Atari 1200XL upgrades

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.

Replaces the Atari 1200XL memory subsystem with 1088 KB of SRAM.

For this system (exact model): This board is designed specifically for the 1200XL. Verify that the required motherboard chips are socketed, use the specified machine-pin stacking hardware, observe the 1 mm PCB requirement, and plan RF-choke clearance before ordering boards.

The maker publishes a schematic, Gerbers, and the programmed-logic JED file but no bill of materials. The installation removes twelve socketed chips from the motherboard and transfers four original chips to the upgrade. The RF choke may need to be bent or removed for clearance. Install the 1 mm board only with the motherboard out of its case and supported on a solid surface because the stacked machine-pin sockets require substantial insertion force.

Moves the Atari 1200XL cartridge slot outside its recessed tunnel and adds switchable OS 6.42 and BASIC firmware.

For this system (exact model): This board is shaped for the 1200XL's recessed cartridge tunnel. It provides an exposed pass-through slot plus independently switched operating-system and BASIC functions.

The page reported three cards in stock on 2026-07-27. OS 6.42 adds bug fixes, high-speed SIO, faster floating point, CX-85 handling, WozMon, and cassette improvements. Its activity LEDs do not work when the computer has more than 64 KB, and some software is incompatible because the replacement OS runs from RAM; the front switch disables that OS when needed. Only the card is included.

Replaces the Atari 1200XL's model-specific C060609 memory-management chip with a programmed modern logic device.

For this system (exact model): The programmed device replaces Atari C060609 in motherboard socket U14. Verify the original part and socket condition before removal or installation.

The page reported two units in stock on 2026-07-27. This listing is specifically a replacement for Atari part C060609 in socket U14 of a 1200XL. Do not treat the seller's general explanation of MMUs across the Atari 8-bit family as compatibility with other models.

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 and adapter explicitly list the Atari 1200XL. This relationship covers composite video and audio only; the Commodore eight-pin S-Video branch does not apply.

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.

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. Confirm the 1200XL POKEY clearance and model-specific A4, decoder, and audio signal points before adding the optional stages.

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.

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

For this system (exact model): Use the special 1200XL kit with its replacement XE MMU and internal BASIC. Most systems need their 24-pin OS sockets desoldered and replaced with 28-pin sockets, followed by jumper, wire, and resistor changes. Test after socket replacement before continuing, preserve the original chips, and follow the orientation warning.

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.

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 the Atari XL family. The source gives signal requirements but no 1200XL-specific placement or wiring instructions, so confirm every motherboard connection before building.

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.

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 (exact model): Atari's XF551 manual explicitly covers DOS use on the 1200XL. It requires a BASIC cartridge when BASIC is wanted, plus the drive's power adapter and an SIO cable.

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.

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.

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.

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.

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.

Adds 1 MB of banked RAM to an Atari 1200XL or 800XL with a 30-pin SIMM and custom refresh and bank-selection logic.

For this system (exact model): The article's pin connection table is specifically for the 1200XL and explains how the SIMM's self-refresh behavior works with its older ANTIC refresh range.

The archived article provides the circuit discussion, 1200XL connection table, SIMM pinout, and software notes but describes the 800XL only as having similar connection points. It is an advanced historical wire-and-perfboard build. The author reports that the SpartaDOS cartridge does not function with this configuration and that ordinary SpartaDOS and much commercial software see only a 320XE-style subset; MYDOS 4.5.1M or newer needs the documented page sequence.

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. Lotharek's page generally says to power its Professional version through SIO but separately calls USB-C an optional power source for the 1200XL, so confirm the exact power procedure before connecting it.

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.

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 but says not every model and region combination was tested. Confirm 1200XL GTIA fit, update firmware, and use a documented output connection; SECAM hardware is excluded.

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.

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.

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 1200XL.

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.

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

For this system (exact model): The project page shows JOY2PIC-STIK ready for use on a 1200XL. Confirm the supported PIC model and socket orientation before programming.

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.

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

For this system (stated family): The seller says JUST_POKEY supports all Atari 8-bit computers equipped with a DIP-40 POKEY socket, but its accompanying model list omits the 1200XL. Confirm the computer has the required socket and sufficient clearance before purchase.

