Atari 600XL upgrades

A compact 16 KB XL-series Atari 8-bit computer with SIO and parallel-bus expansion.

Also called: 600 XL

At a glance

Introduced: 1983

Products listed: 61

Exact-model evidence: 19

Family/interface evidence: 42

Upgrade types: 13

Vintage searches: 2

Upgrade directory: 600XL

Browse everything below, or filter by product type, availability, and compatibility basis. Notes explain whether evidence names an exact target, a broader family, or only the relevant bus or interface for this computer.

Showing 61 products.

StatusProductWhat it doesLinks
DiscontinuedChecked Jul 27, 20261050E Floppy Drive Turboby Lotharek

Upgrades an Atari 1050 disk drive for divisor-6 high speed, 180 KB per side, and flashable firmware slots.

For this system (bus/interface): This modifies an external Atari 1050 SIO drive rather than the computer. Confirm normal drive and SIO operation before installation and use host software that supports the selected high-speed and density modes.

Lotharek marks 1050E discontinued. The seller calls installation solderless, but it still requires opening the drive, removing three chips, moving the 6507 CPU, and preserving socket orientation. Confirm that a used kit is complete, that all original chips and sockets are healthy, and that suitable 1050E firmware and host software are available.

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AvailableChecked Jul 27, 20265cfab 1064Mby 5cfab

Raises an Atari 600XL from 16 KB to 64 KB with a compact external parallel-bus module.

For this system (exact model): This is an exact 600XL upgrade that plugs into the rear parallel bus, raises the factory 16 KB configuration to 64 KB, and draws power from the computer.

The page reported four modules in stock on 2026-07-27. The 600XL supplies the required 5 V through its parallel bus, so this exact module needs no external power supply.

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AvailableChecked Jul 27, 20265cfab 1090XL 320K Memory Cardby 5cfab

Provides 64 KB of main RAM and 256 KB of RAMBO-compatible extended memory through a 1090XL-family expansion slot.

For this system (bus/interface): Use through a compatible 1090XL-family expansion system. The card raises the host to 64 KB of main RAM plus 256 KB of RAMBO-compatible extended memory; check its PBI-memory jumper against any VBXE or Ultimate 1MB installation.

The page reported three cards in stock on 2026-07-27. A 1090XL or 1091XL base system is required and is not included. The PBI-memory option must remain off when the host has VBXE or Ultimate 1MB. The RAM-disable option is recommended for modern reproduction systems so other cards can map their own memory.

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AvailableChecked Jul 27, 20265cfab 1090XL 80-Column RPP Cardby 5cfab

Provides 80-column text over HDMI from a Raspberry Pi Pico card installed in a 1090XL-family expansion system.

For this system (bus/interface): Use through a compatible 1090XL-family expansion system. The card replaces normal video while enabled and is limited to text software using Atari operating-system input and output.

The page reported three cards in stock on 2026-07-27. A 1090XL or 1091XL base system and a separate HDMI display are required. Enabling the card disables normal video output; holding Shift while booting disables the card. Each installed expansion card needs its own jumper-selected device ID.

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AvailableChecked Jul 27, 20265cfab 1090XL CX-85 Interfaceby 5cfab

Connects an Atari CX-85 numeric keypad through a 1090XL-family expansion slot with an onboard input handler.

For this system (bus/interface): Use through a compatible 1090XL-family expansion system with a separate CX-85 keypad. The onboard handler is documented only for software using Atari operating-system input and output.

The page reported two cards in stock on 2026-07-27. A 1090XL or 1091XL base system and an Atari CX-85 keypad are required. Current compatibility is limited to software that obtains input through the Atari operating system.

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AvailableChecked Jul 27, 20265cfab 1090XL Modernized Reproductionby 5cfab

Adds five 1090XL-family expansion slots to an Atari 600XL or 800XL through the rear parallel bus.

For this system (exact model): The seller explicitly supports the 600XL through its rear parallel bus. Use the supplied 50-pin cable and provide the separate 9 VAC Atari power supply.

The page reported one system in stock on 2026-07-27. The 50-pin parallel cable is included, but a compatible 9 VAC Atari power supply is not. Expansion cards and the optional 12 V supply configuration cost extra; the seller says no currently available card needs that optional 12 V rail. Systems are assembled on demand and may take several days to ship.

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AvailableChecked Jul 27, 20265cfab 1090XL OS Extension Cardby 5cfab

Adds Hias high-speed SIO and Fast Math F+ through a 1090XL-family expansion card.

For this system (bus/interface): Use through a compatible 1090XL-family expansion system. High-speed SIO still requires a compatible peripheral such as a suitably upgraded 1050 drive.

The page reported two cards in stock on 2026-07-27. The sale includes only this card; the 1090XL-family base system and the separately pictured CP/M card are not included.

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AvailableChecked Jul 27, 20265cfab 1090XL Z80 CP/M Cardby 5cfab

Adds an 8 MHz-or-faster Z80, 64 KB of onboard memory, and a beta CP/M environment through a 1090XL expansion slot.

For this system (bus/interface): Use through a compatible 1090XL-family expansion system. The Z80 card supplies its own 64 KB, but the host still needs the base system, storage, and beta CP/M software.

The page reported one card in stock on 2026-07-27. CP/M customization and utilities remain late beta. The card is sold with or without a Z80; a user-supplied CPU must be rated for at least 8 MHz. The pictured 80-column RPP card is optional and not included. Double-density disk use also requires supporting drive hardware. The exact page names only the 1090XL, so confirm 1091XL compatibility before using it in that implementation.

