mono or stereo addressing, protected power, and a dedicated stereo output.

For this system (exact model): The maker lists C64 and C64C boards 326298, 250407, 250425, 250466, and 250469. Some revisions have prerequisites in the installation manual. The unit needs one or two user-supplied SID chips and its supplied cables for switches, stereo audio, and stereo addressing.

The official site reported the SIDFX bundle sold out on 2026-07-27 and says no more modules will be manufactured after its limited stock is exhausted. The separate C64 Reloaded MK1 and MK2 adapters are accessories for this same family and do not replace the unavailable SIDFX module.

DIY RP2040- or RP235x-based replacement for one or two 6581 or 8580 SID chips, with optional FM emulation and paddle or mouse input support.

For this system (exact model): The project explicitly describes SIDKick Pico as a drop-in 6581 or 8580 replacement for the C64. It can emulate two SIDs or one SID plus FM, but audio routing differs by hardware variant and firmware.

Choose the hardware design and matching firmware together. The official project documents different DAC, PWM, connector, line-output, and host-interface arrangements plus a list of preassembled sellers. Multi-SID or FM modes need the documented address-signal wires. Never power the module from USB and the Commodore computer at the same time.

Internally powered user-port adapter family for connecting a Commodore 64 or 128 to DE9 RS-232 equipment.

For this system (exact model): The standard version operates through 2400 baud. The C64-UP9600 version can reach 9600 baud with compatible software, although Simulant recommends 4800 baud for better reliability with its Retro Wifi SI setup.

The product page marked the adapter out of stock on 2026-07-30. Grey, black, and white enclosures and the two speed configurations remain one functional product family. The modem, passive DB25 converter, and serial or null-modem cables are separate.

Bare replica motherboards for rebuilding damaged Commodore 64 boards in four original assembly configurations.

For this system (exact model): Choose the replica that matches the intended C64 component set: 250407, 250466, 250469 Rev. A, or 250469 Rev. B. The long-board and short-board revisions require different RAM, ROM, PLA, SID, VIC-II, CPU, clock, and logic parts. This is an advanced board-level rebuild, not a drop-in populated replacement; verify the selected BOM and every donor or modern substitute before assembly.

Bob's Bits listed the bare SixtyClone PCB at USD 35 on 2026-07-30 with live revision and optional-component controls. The Tindie page simultaneously displayed a United States shipping rate and a does-not-ship warning, so confirm destination availability before ordering. Resistor, capacitor, resistor-network, power-switch, SwinSID Nano b, and GAL-PLA options do not make the base board a complete computer.

Open ROM adapter that selects alternate C64 KERNALs through the RESTORE key and indicates the active bank with an LED.

For this system (exact model): Choose the board from the motherboard assembly number, not the case: longboard 326298, 250407, 250425, and 250466 use one version, while shortboard 250469 uses the other. Installation requires a socketed ROM plus soldered RESTORE, RESET, and optional EXROM wiring. The shortboard image must include BASIC in each 16 KB bank.

The open project provides Gerbers, firmware, and programming guidance. Retro Electronics lists an assembled board, cables, LED, and blank 27C256 or W27C512, but its page did not expose a current stock or ordering state on 2026-07-25. Users must program legally obtained ROM images; the seller specifically notes that JiffyDOS and JaffyDOS require licenses.

Historical MOS 8701 replacement with automatic PAL or NTSC selection and an onboard switchable oscillator.

For this system (exact model): The maker explicitly lists Assy 250425, 250466, and 250469 plus C64 Reloaded MK1. The normal configuration automatically follows the motherboard PAL or NTSC jumper; solder bridges can instead force one standard. Older Assy 326298, 250407, and KU-14194 boards are not listed.

The maker's August 2021 AmiBay thread said that only a few units remained, and the thread is now closed. No current direct order path was verified. Inspect a used board for its solder-bridge configuration before relying on automatic motherboard selection.

Connects a Super Nintendo controller to the user port of supported Commodore computers for software written to read its serial protocol.

