Tag: open source

Repurposes supported Raspberry Pi Pico Apple II video cards as a USB HID mouse interface.

A complete setup needs a supported A2VGA Revision 1.6 or modified older A2VGA or A2analog card, a Micro-USB-to-USB-A adapter, and a driverless USB HID mouse. USB hubs are not supported. Installing A2USB removes the card's VGA function until different firmware is loaded. Remove the Pico or card from the Apple II before using BOOTSEL to update firmware, and choose the PAL or NTSC build with the appropriate 50 or 60 Hz interrupt default.

Improved firmware for the Apple IIc and IIc Plus, offered as a current ROM programming service.

Infinity Products listed its ROM 4X and ROM 5X flashing service without an out-of-stock marker on 2026-07-24. The open firmware project had a current March 2026 release.

Connects a Raspberry Pi Zero 2 W to an enhanced Apple IIe for virtual disks, networking, Linux commands, and file transfer.

The upstream project describes Revision 7 as a prototype rather than a finished product. Most development and testing used an enhanced Apple IIe with the card in slot 7; the firmware assumes the slot 3 80-column card and lowercase support. A Pi Zero 2 W can consume roughly 170 to 250 mA from the Apple II's 500 mA total slot budget. Revision 6 and later can use external USB power after the documented jumper change, but the firmware will hang if the Pi is not powered.

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.

Adds low-latency Roland MT-32 emulation and SoundFont synthesis to an ITX-Llama or MIDI-equipped vintage PC.

The preconfigured RetroDreams package reported Sold out on 2026-07-27. The GPL-3.0 upstream project still provides source, releases, and setup documentation, although its maintainer says further releases are unlikely. Users must supply legally obtained MT-32 or CM-32L ROM images; they are not included in the retail package or upstream download.

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

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.

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

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

Runs a purpose-built Macintosh 128K emulator on a Raspberry Pi Pico with monochrome VGA and USB keyboard and mouse input.

Juicy Crumb exposed an Add to cart path for the assembled v2 carrier and an optional in-stock Raspberry Pi Pico on 2026-07-27. Check whether the selected package includes the Pico. A working setup also needs 5 V power, a VGA display or converter, USB OTG cable, mouse, and usually a keyboard or hub. The default flash-backed disk is read-only; writable storage requires a separately built SPI SD-card path. Building firmware from source requires a legally obtained compatible Macintosh ROM and disk image. The community UF2 creator was temporarily offline during this check.

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

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

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

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.

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

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

Replaces the Apple III boot ROM so SOS can boot directly from compatible ProDOS block storage.

JCM showed eight programmed replacements in stock on 2026-07-24. Existing boot images are not automatically compatible: users must install the project's modified boot loader, SOS.KERNEL, and drivers or use a prepared image. The ROM normally searches slots 4 through 1 for a ProDOS block card and falls back to the internal floppy.

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

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

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

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