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AvailableChecked Jul 27, 20265cfab 320K XL Memory Upgradeby 5cfab

Expands an Atari 600XL or 800XL to 320 KB through the rear parallel bus without opening the computer.

For this system (exact model): The seller explicitly supports the 600XL and says it powers this module through the rear parallel bus without an external supply.

The Tindie page reported one unit in stock on 2026-07-27. A 600XL supplies power through its parallel bus. Most 800XL computers do not, so the board provides a jumper-selectable USB-C or wired 5 V input. Follow the seller's internal-versus-external power procedure and jumper setting for the exact computer.

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AvailableChecked Jul 27, 2026A8PicoCartby Robin Edwards

Loads cartridge images and XEX files from USB-managed flash storage through an inexpensive RP2040-based Atari XL/XE cartridge.

For this system (exact model): The current seller explicitly lists the Atari 600XL, and the project supplies an XL/XE cased PCB orientation. Never connect USB while the cartridge is inserted in the Atari. DIY builds require the specified purple USB-C Pico clone; the official green Raspberry Pi Pico has different pin functions and may damage both devices.

A8Renegade's live Shopify product data and collection reported the assembled cartridge orderable on 2026-07-27, despite a contradictory sold-out label in the rendered product page. The complete open design also remains buildable.

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AvailableChecked Jul 27, 2026ACID STEREOby Lotharek / AcidMaker

Retains the original POKEY while adding FPGA stereo POKEYs, Covox channels, digital mixing, and a high-rate stereo DAC.

For this system (stated family): The seller states that ACID STEREO supports all Atari 8-bit systems. It requires the original POKEY and at least stereo-output wiring; the second POKEY, Covox, and full mixing stages require additional model-specific connections.

The product exposed a login-or-register-to-buy path on 2026-07-27. It requires a working original POKEY and can be installed in stages: basic stereo output, a second POKEY through an A4 connection, Covox through D6xx or D7xx decoding, and full internal-audio mixing. The approximately 1 mm PCB intentionally leaves pin 31 unconnected; verify that it remains isolated from the motherboard. Only the basic stage uses a single address jumper, while the expanded functions require additional signal and audio wiring.

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AvailableChecked Jul 25, 2026APE Warp+ OS 32-in-1by Atarimax

Replaces the Atari XL or XE operating-system ROM with a switchless 32-image OS selector and high-speed SIO features.

For this system (stated family): The product page describes the generic kit for all Atari XL and XE computers except XEGS. Atarimax does not publish a separate 600XL guide on the product page, so confirm motherboard socketing, clearance, and the exact installation procedure before ordering or modifying the computer.

The official page showed self-installation and professional-installation options in stock on 2026-07-25. The generic kit is for XL and XE computers except XEGS; the special 1200XL kit includes an XE MMU and internal BASIC upgrade. The 1200XL procedure is an advanced modification that can require desoldering and replacing ROM sockets, moving jumpers, adding wires and a resistor, and modifying or omitting the RF shield.

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AvailableChecked Jul 27, 2026Atari AV Breakoutby A8Renegade

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 600XL but says S-video requires both a monitor port and a chroma modification. The page does not supply modification instructions; verify the exact motherboard and video wiring before use.

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.

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Build itChecked Jul 27, 2026Atari Real Clock (ARC)by Pasiu / SSG and Qcyk / Dial

Adds a battery-backed real-time clock to Atari XL and XE computers as an internal module, pass-through cartridge, or circuit inside another cartridge.

For this system (stated family): The project is designed for Atari XL and XE computers. An internal installation needs the documented bus signals and D5xx decode connection; a cartridge form needs suitable pass-through hardware.

The project page publishes a parts list, clock and address-decoder schematics, battery and rechargeable-cell backup circuits, and an ARC handler archive. It recommends internal installation because the pass-through and inside-another-cartridge forms may cause more problems. The page does not provide a step-by-step bus-wiring guide: an internal build must source D0-D3, A0-A7, R/W, phase 2, power, and D5xx cartridge-control signals, while a cartridge build uses the cartridge connector. No explicit project license or current assembled seller was verified.

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Find usedChecked Jul 27, 2026Atari XF551 Disk Driveby Atari

Period SIO floppy drive adds double-sided, double-density 5.25-inch storage and faster double-density transfers to Atari 8-bit computers.

For this system (stated family): Atari describes the XF551 as an XL and XE storage device connected through the computer's Peripheral SIO port. Full double-sided, double-density use requires software beyond the bundled DOS 2.5.

Find a complete used drive with the correct AC adapter and SIO cable. The bundled DOS 2.5 supports single and enhanced density but not the XF551's full double-sided, double-density capacity; use DOS XE or compatible third-party software for that mode. Most drives use a Mitsumi mechanism with a rectangular activity LED, while later Chinon examples have a round LED and stricter flippy-disk limitations. The 300 RPM mechanism can also conflict with a small amount of speed-sensitive copy protection.

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AvailableChecked Jul 27, 2026Atarimax Maxflash Systemby Atarimax

Provides blank flash cartridges and a USB programmer for building reusable Atari 8-bit multicarts.

For this system (stated family): Atarimax explicitly describes the Maxflash system for Atari 400, 800, XL, and XE computers. The cartridge is used in the Atari while the separate USB programmer and Maxflash Studio prepare its contents on a modern computer.

The official page showed the cartridges and USB programmer in stock on 2026-07-25. These are blank programmable products and do not include commercial ROM images. Unplug the programmer before attaching a cartridge, verify label-side-up orientation, and connect directly to the PC rather than through a USB hub for first-time use. Backwards insertion can damage both the cartridge and programmer.