For this system (exact model): The seller explicitly names the C64. Use software written for the adapter, such as Attack of the PETSCII Robots or another listed compatible title.

TexElec listed the adapter at USD 14.99 and in stock with backordering enabled on 2026-07-30. Most supported machines use the supplied power jumper. Some PET systems do not provide user-port power and need 5 V from the cassette port or an external source; high-current third-party controllers should also use external power because the user port is rated for 100 mA.

Converts a Super Nintendo controller into Atari-style direction and fire signals for tested Commodore, Amiga, and Atari computers.

For this system (exact model): The maker tested both PAL and NTSC C64 systems. The default mapping uses A or B for fire, while alternate mappings and autofire are selected from the SNES controller.

This is a build project rather than a current assembled product. Use the published Atari/Commodore wiring, ground PB1 to select that mode, and program the ATmega8A with the documented firmware and fuse bytes. The maker reports successful tests on a C64, Amiga 500, Amiga 600, and Atari 130XE; the 130XE relationship is banked because that exact target is not yet in the catalog. Minimig and Amiga CD32 are explicitly unsupported.

Internal stereo SID card sold for several C64-family computers with a connection cable and configuration jumper.

For this system (exact model): The seller explicitly lists the Commodore 64 and 64C. The package includes the stereo card, connection cable, jumper, and stickers, but the public page does not identify supported motherboard revisions or explain installation.

poly.play and human review reported the card out of stock on 2026-07-28. HR-056 found no additional public setup information, so confirm the required SID chips, addressing, voltage configuration, and installation procedure before obtaining old stock.

User-port Wi-Fi modem for connecting a Commodore 64 or 128 to Internet BBS services.

For this system (exact model): The seller explicitly supports the C64 through its user port. Load CCGMS or other suitable terminal software using a TapeCart, Pi1541, SD2IEC, or equivalent device.

Retro Electronics listed two assembled modems in stock on 2026-07-25. The ESP8266 is flashed and configured, but terminal software and the separate device needed to load it are not supplied.

Adds a live track, density, write-protect, motor, and sync display to supported Commodore floppy drives.

For this system (bus/interface): Install the tracker in a supported 1540, 1541, 1541-II, or 1571 drive, not in the C64. The 1541-II and 1571 require the special 6522-included version and direct soldering.

The standard and 6522-included variants were both out of stock on 2026-07-24. The 1541-II and 1571 require the special version with a 6522 VIA soldered to the tracker board; the standard version will not work in those drives. Installation can require desoldering the original VIA, fitting a socket, and mounting the display and button externally.

Discontinued C64C RF-modulator replacement with rear-panel S-Video and 3.5 mm audio jacks.

For this system (exact model): The surviving hands-on review says the tested board fits only the C64 Version E Assy 250469 shortboard and demonstrates installation on Assy 250469 Rev. 4. Do not assume it fits a C64 longboard or another Super VIDEO revision.

The original maker site is gone, and a 2020 discussion describes the closed design as dead. An independent review tested an older version on an Assy 250469 Rev. 4 C64C: the first board was faulty, the replacement worked, CRT S-Video improved slightly, flat-panel results were worse, and composite output was unusable in that setup. A later eBay version once claimed C64C and C128D support plus an AEC fix, but no surviving manual or seller page establishes its exact differences or safe C128 installation. Buy used only with a return option and exact revision documentation.

Installs inside supported Commodore floppy drives to duplicate protected disks and add disk utilities.

For this system (bus/interface): The board installs in a supported 1541-family or 1571 disk drive, not in the C64 itself. Match the Supercard+ variant to the exact drive model; some installations require desoldering the drive's 6502.

Both assembled variants were out of stock on 2026-07-24. Each listing includes a 40-pin socket and version 6.0 software on two 5.25-inch disks. Some drives require desoldering the 6502 and installing a socket, so identify the drive model and board revision before ordering or installing.

Replaces a C64 or SX-64 KERNAL ROM with 36 selectable ROM or program slots, file browsing, firmware updates, and optional WLAN and FTP access.

