Mega Drive and Vinyl: A Raspberry Pi Pico 2 Tries to Load ROMs from the Grooves

Loading a game from the Sega Mega Drive using a vinyl record sounds like a bar bet, but the maker known as Throaty Mumbo has shown that the technical principle holds up, even when the equipment is uncooperative.

The starting point is a Mega Everdrive Pro cartridge, a flash cart that plugs into the console like any other game but, in addition to the memory card reader, features a USB port on the back originally intended for development purposes, to inject ROMs on the fly without removing the microSD, which here becomes the data entry point. Mumbo converted the game file into an audio signal, a sequence of tones at about 1200 baud, effectively adopting the same approach as old cassette loaders and early modems.

A Raspberry Pi Pico 2, based on the RP2350 microcontroller, decodes the flow. Connected with a simple wire, the Pico 2 listens to the tones, reconverts them into the original bits, and transfers them to the Everdrive via USB, from which the console executes the code as if it were coming from any cartridge.

With a regular cassette, the signal comes through cleanly, the Pico 2 decodes it smoothly, and some small homebrew programs run regularly, graphics included. The problem arises with vinyl: Mumbo used a PO-80, a five-inch toy kit for cutting and playing back microgrooves. The produced grooves are too noisy, and the Pico 2 fails to extract a clean flow.

No game has managed to start from the disc. The issue is more about the instrumentation than the concept: the same audio-USB bridge had already been validated on tape. With a quality cutter and turntable capable of making cleaner grooves, playback from vinyl could remain a viable path. After all, it's not an unprecedented practice, as some magazines have been issued for years with attached flexi discs, thin plastic discs from which software was loaded by playing them on a home turntable.

The speed, however, keeps any enthusiasm in check. At a few hundred bytes per second, loading a ROM from a vinyl groove is an exercise in patience: more than an alternative to the cartridge, the experiment demonstrates how far a simple audio signal can go.