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AvailableChecked Jul 25, 2026Atarimax MyIDE-IIby Atarimax

Adds CompactFlash storage, cartridge-image loading, and onboard flash and SRAM to Atari XL and XE computers.

For this system (stated family): Atarimax describes MyIDE-II for the Atari XL and XE family through the cartridge port. Confirm CompactFlash preparation and software requirements before use.

The official page showed MyIDE-II cartridges and accessories available on 2026-07-25. A prepared CompactFlash card is offered separately, so confirm the selected package contents. No ROM images are included; users must supply legal images and software.

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AvailableChecked Jul 27, 2026Atarimax SIO2PC/ProSystem Interfaceby Atarimax

Connects Atari 8-bit SIO computers and disk drives to a modern host for peripheral emulation and disk transfer.

For this system (bus/interface): The interface works with Atari 8-bit computers through SIO. USB versions are intended for Atarimax APE on Windows, while the RS-232 version is compatible with SIO2PC software available for several host operating systems. Confirm the required SIO cable and chain position.

The official page showed USB and RS-232 ordering options on 2026-07-25. Select the interface and connector arrangement for the intended host software and SIO chain. An Atari SIO cable and the computer or disk-drive hardware needed by the chosen workflow are not included. The USB setup documentation is dated and lists Windows 95 through Windows 7, so confirm current host support rather than assuming modern Windows compatibility.

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AvailableChecked Jul 25, 2026Atarimax/ABBUC USB Cartridgeby ABBUC e.V. and Atarimax

Adds a two-port USB host interface for supported keyboards, controllers, mice, and other driver-backed devices.

For this system (stated family): Atarimax explicitly describes the cartridge for all Atari 8-bit computers. Confirm that a MicroUSB driver exists for the exact USB device and Atari software workflow you intend to use.

Atarimax marked the cartridge in stock and ready for shipment on 2026-07-25, although the same page called the current price a preorder promotion through 2026-07-31. This is not a generic plug-and-play USB port: support depends on Atari-side drivers. Atarimax still describes the software as early beta, and the MicroUSB project's substantive status notes are historical, so check the device matrix and exact driver before buying hardware for a particular peripheral.

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Build itChecked Jul 27, 2026Don Neff 600XL 64K Upgradeby Don Neff / Michigan Atari Magazine

Expands a 16 KB Atari 600XL to 64 KB with two 41464 DRAMs and three wiring changes.

For this system (exact model): The guide is specifically for converting a stock 16 KB Atari 600XL to 64 KB by replacing U11 and U12 and changing the RAM and address wiring.

The archived instructions call for two 41464-10 or compatible DRAMs, hookup wire, soldering tools, and optional sockets. Chips may need desoldering, several pins and resistor leads must be isolated, and fine motherboard traces are exposed; the author explicitly says to attempt it only if the diagram is understood and at the builder's risk. This is a historical modification guide, not a current kit.

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AvailableChecked Jul 27, 2026FujiNetby FujiNet project

Adds Wi-Fi networking and platform-specific peripheral emulation to several vintage computer families.

For this system (stated family): The official project supports the Atari 8-bit family with platform-specific SIO hardware. Confirm the exact FujiNet enclosure, power path, firmware, and SIO connection for the 600XL.

JCM showed 16 Apple II base units in stock on 2026-07-24. On 2026-07-27 Lotharek offered its assembled Atari Professional version both alone and with a dedicated SIO cable. It normally takes operating power from Atari SIO and uses USB-C for firmware flashing, although the page separately calls USB-C an optional power source for the 1200XL. The project also lists other small-batch vendors and open design files. Stock, enclosure, connection, power, and required interface hardware vary by computer.

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AvailableChecked Jul 27, 2026GTIA2RGBby Lotharek / AcidMaker

Adds digital RGB, optional 31 kHz scandoubling, display corrections, and an 80-column overlay while retaining the original GTIA.

For this system (stated family): The draft manual supports the entire PAL and NTSC XL/XE family and says its palettes were measured on 600XL and 800XL hardware. Not every model and region combination was tested. Confirm GTIA socket height, update firmware, and use the documented output mode and cable pinout.

The product exposed a login-or-register-to-buy path on 2026-07-27. Update its initial firmware before installation. A socketed GTIA may still require careful removal of the adapter's bottom socket for height; a soldered GTIA must be desoldered. The May 2026 hardware manual is explicitly a draft. The product page publishes a complete VGA pinout but leaves the 15 kHz connection diagram unfinished, so do not improvise a SCART or RGB-monitor cable from that page. SECAM computers use an incompatible FGTIA pinout and are not supported.

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AvailableChecked Jul 27, 2026Happy 1050 Upgradeby Atarimax / 5cfab

Upgrades an Atari 1050 disk drive with true double density, faster backup operations, and protected-disk support.

For this system (bus/interface): This upgrades an external Atari 1050 SIO disk drive rather than the computer itself. The guide covers all Atari 1050 drives and explicitly excludes other drive models; verify that the 1050 and the rest of the SIO chain work normally before installation.

The 5cfab stand-alone Happy Warp 1050 v7.1 reproduction reported two boards in stock on 2026-07-27; Atarimax still provided a conditional add-on route on 2026-07-25. The 5cfab board includes its CPU and needs no soldering, but installation still requires opening the drive and carefully replacing internal hardware. Align the board's crystal with its clearance hole. The Atarimax guide also warns about static, alignment, and orientation.