For this system (exact model): Use the 24-pin assembly for original breadbin KERNAL ROMs such as 901227 and the 28-pin assembly for C64C or C64G combined ROMs such as 251913. The module needs a compatible socket or careful desoldering and socket installation. Select the documented jumpers and orientation for the exact package, and adjust PLA timing only when necessary.

No current official retailer or reproducible fabrication package was verified. A July 2026 hobby report says units had reappeared on Kleinanzeigen, so treat SuperKernal as used-market hardware and verify that the module, WLAN board, headers, firmware, and documentation are included. Supply only ROM images you are licensed to use.

Connects as many as eight standard SNES controllers to a Commodore 64 or 128 through its two control ports.

For this system (exact model): The adapter occupies both control ports and supports as many as eight ordinary SNES controllers. Software must implement the SuperPad64 or ninja SNES serial scan; an ordinary one-player joystick routine cannot read it.

Poly.play listed the adapter at EUR 45 but marked it out of stock on 2026-07-30. Controllers are separate; the store's current third-party SNES pad is a commodity accessory and remains folded into this record. Poly.play's short description incorrectly says user port, while the linked original wiring document and C64 OS technical explanation both say that SuperPad64 occupies the two control ports and leaves the user port free. Confirm the supplied connector arrangement with the seller before ordering a future production run.

Configurable replacement for failed 82S100-based Commodore PLA chips, with documented modes for selected C64, 264-series, PET, CBM-II, and 1551 hardware.

For this system (exact model): Official support is limited to Assy 326298, 250407, 250425, and 250466 at U17, plus the original C64 Reloaded board at U17. The shipped C64 setting uses jumpers 1 and 4. Assy 250469 and the C128 are not listed. Power off and unplug the computer, confirm the board number and socket, and do not force or bend the adapter pins.

Individual Computers' main product index, last modified in May 2026, lists SuperPLA V4 as a spare part while placing the older SuperPLA and V3 under Sold out. The current shop root also exposes a Super PLA V4 product image, but Tavily did not expose an exact product-specific cart or stock control on 2026-07-30. Confirm current orderability before buying. The underside jumpers and adapter pins are very small; use the official mode diagram, tweezers, bright light, and careful handling.

Captures audio into a Commodore 64 and plays recordings back in 8-bit digital sound with DigiMaster software.

For this system (exact model): The seller and release pages explicitly name the Commodore 64. The documented package pairs the hardware with DigiMaster software; confirm that the software, instructions, and required audio cable are present before buying a used unit.

Shareware Plus said in April 2026 that it no longer sells the SUX 6400 and suggested looking on eBay. The surviving pages do not provide a complete manual, connector description, or detailed recording limits, so inspect any used package carefully.

Host-specific C64 and C128 breakouts with open eight-pin designs plus an assembled five-pin option for early C64 boards.

For this system (exact model): The open C64 board and current eight-pin builds expose composite and S-Video through standard sockets. For the early Assy 326298 five-pin A/V port, Commodore4ever sells Sven Petersen's separate assembly with composite video, audio input, and duplicated mono audio. That version does not claim S-Video.

Retro Rewind listed the assembled eight-pin C64 version, while Commodore4ever listed both eight-pin and early five-pin C64 versions on 2026-07-30. The open eight-pin C64 and dedicated C128 variants remain buildable from board, BOM, and case files. The standard C64 board physically blocks the IEC port on a C128, so use the dedicated C128 layout there. Optional two-channel output requires a second SID or similar source wired to pin 7; otherwise both output channels carry the computer's mono audio.

Open five-board set for bringing Commodore cassette, user-port, and PET IEEE-488 connections to headers and ribbon cables.

For this system (exact model): The repository explicitly names the C64 for the cassette breakout and the user-port output arrangement. Select the computer-facing output board, matching breakout, and correct six- or 26-conductor cable; the five boards are not interchangeable.

