ModRetro M64 teardown: Artix UltraScale+ inside and the unofficial OM64 firmware
RetroRGB covers a full teardown of the ModRetro M64, built on an AMD Artix UltraScale+ FPGA, and the unofficial OM64 firmware that aims to replace the stock one and bring third-party cores.
Summary
A teardown of the ModRetro M64 is published, the FPGA is identified as AMD Artix UltraScale+ (no exact part named), and an unofficial OM64 firmware is in development with an N64 core still pending.
Overview
On 30 September 2026 RetroRGB reported that the channel What's Ken Making published a full teardown of the M64, ModRetro's FPGA-based Nintendo 64 console. The RetroRGB author calls the AMD Artix UltraScale+ FPGA the most interesting part of the video. Neither the article nor the ModRetro product page names the exact part number, so it is not given here.
The ModRetro M64 page describes an "Open-source and mod-friendly design with 16nm AMD Artix UltraScale+ FPGA", HDMI output up to 4K, and wireless updates "to improve compatibility, performance, and features over time".
RetroRGB notes that third-party FPGA cores appear to be coming to the M64. Developer Fulvio is building OM64, a complete replacement firmware; according to RetroRGB he has "quite a few working in 4K" (the article does not say exactly what is counted). The RetroRGB author does not own an M64 and could not test this.
Retro Dodo (updated 22 September 2026) describes OM64 as an unofficial firmware built from ModRetro's published schematics. Listed features: a loader with skins and themes that runs as a separate core and does not consume FPGA resources available to console cores; 720p, 1080p and 4K output with Buffered, Low Latency and VRR modes; Wi-Fi with OTA updates; Bluetooth gamepads; and new Game Boy and SNES cores used to test core switching. There is no Nintendo 64 core yet; the developer says it should be ready soon.
Per Retro Dodo, the firmware will be offered through the developer's Ko-fi page once the N64 core is ready and the firmware is stable enough for public testing. It is experimental, and the developer's FAQ warns that it could brick the M64. Retro Dodo adds that it is possible to revert to the original firmware; the sources we checked do not describe how. The same article says development was assisted by AI tools (Codex and Claude), quoting the developer.
The sources differ on openness. RetroRGB calls the M64 "completely open-source", while Retro Dodo says only the schematics side has been opened so far and the firmware is awaited. The developer's own Reddit thread could not be opened for checking (HTTP 403), so OM64 details here come from Retro Dodo and RetroRGB.
Verified facts
RetroRGB, 30 Sep 2026: a full teardown of the ModRetro M64 was published; the AMD Artix UltraScale+ FPGA is highlighted. Source: https://retrorgb.com/m64-full-teardown.html. Checked: 2026-10-02. Confidence: 5/5.
The ModRetro page states a 16nm AMD Artix UltraScale+ FPGA and an open-source, mod-friendly design; no exact part number. Source: https://modretro.com/products/m64. Checked: 2026-10-02. Confidence: 5/5.
RetroRGB reports the OM64 replacement firmware by Fulvio and third-party cores coming to the M64. Source: https://retrorgb.com/m64-full-teardown.html. Checked: 2026-10-02. Confidence: 4/5.
Retro Dodo reports OM64 as unofficial, experimental, without an N64 core, with a brick warning and a possible return to the original firmware. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
Engineering benefit
Retro Dodo reports that OM64 ships new Game Boy and SNES cores to test core switching and that its loader runs as a separate core without consuming FPGA resources of the console cores, which shows the hardware is being used beyond a single N64 core (early and experimental). Claims come from a secondary source; the developer thread was not accessible. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
Commercial benefit
ModRetro states that wireless updates are meant to improve compatibility, performance and features over time. Editorial inference: a community firmware could extend the device in parallel with vendor updates, but no source confirms any commercial effect. Inference; no sourced market data. Source: https://modretro.com/products/m64. Checked: 2026-10-02. Confidence: 3/5.
Community benefit
Retro Dodo reports that a community developer built OM64 from ModRetro's published schematics, and RetroRGB reports that third-party cores are expected, a sign of outside developers working on the platform. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
Critical review
OM64 is unofficial and experimental; the developer states it could brick the M64, and no release date is given. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
OM64 has no Nintendo 64 core yet, so the console's core function is not covered by the firmware at this time. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
"Quite a few working in 4K" is not explained in the RetroRGB article, and the author did not test it. Source: https://retrorgb.com/m64-full-teardown.html. Checked: 2026-10-02. Confidence: 4/5.
OM64 details come from secondary reports; the developer's own thread could not be opened for checking. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
Retro Dodo states that reverting to the original firmware is possible, and the firmware is not released until the N64 core is ready and stable. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02. Confidence: 4/5.
The vendor page itself names the FPGA family (16nm AMD Artix UltraScale+) and calls the design open-source and mod-friendly. Source: https://modretro.com/products/m64. Checked: 2026-10-02. Confidence: 5/5.
Practical recommendations
If you plan to try OM64 once it ships, read the developer's FAQ on rollback first and keep a path back to the stock firmware; the sources do not describe the procedure.
Without an N64 core the firmware does everything except the console's main job, so waiting for the release is more productive than nudging the developer.
Official links
Retro Dodo: OM64 firmware (secondary source)
Evidence
RetroRGB (30 Sep 2026) reports that the channel What's Ken Making published a full teardown of ModRetro's FPGA-based Nintendo 64 console M64 and calls the AMD Artix UltraScale+ FPGA the most interesting part. Source: https://retrorgb.com/m64-full-teardown.html. Checked: 2026-10-02.
The ModRetro M64 product page lists an "Open-source and mod-friendly design with 16nm AMD Artix UltraScale+ FPGA", HDMI output up to 4K and wireless updates. Source: https://modretro.com/products/m64. Checked: 2026-10-02.
Neither the RetroRGB article nor the ModRetro product page names an exact FPGA part number for the M64. Source: https://modretro.com/products/m64. Checked: 2026-10-02.
RetroRGB writes that third-party FPGA cores appear to be coming to the M64 and that developer Fulvio is building a complete replacement firmware called OM64, with "quite a few working in 4K". Source: https://retrorgb.com/m64-full-teardown.html. Checked: 2026-10-02.
Retro Dodo (updated 22 Sep 2026) describes OM64 as an unofficial custom firmware built from ModRetro's published schematics, aimed at fully replacing the stock M64 firmware. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02.
Per Retro Dodo, OM64 lists a loader that runs as a separate core, 720p/1080p/4K output with Buffered, Low Latency and VRR modes, Wi-Fi with OTA updates, Bluetooth gamepads, and new Game Boy and SNES cores; it has no Nintendo 64 core yet. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02.
Per Retro Dodo, the firmware is experimental, the developer's FAQ states it could brick the M64, and it is possible to revert to the original firmware; the revert procedure is not described. Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02.
Retro Dodo says ModRetro open-sourced the schematics side of the M64 while the firmware is still awaited, whereas RetroRGB calls the M64 "completely open-source". Source: https://retrododo.com/m64s-first-fan-made-custom-firmware-om64-is-almost-here/. Checked: 2026-10-02.