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AvailableChecked Jul 28, 2026JIL Sammerby Lotharek

Adds an SIO-connected General MIDI file synthesizer with external stereo output and Atari audio mixing.

For this system (bus/interface): The device connects through SIO and supplies separate stereo output. Confirm the required Atari player software, supported MIDI workflow, and monitor-audio behavior for the 600XL.

The product exposed a login-or-register-to-buy path on 2026-07-27. It is a MIDI-file synthesizer, not the MyTek MIDI input/output interface already in the catalog. The public page and human review provide no written player-software, file-workflow, or model-specific SIO-audio instructions. Treat the external stereo output as the documented playback path and confirm software availability before purchase.

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Build itChecked Jul 25, 2026JOY2PICby MyTek and Daniel Serpell

Programs supported PIC microcontrollers from an Atari 8-bit computer through a joystick port.

For this system (stated family): The project uses an Atari 8-bit joystick port and Atari flashing software. Build the programmer, provide the required firmware file, and verify the target PIC and orientation.

Schematics, Gerbers, parts information, Atari software, and bare-PCB order links are public. A build still requires assembly and careful device orientation. Confirm that the exact PIC is supported before programming it; the STIK socket does not support every PIC package or family.

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AvailableChecked Jul 27, 2026JUST_POKEYby Lotharek

Replaces a failed or missing Atari POKEY with an updateable FPGA module in the original DIP-40 socket.

For this system (exact model): The seller explicitly names the Atari 600XL. Installation is a direct swap only when the existing POKEY is socketed; firmware can be updated through the module's built-in USB interface.

The product exposed a login-or-register-to-buy path on 2026-07-27. Installation is solderless only when the computer already has a compatible DIP-40 POKEY socket. This is a functional FPGA replacement, not a transistor-level NMOS clone; the seller warns that software depending on undocumented analog behavior or exact electrical characteristics may behave differently. The built-in USB port allows future firmware updates.

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AvailableChecked Jul 27, 2026Lotharek AKI Keyboard Interface Familyby DarkDK, Andre Bertram, and Lotharek

Adds an internal PS/2 or USB keyboard interface to supported Atari 8-bit computers by interposing at the POKEY socket.

For this system (exact model): The PS/2 page explicitly names the 600XL in its original-keyboard troubleshooting note. Installation interposes at POKEY, adds four control wires, and requires the supplied external keyboard connector; remove R2 and R3 if the original keyboard stops working.

Both variants exposed login-or-register-to-buy paths on 2026-07-27. A non-socketed POKEY must be desoldered, four control wires are required, and installation calls for a new case opening for the supplied keyboard socket or cable. The PS/2 page says an original keyboard that stops working on a 600XL or 800XL requires removal of R2 and R3; XE and XEGS machines leave those resistors intact.

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AvailableChecked Jul 27, 2026Lotharek SIO2PC / 10502PC Familyby Lotharek

Connects Atari SIO computers to a modern USB host, with 10502PC variants that can also image disks through a physical Atari drive.

For this system (bus/interface): All variants connect through a free SIO port. Select DSR or CTS handshaking for the exact adapter and configure the host software before booting; use a 10502PC variant when imaging disks through a physical Atari drive.

The basic SIO2PC USB, 10502PC Revision 2, and USB-C Revision 3 pages all exposed login-or-register-to-buy paths on 2026-07-27. Host emulation requires a modern computer, FTDI serial drivers where needed, and software such as RespeQt or AspeQt. The basic interface's manual uses DSR handshaking, while the 10502PC pages specify CTS for SIO2PC mode. Physical-drive imaging requires a 10502PC variant, ALibPC, and the documented FTDI setup; launching ALibPC changes the adapter to 10502PC mode, and unplugging and reconnecting USB restores its default SIO2PC mode.

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AvailableChecked Jul 27, 2026Lotharek SRAM Replacement Familyby Lotharek

Replaces Atari 8-bit dynamic RAM with modern SRAM or configurable FPGA-managed PSRAM in three current versions.

For this system (exact model): The seller explicitly says all three memory modules upgrade a 600XL to 64 KB. Choose the basic, Lite, or Professional feature set, verify CPU and MMU socketing, and follow the model's CAS_INHIBIT and EXT_SEL wiring.

All three memory variants exposed login-or-register-to-buy paths on 2026-07-27. Installation goes under the CPU and may require removal or isolation of the original DRAM, desoldering, new sockets, and EXT_SEL or CAS_INHIBIT connections. The Professional version also uses an MMU adapter and its page says to install the latest firmware before use. The optional Freddy Module v2 cannot operate alone: the seller requires the basic SRAM module first and says VBXE owners do not need the Freddy replacement.

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AvailableChecked Jul 28, 2026Medusa Rev. Bby AcidMaker / Lotharek

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

For this system (stated family): The current mode list covers Atari XL/XE VBXE RGB, while Medusa's analog decoder also accepts generic composite and S-Video. A 600XL still needs a usable video output or upgrade plus a correctly wired source cable; Medusa does not create a signal that the computer lacks.

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.

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AvailableChecked Jul 30, 2026Micromys V5by individual Computers

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 (stated family): The Atari 8-bit mode defaults to the Atari ST mouse protocol and also offers CX22 trackball, Amiga mouse, joystick, paddle, and Koala Pad modes. Software must support the selected protocol.

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.

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Build itChecked Jul 27, 2026MouseTARIby MyTek

Converts a PS/2 mouse into Atari 8-bit or Atari ST quadrature mouse signals.