The public repository provides revisioned PCB project files, pictures, and a GPLv3 license, but no current assembled seller is documented. Builders must fabricate the required board pair, fit connectors, and make the matching ribbon cable. The concise README does not document buffering, isolation, fusing, current limits, or a safe live-connection procedure; verify orientation and wiring and make every connection with the computer powered off.

Adds an internal SwiftLink-compatible ESP8266 Wi-Fi modem to supported Commodore 64 longboards and Commodore 128DCR systems.

For this system (exact model): The maker limits this form to non-short-board or longboard C64 systems and reports tests on 250407 and 250466 boards. It fits under U2 and requires the original 6526 CIA, a dot-clock lead, and address selection at DE00 or an optional D700 decoder.

The assembled Tindie listing was retired by 2026-07-30. The open project retains Eagle design files, firmware, patches, and installation material. This is a board-specific internal installation that requires removing and reusing a 6526 CIA plus routing flying leads; verify the motherboard revision and instructions before fitting it.

Current Lotharek redesign of the compact AVR-based replacement for a Commodore 64 SID sound chip.

For this system (exact model): The reconstructed firmware project describes SwinSID as an economical way to restore C64 sound. It lacks paddle inputs and external SID audio input, and an independent 2024 test found very strong digital aliasing in its 6581 configuration. Compare it with newer replacements and obtain seller-specific switch and orientation instructions before fitting it.

The Lotharek page exposed a login-or-register-to-buy path on 2026-07-27. The independent nano SwinSIDb tutorial documents the reference design's settings: its J1 selects 6581 filtering when closed and 8580 when open, while J2 enables an output-load resistor for 8580 boards and is left open for 6581 boards. It also says the design lacks paddle analog inputs and external audio input. The seller does not state that its dual DIP switch maps identically, so obtain Lotharek-specific switch and orientation instructions before installation. The latest firmware identified by the tutorial is dated 2012; original development stalled, and the reconstructed archive warns that one unreleased firmware can glitch.

Period enhanced SwinSID replacement adds configurable 6581- and 8580-style sound, readable oscillator and envelope registers, analog input, and paddle or mouse support.

For this system (exact model): The maker's manual describes installation in every C64 board revision and documents the board jumpers, 5 V-only power, 6581-board output change, EXT IN termination, default settings, and software configuration. Verify orientation and board-specific setup before applying power.

Production ended in 2018 and no current maker or build path was verified. Buy used only with the original manual and configuration software. The documented 6581-board installation recommends disconnecting the 1K output pull-down, while EXT IN needs the specified termination. This is unrelated to current Commodore 64 Ultimate hardware despite the old product name.

Adds a DE10-Nano Linux coprocessor, 1080p HDMI video, DMA, storage, networking, and a framebuffer overlay to a Commodore 64.

For this system (exact model): Current support covers PAL and newer 65-cycle NTSC C64 systems. Old 64-cycle NTSC, Drean, C64 Reloaded MK2, and Commodore 64 Ultimate systems are explicitly unsupported. Installation also requires three wires from CPU pins 27, 28, and 29 to the carrier. Passthrough cartridges require SYSOP-64 I/O to be disabled, and the maker reports that some EasyFlash 3 software remains sensitive.

The project remains under construction and its current releases are alpha previews. Carrier Gerbers, a BOM, placement data, and preview releases are available, but a DE10-Nano or compatible MisterPi board and the supplied SD image are also required. Change the default Debian root password before connecting it to a network.

Cassette-port microSD loader for launching C64 TCRT and PRG files through an on-screen browser.

For this system (exact model): Connect the unit directly to the C64 cassette port with its LEDs facing up. Reversed insertion can damage the Tapecart SD or computer. Put the browser program in the root of a FAT32 microSD card to select TCRT and PRG files.

Retro Electronics listed four assembled units with printed cases in stock on 2026-07-25. A FAT32-formatted microSD card is required and is not included.

Arduino-based SD-card datasette emulator family for Commodore cassette ports, with TAP writing on the Mini variant.

For this system (exact model): Both seller variants explicitly support the C64 through its cassette port. The full-size unit provides playback; the Mini reads and writes TAP files. Power the computer off before inserting or removing either device.