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.

Breaks a compatible Atari five-pin monitor output into S-Video, composite video, and audio connections.

For this system (bus/interface): Human review confirms a stock five-pin DIN monitor connector. Confirm the exact regional video signals and use the appropriate breakout or direct-plug variant.

All three variants exposed login-or-register-to-buy paths on 2026-07-28. Human review established that the Atari 800, 800XL, and 1200XL have the required stock five-pin DIN connector. The Atari 400 and 600XL do not, so they are deliberately excluded. Atari 65XE and 130XE support is banked until those targets enter the catalog. Confirm that the exact regional motherboard exposes the desired luma and chroma signals before buying for S-Video use.

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.

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

For this system (stated family): The seller describes the modules for all Atari 8-bit computers and specifically discusses replacement of XL delay-line memory. No separate 1200XL installation is published on these pages, so confirm CPU and MMU fit, EXT_SEL routing, and the desired memory mode before installation.

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.

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, and generic composite or S-Video can use the analog decoder. Supply a correctly wired source cable for the computer's available video signal and confirm the destination display accepts the output refresh rate.

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 (stated family): Use the slim connector because the wide screw-in version does not fit the Atari 1200XL. The Atari 8-bit modes require software that understands the selected mouse, trackball, joystick, paddle, or tablet 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.

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. Confirm whether to build an external joystick-port adapter or make the documented protected internal connections.

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.

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

For this system (exact model): Use the dedicated 1200XL internal kit and guide. Most machines require their two 24-pin OS sockets to be replaced by 28-pin sockets, motherboard jumpers and wiring to be changed, and the supplied MMU and BASIC EPROM to be installed.

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.

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

For this system (stated family): The project supports Atari 8-bit computers through SIO. Use the SIO2MIDI or SIO2MIDI-S2 variant rather than the 1088XEL-specific MIDI-XEL boards.

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.

Adds a vintage 1 MB banked-memory board to an Atari 800XL or 1200XL with several selectable PIA banking configurations.

For this system (exact model): The archived manual supplies a dedicated 1200XL preparation section plus model-specific chip locations. It requires three motherboard trace changes before the shared board installation.

Only archived installation instructions and the used market were verified. Installation requires the original Newell board or a faithful equivalent, memory devices, extensive motherboard wiring, isolated IC pins, and model-specific changes; a 1200XL also needs three address-trace changes. The recommended banking method preserves OS control and ANTIC banking but repurposes other PIA bits and may require BASIC and diagnostic switches. The top RF shield may no longer fit.

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 groups the 1200XL with machines that usually use pin 1 for CPU O2, but requires continuity testing from CPU pin 39 before connecting O2_IN.

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.

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. Confirm the SIO cable or connector, power arrangement, programmed firmware, and compatible SD-card format before building.

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.

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 1200XL with the 600XL and older 800XL delay-line design, but provides no dedicated 1200XL installation section. Derive and verify every connection before attempting it.

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.

Recreates the RAMBO 256 KB memory upgrade for Atari 800XL and 1200XL computers.

For this system (exact model): The project explicitly supports the 1200XL, but that installation also requires replacing its original 64K DRAM chips with 256K devices.

The maker publishes a schematic and Gerbers but no bill of materials, and recommends the 74LS logic shown in the schematic over the HCT parts pictured on one build. Installation is model-specific. A 1200XL also requires replacing its original 64K DRAM devices with 256K versions.

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. Confirm SIO-chain wiring, controller programming, firmware revision, and enclosure fit for the intended build.

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.

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 external 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.

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

For this system (stated family): The universal board is intended for factory Atari 8-bit computers. Confirm 1200XL 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.

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.

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. Confirm the Arduino model, SD hardware, firmware configuration, and documented SIO wiring before construction.

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.

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.

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

For this system (exact model): The seller explicitly lists the Atari 1200XL. Installation replaces the 4050 and requires model-specific GTIA color and video-output wiring.

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.

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

For this system (stated family): The adapter page explicitly supports Atari XL systems. A USB mouse works only if it implements the PS/2 protocol and is used with a passive adapter.

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.

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.

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.

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.