For this system (stated family): The project explicitly supports Atari XL computers. An external build can use a joystick-port plug; an internal build requires protected wiring behind the motherboard's in-line resistors.

The maker publishes beta firmware, source, a pinout, and programming files but not a finished adapter PCB on this page. A build requires a programmed PIC16F1847 and suitable wiring or an enclosure. For an internal installation, connect behind the computer's in-line joystick resistors so a plugged-in joystick cannot directly short the PIC outputs. USB mice work only when they also implement the PS/2 protocol.

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AvailableChecked Jul 27, 2026MyIDE and MyIDE+Flash Familyby Sijmen Schouten / Atarimax

Adds IDE hard-disk storage through cartridge, internal flash-OS, and original Atari 800 DIY implementations that predate MyIDE-II.

For this system (stated family): Atarimax sells the predecessor interfaces for XL and XE computers, but the cartridge version requires 64 KB and the stock 600XL has only 16 KB. Expand the computer first and confirm the internal installation path because the official 600XL guide remains listed as forthcoming.

The official Atarimax page said the interfaces were in stock and extended its sale through 2026-07-31 when checked on 2026-07-27; verify that short-lived offer before ordering. The family has been superseded by MyIDE-II but remains functionally distinct because it accepts IDE devices rather than providing MyIDE-II's onboard CompactFlash and FAT32 loader. The cartridge requires a 64 KB XL or XE. Internal installation ranges from an OS-ROM socket plus three signal wires in an 800XL to extensive socket, jumper, MMU, BASIC, and wiring changes in a 1200XL. Mr. Atari's original 800 version is an advanced personal-use DIY design with schematic and firmware files but no complete build instructions or bill of materials.

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Build itChecked Jul 27, 2026MyTek SIO2MIDI Familyby MyTek / The Brewing Academy

Connects MIDI instruments or an optional DreamBlaster wavetable module to an Atari 8-bit computer through SIO.

For this system (stated family): The product page explicitly covers the Atari XL family. Use the SIO2MIDI or SIO2MIDI-S2 variant and provide the required SIO cable plus compatible MIDI hardware or software.

The storefront family was sold out on 2026-07-24, but MyTek publishes schematics, Gerbers, firmware, and bare-PCB order links for SIO2MIDI and SIO2MIDI-S2. SIO2MIDI-S2 does not route its synthesized sound through the Atari; use its headphone or speaker jack. The maker page also includes 1088XEL-only MIDI-XEL variants, which are not attached to factory-computer entries.

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Build itChecked Jul 27, 2026ndary Simple XL Video Modby ndary

Sharpens video on some PAL or NTSC Atari 600XL and 800XL boards by disconnecting one filter capacitor.

For this system (exact model): The exact 600XL instruction is to disconnect C109. It was reported working on PAL or NTSC hardware; do not extrapolate it to SECAM or an unidentified board revision.

The recovered 2017 discussion says to lift or cut one capacitor leg, making later restoration possible, and the author tested PAL and NTSC machines only. SECAM compatibility is unresolved. Several commenters report that later Revision D 800XL boards omit C56 or use a different layout, so identify the exact board revision and component before changing anything. The quoted 80 percent improvement is the author's subjective estimate, not a measured specification; more complete video upgrades may produce better output.

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AvailableChecked Jul 27, 2026O2 Fixerby Piotr D. Kaczorowski / Lotharek

Replaces the 74LS08 clock logic in Atari XL and XE computers with four separately buffered O2 outputs.

For this system (exact model): The page explicitly gives pin 5 as the usual 600XL CPU O2 location, but requires continuity testing because board layouts can differ. Replace the 74LS08 with a socketed O2 Fixer and select capped or uncapped outputs for each load.

The product exposed a login-or-register-to-buy path on 2026-07-27. Installation replaces a 74LS08; a non-socketed chip must be desoldered and the required 14-pin socket is not supplied. The installer must identify the motherboard's actual CPU O2 connection by continuity rather than relying blindly on a model example. Three outputs carry 680 pF capacitors, while the uncapped top output is intended for Ultimate 1MB; remove a corresponding capacitor if a capped output causes instability.

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AvailableChecked Jul 24, 2026Open2327 ROM Adapter Familyby SukkoPera / The Brewing Academy

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

For this system (stated family): The Atari storefront variant is intended to replace the BASIC ROM in Atari XL computers, including use of Revision C BASIC. Confirm that the 24-pin BASIC ROM is socketed; otherwise installation requires desoldering and fitting a socket.

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.

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Build itChecked Jul 27, 2026Original SDrive and SDrive NUXXby C.P.U. and nuxx.net

Emulates writable Atari XL and XE floppy drives from SD storage using the original ATmega8 SDrive design or the NUXX packaging variant.

For this system (stated family): The original project explicitly supports Atari XL and XE computers through SIO. A DIY build needs the ATmega8 hardware, programmed firmware, an SIO connection, and an SD-card setup matched to the selected firmware revision.

The original GPL-3.0 hardware, firmware, Atari-side software, documentation, and source remain public. Its 2009 documentation specifies cards up to 2 GB with FAT16, while the repository also contains a later 2012 SDHC-supporting source revision; match the firmware, media setup, and documentation deliberately. The NUXX archive is frozen as of 2020 and says its function is identical to original SDrive, but adds a different PCB, enclosure, connector options, and optional STK200-style parallel-port programmer. No current assembled seller was verified.

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Build itChecked Jul 27, 2026Pasiu 1 MB SIMM Expansionby Pasiu / SSG

Uses a 1 MB 30-pin SIMM and GAL controller to add switchable Compy Shop or Newell/RAMBO banked memory to Atari XL and XE computers.