Retro Electronics listed one full-size Tapuino and two Tapuino Mini units in stock on 2026-07-27. An SD card is not included, and the required C16/Plus/4 cassette-port adapter is excluded.

A source-available relay board that cuts the C64's 5 V supply above about 5.6 V.

For this system (exact model): The project is designed for the C64 and may be built as an external inline box or an internal modification. Use Revision E or apply the documented C/D DIN-pin correction, fit the specified fast fuse, verify every connector and conductor with power off, and electrically test the finished unit before connecting a computer.

The public repository was last updated in January 2020 and PCBWay retains a bare-board order route for Revision E. No explicit hardware license is published, so this is source-available rather than licensed open hardware. Revisions C and D require a documented bridge between DIN pins 4 and 5 for supplies that place 5 V on the alternate pin; Revision E incorporates that fix. A separate builder found severe thermal drift in an older Console5-derived prototype and called that build unfit for protection. Test any completed board's trip point and stability under realistic load and temperature before relying on it.

Combines ROM and program loading, MIDI, Ethernet, NFC launching, remote control, a real-time clock, and REU functions in a Teensy 4.1 cartridge.

For this system (exact model): Validated on NTSC and PAL C64 and C64C systems. Early Assy 326298 boards have a reset-circuit issue that must be corrected before TeensyROM or other fast-load cartridges will work reliably.

The maker's Lectronz store showed six fully assembled revision 0.4 units at USD 64.00 on 2026-07-27. The programmed Teensy 4.1 and case are included. A CR1225 battery is included only with United States shipments, and an SD card or USB drive is needed for content beyond the built-in files.

Adapts a USB mouse or digital USB joypad to supported Amiga, Atari ST and STE, or Commodore 64 GEOS mouse ports.

For this system (exact model): The page provides a Commodore 64 GEOS 1351-mouse-emulation mode. Select that mode during startup and confirm the intended software expects a 1351-compatible mouse.

The product page exposed a login-or-register-to-buy path on 2026-07-27. Only digital joypad input is supported; analog controls are not. TIKUS is distinct from the visually similar, non-upgradable Tank Mouse Kickstarter adapter. The revision sold since 2026-03-24 adds stored per-axis sensitivity configuration for Amiga and Atari mouse modes.

Historical low-power MOS 8701 replacement with separate PAL and NTSC versions and an onboard oscillator.

For this system (exact model): The maker names Assy 250425, 250466, and 250469 plus the original C64 Reloaded MK1. Separate PAL and NTSC boards were offered. The thread does not establish a finished adapter for older Assy 326298, 250407, or KU-14194 boards, which do not use the same socketed 8701 arrangement.

The original AmiBay sales thread is closed and its seller account has been deleted. No current direct order path was verified. TOLB was sold in separate PAL and NTSC versions, so identify the fitted variant and motherboard video standard before installing a used unit.

Connects USB HID mice, keyboards, joysticks, and gamepads to Commodore, Amiga, and Atari ST-family control ports.

For this system (exact model): Rev3 has a C64 mode that emulates a 1351 mouse and also translates supported HID controllers. Sordan labels mouse use as GEOS-only, and the manual requires an extension cable. Connect the DB9 side only while the C64 is powered off.

Sordan hosts current Rev3 and Micro Tom pages and a Rev3 manual, but neither product page exposed a price, stock value, or product-specific cart route on 2026-07-30. AMI64 listed TOM 2+ at GBP 40 but out of stock. TOM+ and TOM Rev2 are retained as older variants rather than presumed current products. USB peripherals may be hot-plugged, but the DB9 adapter must be connected only while the old computer is powered off. Device compatibility is not universal.

A modified SNES-style controller with a nine-pin Commodore plug and a software-read serial button protocol.

For this system (exact model): Connects to a normal control port, but it is not a drop-in ordinary joystick. Software must clock and read the SNES serial button stream. Trap Them and the Joyride controller utility support it.

