Tag: user port

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

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.

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

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.

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

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.

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

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.

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

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

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.

Brings the Commodore 64 Ultimate's internal user-port header to an edge connector for user-port peripherals.

The direct Commodore listing was out of stock on 2026-07-27. The connecting cable is included. The seller documents this only for the Commodore 64 Ultimate, whose user-port header is internal; an original C64 already has an external user-port edge connector and does not need this adapter.

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

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.

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.

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

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.

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

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.

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

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.

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

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.

DIY diagnostic ROM and loopback harness for PAL and NTSC Commodore 264-family computers.

Rob Clarke's current download directory offered Diag264 0.97 on 2026-07-30. The maker also offers a programmed EPROM at media and postage cost by email. The software is CC BY-NC-ND 4.0: unmodified personal distribution with attribution is allowed, but modification and commercial resale are prohibited. The maker warns that some third-party marketplace copies were unauthorized or modified. Loopback hardware may be resold when the attribution conditions are met.

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

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.

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

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.

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

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.

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.

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.

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

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.

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

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.

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

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.

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

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.

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

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.

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

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.

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

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.

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

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.

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

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.

Tests a VIC-20's keyboard, IEC, user, cassette, and joystick interfaces with a machine-specific cartridge and loopback harness.

AMI64 listed its GBP 47 complete cartridge-and-harness kit as available in around ten days on 2026-07-30. CMD Marketplace listed three USD 59.90 PAL/NTSC kits, but its Tindie page exposed conflicting United States shipping text and no usable US rate. Sven Petersen publishes the GPLv3 hardware and firmware project.

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

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.