For this system (stated family): The project groups the 600XL with the 1200XL and older 800XL delay-line design, but provides no dedicated 600XL installation section. Treat it as an engineering adaptation, not a ready model-specific recipe.

The Polish project page publishes a schematic, GAL JEDEC file, utilities, parts list, full 800XL and Freddie-equipped 800XLF instructions, startup tests, and timing troubleshooting. Installation is highly invasive and may require trace cuts, lifted or bent IC pins, motherboard timing changes, and RAS-delay tuning for a particular machine. The page groups the 600XL and 1200XL with older 800XL memory-control hardware but does not provide separate step-by-step guides for those models. No explicit project license was verified.

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AvailableChecked Jul 27, 2026PWR3 Atari 8-bit Power Supplyby Lotharek / Mean Well

Provides a modern regulated 5 V, 3 A power supply for explicitly supported Atari XL and XE computers.

For this system (exact model): The seller explicitly names the 600XL. Supply the separate country-appropriate mains lead and verify the seven-pin DIN connector is undamaged and correctly oriented before use.

The product exposed a login-or-register-to-buy path on 2026-07-27. It includes the power supply but not the country-specific mains lead. Use only with one of the seller's explicitly named computers and verify connector orientation and mains-cord type before powering the machine.

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Build itChecked Jul 27, 2026SDrive-ARMby Alexey Spirkov (fintros)

Reimplements SDrive around a 48 MHz Cypress PSoC ARM controller with microSD, capacitive controls, eight drives, and cassette emulation.

For this system (stated family): The project describes support for Atari 8-bit systems including XL machines. The version 1.1 hardware adds a diode so the device can work in an SIO chain.

The repository publishes Eagle hardware files, PSoC firmware, update binaries, documentation, and enclosure models. Initial controller programming requires a Cypress KitProg-compatible programmer and the source expects the older PSoC Creator 4.0 toolchain. The latest tagged update is from 2018 and fixes FAT16, large ATR and 256-byte-sector handling, applies Hias patches, and improves SD-card compatibility; the last repository change shown is from 2022. No current assembled seller or explicit repository license was verified.

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Build itChecked Jul 25, 2026SDrive-MAXby KBr

Emulates Atari SIO disk and cassette drives from microSD storage with an Arduino and touchscreen.

For this system (stated family): The project is an Atari 8-bit SIO peripheral. A build needs compatible Arduino and display hardware, a microSD card, firmware programming, an SIO connection, and a safe power arrangement.

The Brewing Academy kit was sold out on 2026-07-24, but the firmware and build files remain public. Its kit still requires assembly and part of an SIO cable. The official project strongly recommends external power because the approximately 150 mA load exceeds the Atari SIO specification; follow its wiring instructions carefully to avoid back-powering the computer or device.

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AvailableChecked Jul 27, 2026SDrive-Simple-II Familyby MyTek, Dropcheck, and Lotharek

Provides open internal and currently assembled external SD-based SIO disk-emulator variants for Atari 8-bit computers.

For this system (stated family): The maker describes SDrive-Simple-II as fitting virtually any factory Atari 8-bit computer above its SIO connector. Confirm internal clearance, SIO wiring, SD access, and firmware programming before assembly.

Lotharek exposed a login-or-register-to-buy path for SD Drive Mini on 2026-07-27, and Retro Lemon also listed it with pricing. It plugs directly into SIO, uses a FAT32 microSD card and SDRIVE.ATR, and provides two buttons plus LEDs for selecting four drive slots. The separate open SDrive-Simple-II build still requires PCB assembly, ATmega328P programming, and an internal SIO connection. Its documented firmware supports cards up to 32 GB and ATR and XEX files, but not CAR, ROM, ATX, XFD, or CAS files, and it has no control for swapping disks in a multi-disk title. The former SDriveXEL assembled source and exact public build package remain unavailable.

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AvailableChecked Jul 27, 2026SIO Splitterby Lotharek / Retro Lemon

Expands one Atari SIO connection into four peripheral ports with optional external power and bus-activity indicators.

For this system (bus/interface): The seller specifies Atari 8-bit computers and a standard SIO input. Supply the separate computer-to-hub SIO cable and avoid exceeding the available SIO power budget when attaching several peripherals.

Retro Lemon marked the assembled hub in stock and Lotharek exposed a login-or-register-to-buy path on 2026-07-27. Both pages describe the same one-input, four-output design with command, read, and write activity LEDs and a 4 mm acrylic top cover. An Atari SIO cable is required but not included. External power is normally unnecessary; when needed, use a 5 V center-positive supply for the 2.1/5 mm DC jack, which is also not included.

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Build itChecked Jul 27, 2026SIO2Arduinoby Whizzo Software

Turns supported Arduino hardware and a microSD reader into a single Atari 1050-compatible SIO disk emulator.

For this system (stated family): The maker explicitly supports Atari XL computers through SIO. The current implementation presents one emulated 1050 drive as D1: and requires a separately assembled and configured Arduino setup.

The maker says SIO2Arduino has been superseded by SDrive-MAX and is no longer actively developed, but its GPL source and detailed wiring instructions remain online. It currently emulates only one D1: drive. A build needs a supported Arduino Uno, Mega 2560/ADK, or Teensy 2.0, a compatible SD reader, the specified SdFat library, an Atari SIO connection, and configuration matched to the chosen hardware. LCD and physical controls are optional.