Poly.play listed the stand-alone controller at EUR 15 and the game-and-controller edition at EUR 35, but both were out of stock on 2026-07-30. The linked Poly.play technical wiki returned 404 and then returned the same 404 after the required 60-second retry; the dead URL is recorded in the research registry.

Combines a C64 accelerator, VGA output, REU and GeoRAM memory, SD storage, dual 1541 emulation, input adapters, and cartridge emulation in one FPGA cartridge.

For this system (exact model): Cartridge mode supports European PAL-G and newer 65-cycle NTSC-M C64 systems. Old 64-cycle NTSC and Drean PAL-N machines are unsupported. Do not connect it to a C128 or C128D: Individual Computers warns that doing so can damage both devices. The Datasette port cannot be used while the Chameleon is connected.

Individual Computers listed Turbo Chameleon V2 out of stock at EUR 235.44 on 2026-07-27. The official firmware remains in beta, with current releases and known bugs maintained in the product wiki. A CR1220 battery, networking card, docking station, cables, power supply, keyboard, and monitor are not included unless separately stated.

Cassette-port interfaces that load tape audio from a phone, tablet, or other player into supported Commodore computers.

For this system (exact model): The current uCassette page explicitly lists the C64. Supply an audio source with a 3.5 mm output and use cassette-image audio that the computer and loader can read.

AMI64 exposed an active Add to Cart listing on 2026-07-27. The page documents audio playback into the computer but does not claim that this interface can record or save tape output.

Replaces a Commodore 64 motherboard with an FPGA-based board offering modern video, storage, networking, and emulated peripheral functions.

For this system (exact model): This replaces the C64 motherboard and requires a compatible case and C64 keyboard. The official setup guide also calls for C64 ROM images; original SID chips are optional.

The official store still listed the Ultimate64 Elite-II out of stock on 2026-07-27. Its home page says the black short-board run is sold out and Commodore has taken over sales of its version of the board. Check both current vendors rather than assuming another 1541 Ultimate batch.

Adds USB-backed disk-image storage, drive emulation, networking, and other emulated peripherals to Commodore 64 and 128 systems.

For this system (exact model): The official quick guide identifies the Ultimate-II+ as a cartridge and storage solution for the Commodore 64. Network functions are provided by its own firmware rather than RR-Net compatibility.

The official store showed several Ultimate-II+L color variants in stock on 2026-07-15, with some colors on back order. On 2026-07-27 its home page said new orders include the Wi-Fi module, but it also retained an outdated February 2026 restock notice; verify the selected variant before ordering.

Adds firmware-controlled RGB lighting inside a C64 case fitted with an Ultimate64 mainboard.

For this system (bus/interface): This relationship applies only to a C64 case fitted with a 1541 Ultimate Ultimate64 or Ultimate64 Elite mainboard. Hardware revision 1.4 and later provides dedicated P8; earlier boards use documented user-port-header pins. It is not an accessory for a stock C64 motherboard, and compatibility with the newer Commodore 64 Ultimate is not established.

Official construction and pinout documentation and multiple printable mounts remained downloadable on 2026-07-30. COREi64's assembled shop is closed for updates until Fall 2026, so no current prewired retail kit is claimed. Use firmware 1.10 or later and the exact 5 V wiring. The official guide warns that shorting 5 V to ground can burn a board component and applying 5 V to an FPGA pin can damage the FPGA.

Brings an Ultimate64 replacement board's internal user-port header to a C64-style edge connector with the power rails needed by compatible peripherals.

For this system (exact model): This applies only when the C64 case contains a 1541 Ultimate Ultimate64 or Ultimate64 Elite replacement mainboard. It connects to that board's internal 26-pin header, not the exposed edge connector on an original C64 motherboard. Observe the keyed orientation and current limits in the official documentation, and connect or disconnect only with power off.

The 1541 Ultimate store listed version 2.0 for EUR 9.98 but out of stock on 2026-07-30. The flat cable is included. The official documentation warns that the connector has only one correct orientation: its red wire must align with pin 1, and a shifted or reversed connection can damage the board or accessory. The header's extra pins can drive either 9 VAC generation or an APA102C LED strip; the documentation says 9 VAC is enabled when LED-strip use is off. Do not assume this earlier Ultimate64 adapter is interchangeable with Commodore's separate C64U User Port Adapter.

Experimental C64 replacement motherboard with three SID sockets, optional internal storage and sound modules, ROM switching, and extensive test points.

For this system (exact model): This replaces the motherboard and fits a C64 case; it does not modify an existing original board. Complete READY+ with compatible CPU, VIC-II, CIA, PLA, SID, and ROM parts, and use the specified 12 VDC 2 A supply. The maker requires installation and commissioning by qualified personnel, a nonconductive operating surface, and suitable shielding.

On 2026-07-30, UNI64 listed the bare v4 PCB at EUR 32.50 as a three-week preorder and the READY+ board at EUR 345 with a five-week order lead time. READY+ includes standard logic, the 8701, and 64 KB RAM but excludes all named Commodore-specific chips and the required 12 VDC 2 A supply with a 2.1 mm inner-diameter barrel plug. Optional Pi1541, MIDI, FM OPL2, and SSD hardware is not included. The bare page labels its feature list as Version 3 even though the product and files are v4; the linked v4 info PDF remained unreadable after the required retry under WF-071, so confirm version-specific assembly details from the supplied documentation.

Connects modern Bluetooth gamepads and, on selected models, mice to Commodore, Amiga, and Atari computers.

For this system (exact model): The active C64 layout is designed to fit the C64 and C64C without extension cables. It supports additional C64 button protocols and rumble, but games must explicitly understand those nonstandard features; paddle firmware remains work in progress.

The official C64, A500, and 800XL Tindie pages were out of stock on 2026-07-30, although the project marks those models active and supported. CBMretro had equivalent cased C64/C128 and A500/A1200 hardware available at EUR 41.90; the original designer does not support third-party builds. Open hardware, firmware, and documentation remain available. The guide's original Unijoysticle tile is folded here as the retired WiFi predecessor: it needed a separately powered ESP8266 receiver and phone or desktop client, unlike the Bluetooth successor.

Provides a menu-driven utility cartridge or a bare board for building a custom multi-EPROM C64 cartridge.

For this system (exact model): The complete cartridge plugs into the C64 expansion port. A bare board requires compatible EPROMs, a user-created image, programming, assembly, and an optional case.

The complete new-old-stock cartridge was out of stock, but bare genuine boards were in stock on 2026-07-24. A bare board includes no case or EPROMs. Building a custom cartridge also requires legally sourced Promos or Promenade Menu Maker software, which CBMSTUFF cannot distribute, plus EPROM programming and assembly.

Open EPROM cartridge board for making single-ROM, switchable multi-ROM, and diagnostic cartridges for the C64 and C128.

For this system (exact model): The project explicitly targets C64 cartridge development. The supplied quick guide covers generic 8 KB, 16 KB, and Ultimax images plus switch-selectable combinations; builders must match jumpers, switches, EPROM layout, and image type.

The repository provides board revisions, fabrication files, and documentation. A working cartridge still requires a PCB, components, a correctly programmed EPROM, and configuration appropriate to the selected ROM images.

Replaces a breadbin C64 VIC-II with an FPGA implementation offering configurable video, extra VRAM, new graphics modes, and optional digital or RGB output.

For this system (exact model): The current design replaces 6567 and 6569 chips on Assy 250407, 326298, 250425, and KU-14194HB motherboards. It does not replace 8562 or 8565 chips used by most C64C shortboards. Large-board digital or RGB use can require RF-shield and RF-modulator removal. Its micro-HDMI connector carries nonstandard-timing DVI rather than HDMI audio, and some displays will not sync or provide a 4:3 mode.

Official distributor VideoGamePerfection offered Mini and Large boards for EUR 74.95 to EUR 103.95 with an Add to cart path on 2026-07-27. The maker warns that some Large boards shipped by VGP with firmware 1.17 contain a DVI-instability bug and should be reflashed with the corrected 1.17 image.