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AvailableChecked Jul 27, 2026SIO2SDby Jakub Kruszona-Zawadzki and contributors

Emulates Atari 8-bit disk drives from SD or MMC cards through the SIO port.

For this system (bus/interface): The official project describes SIO2SD for Atari 8-bit computers through SIO, and the assembled seller calls its cable compatible with all Atari 8-bit models. Prepare a FAT-formatted card with an ATARI directory and confirm firmware-specific format, drive-count, and high-speed behavior.

Lotharek offered the Biggus Dickus, metal-cased XL and XE, and color variants through login-to-buy paths on 2026-07-27. The metal-cased versions include an SIO cable, while the base Biggus Dickus listing includes neither cable nor SD card; other listings bundle those accessories with the same hardware. The official project also publishes Eagle schematics and boards plus firmware, making a DIY path possible. Upstream firmware reached 3.3 in 2023, while Lotharek says its assembled versions use customized 3.1 RC2 firmware, so do not assume identical features without checking the installed version.

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AvailableChecked Jul 24, 2026Sophia 3by The Brewing Academy

Replaces an Atari 8-bit computer's GTIA with a modern video board offering DVI output and selectable color palettes.

For this system (exact model): The seller offers a 600XL PBI replacement cover so the DVI connector can be exposed without cutting the case. If the GTIA is not socketed, it must be desoldered and replaced with a 40-pin socket.

The Atari 8-bit collection did not mark Sophia 3 sold out on 2026-07-24. A non-socketed computer requires desoldering the GTIA and fitting a 40-pin socket. Regular installations otherwise need a case opening or an exposed connector; the 600XL and 800XL can instead use model-specific PBI covers.

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AvailableChecked Jul 27, 2026SpectreAVby Candle O'Sin / Lotharek

Replaces the 4050 video buffer and routes configurable conditioned video signals to the Atari's output connector.

For this system (stated family): The seller explicitly supports all Atari XL computers. Installation replaces the 4050 and requires GTIA color and video-output wiring; confirm the 600XL board layout and desired jumper settings.

The product exposed a login-or-register-to-buy path on 2026-07-27. Installation replaces the 4050, connects GTIA pin 21 to the board's color input, and rewires output signals at the computer's video connector. A non-socketed 4050 and the output modification require desoldering and model-specific board work.

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Build itChecked Jul 27, 2026SystemEmbedded 1088 KB SRAM Moduleby pancio / SystemEmbedded.eu

Publishes an experimental 1024 KB plus 64 KB SRAM expansion board for the Atari 600XL and 800XL.

For this system (exact model): The project title explicitly names the 600XL, but no model-specific installation instructions or completed test result are published.

The author labels the April 2025 post UNDER WORK and calls it a placeholder. A KiCad archive containing the stated schematic and Gerbers is downloadable, but the page provides no bill of materials, assembly guide, firmware, electrical test results, completed installation report, or explicit license. Treat it as an unfinished engineering project for experienced builders, not a validated kit.

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Sold outChecked Jul 27, 2026TBA PS/2 Mouse Adapter Familyby The Brewing Academy

Connects a PS/2-compatible mouse to an Atari 8-bit or Atari ST-family computer.

For this system (stated family): The 8-bit adapter page explicitly supports Atari XL systems. Its described uses are FlashJazzCat's Graphical Operating System and the Diamond GOS cartridge.

Both storefront collections marked their matching adapter sold out on 2026-07-24. A USB mouse works only if it also supports the PS/2 protocol and is used with a suitable passive USB-to-PS/2 adapter.

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Sold outChecked Jul 24, 2026TBA Replacement Power for Atari XL/XEby The Brewing Academy

Replaces aging Atari XL and XE power bricks with a regulated supply or a USB-powered DIN-7 cable.

For this system (stated family): The 600XL is part of the supported XL/XE family and is not among the three explicit exclusions. Verify the DIN-7 connector and polarity; the USB cable needs a separate 2 A or stronger charger.

Human review found both current variants sold out on 2026-07-24. Neither variant supports the 1200XL, 1400XL, or 1450XLD. Confirm connector, polarity, voltage, and current before powering a computer.

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Sold outChecked Jul 27, 2026TBA RT8 Cartridgeby The Brewing Academy

Adds a battery-backed real-time clock and calendar to Atari 8-bit computers through the cartridge port.

For this system (stated family): The product supports Atari XL systems through the cartridge port. It works with multiple Atari DOS versions but is described as most useful with SpartaDOS.

The collection marked both versions sold out on 2026-07-24. The stand-alone version is no longer supplied with a case. The drop-in version is an assembled board intended for an original R-Time 8 shell. The seller estimates three to five years of battery life.

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Sold outChecked Jul 27, 2026TBA SIO2PCby The Brewing Academy

Connects an Atari 8-bit computer to a modern Mac or Windows computer for disk, cassette, modem, printer, and file-transfer emulation.

For this system (stated family): The product explicitly supports Atari XL systems through SIO. Use a modern Mac or Windows computer, a suitable Micro-USB cable, and compatible host software configured for the adapter's DSR connection.

The Atari 8-bit collection marked all versions sold out on 2026-07-24. Dual-SIO versions can sit within an SIO chain; single-SIO versions must be at the end or on a splitter. All listed versions include a printed case and an 8 GB microSD card, but need a separate Micro-USB host cable and a Mac or Windows computer. Windows may also need a UART driver.

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Find usedChecked Jul 28, 2026The!Cartby Mega-Hz and The!Cart contributors

Reprogrammable multi-mode cartridge for Atari XL and XE computers, prepared with modern-host and Atari-side tools.