Open internal C64 modification that switches between installed PAL and NTSC VIC-II chips and includes LumaFix64 video cleanup.

For this system (exact model): The current instructions explicitly support breadbin Assy 250407, 250425, and 250466 motherboards. They explicitly exclude slimline C64C cases, SX-64, and C128 systems. Any revision of the required 6567 and 6569 VIC-II chips may be used.

The current project page provides build files, component links, PCB ordering routes, and a video guide under CC BY-NC-SA 4.0. This is not a plug-and-play board: installation removes the RF shielding, desolders motherboard parts and jumpers, adds pins, and requires both a 6567 and 6569 VIC-II. The connected display must accept both PAL and NTSC or one switch position may produce monochrome video or no usable picture. The authors provide no warranty or installation support.

DIY Commodore 64 wireless-interface project built around a MicroView display.

For this system (exact model): The repository identifies the project as a WiFi Cart for the Commodore 64 with MicroView. No broader Commodore compatibility is claimed here.

The project files remain downloadable, but no current assembled seller was verified. The readable top-level project material does not specify the computer connector, supported online services, transfer speed, or complete present-day parts requirements, so builders should inspect the repository before committing to a build.

Adds Wi-Fi BBS and Hayes-modem access through the user port of supported Commodore computers.

For this system (exact model): The standard WiModem plugs into the C64 user port with its components facing upward. It supports 75 to 230400 baud, although terminal software often imposes a lower limit.

The standard display-free version and both PET versions were out of stock on 2026-07-30. The standard OLED page still said a new design was pending and did not offer ordering. Check the direct pages for a restock or revised design.

Open cartridge-port expander with three independently controlled positions, configurable bus signals, and a reset switch.

For this system (exact model): The maker explicitly lists the C64 and C64C. Compatible cartridges can be selected or combined, but their address use, signal loading, and power behavior must not conflict.

The official store exposed an active $30 listing on 2026-07-27, and the open Eagle files remain available. Cartridge combinations are not guaranteed, the two connectors at the third position share one set of switches, and the passive bus can worsen marginal signal integrity. Insert, remove, and configure hardware only with the computer powered off.

Compact SwinSID-derived 6581 or 8580 replacement with hardware mode selection and a higher audio-output level.

For this system (exact model): The seller documents installation in the C64 U18 socket and selection between 6581 and 8580 behavior. Confirm module orientation and motherboard voltage before fitting it; paddles and the 1351 mouse are unsupported.

Tindie showed 10 units in stock at USD 38.88 on 2026-07-28, while AMI64 listed the same family at GBP 49. Tindie's extracted page gave contradictory US shipping information, so confirm destination eligibility before ordering. X-SID does not support paddles or a mouse, and neither seller publishes technical, firmware, or installation documentation.

Bridges a modern computer over USB serial to Commodore IEEE-488 and IEC equipment, or supplies host-backed storage to a Commodore computer.

For this system (exact model): The project explicitly supports the C64 through serial IEC, using a modern PC as backing storage with XD2031. Confirm the cable and host software, and correct the documented board-connector footprint problem.

The maintainer explicitly calls XS1541 orphaned and reconstructed its documentation from an archived build guide. The surviving page provides a schematic, firmware, and detailed assembly and flashing steps, but not a turnkey current kit. The original board connector footprints are buggy: the narrow connector can short contacts unless the coding gap is physically corrected. A build also requires fine-pitch FT232RL soldering, ATmega programming, fuse setup, cables, and suitable host software.

Adds push-button or controller-triggered port swapping plus four selectable autofire rates to a Commodore 64.

For this system (exact model): The seller explicitly specifies the C64. The adapter occupies both control ports, supplies 5 V on both external sockets, and swaps digital plus pins 5 and 9 analog signals.

Tindie showed two units in stock at USD 34 on 2026-07-30. Remote swapping requires modifying a controller with two diodes and a button, or rewiring an existing button. Mouse operation is only an untested seller expectation; the documented analog support covers paddles, gamepads, and two-button joysticks.