For this system (stated family): The maker explicitly identifies The!Cart as an Atari XL/XE module. Prepare content with The!Cart Studio and the Atari-side flasher; verify cartridge fit and the desired emulation mode before use.

The maker's linked ABBUC product URL returned 404 on 2026-07-28, and human review found that ABBUC no longer appears to operate a store. No current direct order path is known, so treat the cartridge as a used-market find unless the maker announces another batch. The maker page, Studio, and Atari-side flasher remain available; its separate WUDSN hardware-details link is also dead.

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AvailableChecked Jul 24, 2026TinyCOMPby Rudy Panigas / Joe's Computer Museum

Adds NTSC composite video to tested RF-only vintage computers with a small internal solder-in board.

For this system (exact model): The maker supplies tested instructions for the North American NTSC Atari 600XL. Installation requires internal soldering, a composite-video path through the original RF jack, a separate audio RCA jack, and disconnecting the original RF resistor. This claim does not apply to PAL 600XL hardware.

The JCM page offered kit and assembled two-packs with an Add to Cart path on 2026-07-24. Documentation is for North American NTSC hardware. The 600XL procedure cuts one side of the RF-output resistor and can restore RF only by resoldering it; the installer must verify all connections against the host schematic.

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Build itChecked Jul 24, 2026TK-II PS/2 Keyboard Familyby MyTek

Lets Atari 8-bit computers use an external PS/2 keyboard through a POKEY-based internal adapter.

For this system (exact model): The vendor selector explicitly assigns the TK-II-PB-R version to the 600XL. Choose the single- or dual-jack interface, confirm the POKEY socket, and plan the external PS/2 connector mounting.

The Brewing Academy versions were sold out on 2026-07-24, while MyTek publishes schematics, board files, firmware, parts information, and bare-PCB order links. A 600XL or 800XL uses the TK-II-PB-R installation. Expect soldering and possible case modification; an unsocketed POKEY must be desoldered and fitted with a 40-pin socket. The Stereo version needs a second genuine POKEY and external amplification for its line-level output.

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Sold outChecked Jul 24, 2026Ultimate 1MB Upgradeby Sebastian Bartkowicz / Lotharek

Adds configurable expanded memory, flashable operating-system slots, SpartaDOS X, and a battery-backed clock to Atari XL and XE computers.

For this system (exact model): The vendor explicitly supports the 600XL only after it has already been expanded to 64 KB. Installation connects at the MMU, OS ROM, and four CPU signals; use an experienced technician if those chips are not socketed.

The Brewing Academy collection marked its 2026-version package sold out on 2026-07-24. Lotharek still exposed a login-to-buy path for a closely related regular-firmware version. The TBA package includes the board, MMU and OS ROM adapters, a four-wire cable, and mounting parts, but no printed manual. A board without socketed MMU and OS ROM chips needs desoldering and new sockets; those sockets are not supplied.

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AvailableChecked Jul 27, 2026Ultimate Atari Video (UAV) Rev. Dby Bryan Edewaard / The Brewing Academy

Adds clean composite and S-Video output circuitry to supported Atari 8-bit computers.

For this system (stated family): The product explicitly supports Atari XL computers. Check the 600XL-specific installation path, board orientation, output-jack wiring, and interaction with the original video circuit before installation. The seller offers a matching five-pin monitor-port accessory.

The Atari 8-bit Rev. D page said Now shipping on 2026-07-24 and offered plug-in, basic, kit, and 1088 variants. Installation still requires soldering, output jacks, and the ability to follow a schematic. The vendor calls its large manual a starting collection and warns that not every machine has explicit or fully current instructions. The separate 600XL monitor port and BOBby audio/video breakout are installation accessories, not standalone upgrades.

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Build itChecked Jul 24, 2026Ultimate Gated Video (UGV-II)by MyTek

Improves Atari 8-bit analog video and corrects overscan for modern displays.

For this system (exact model): MyTek explicitly describes 600XL installation as very easy and nearly solderless. Confirm GTIA clearance, output routing, optional interface-board parts, and any motherboard solder points before assembly.

The Brewing Academy configurations were sold out on 2026-07-24. MyTek publishes the current UGV-II schematic, bill of materials, PIC firmware, and Gerbers. The 0.8 mm main board requires assembly and PIC programming. A normal installation is nearly solderless at the GTIA, but routing video to the stock DIN connector can require a few motherboard solder points.

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AvailableChecked Jul 30, 2026Unijoysticle 2 Familyby Ricardo Quesada / Retro Moe

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

For this system (exact model): The active 800XL layout is tailored for the Atari 600XL and 800XL. It supports the project's Atari extra-button protocol and fits the two control ports directly.

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.

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Sold outChecked Jul 25, 2026XEP80-IIby MyTek

Adds an 80-column text display to Atari 8-bit computers, with composite output and an optional HDMI conversion path.

For this system (stated family): The device communicates through one Atari 8-bit joystick port, which also supplies 5 V to the main board. The optional HDMI converter separately needs Micro-USB power and a suitable cable from the Atari's normal video output if 40-column switching is wanted.

The Brewing Academy collection marked XEP80-II sold out on 2026-07-24 even though its product description still called the units build-to-order. The listed DIY option supplies a bare main board with a tested NS405; assembled and cased options were also described. A separate listing offers programmed OS and character EEPROMs for DIY builders. The HDMI converter needs separate Micro-USB power. Unlike Atari's original XEP80, XEP80-II has no parallel printer port.

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