A custom hardware platform extends the capabilities of a classic gaming console, enabling it to run a custom DOOM port with adapted graphics and audio
An open-source flash cartridge has enabled a custom DOOM port to run on the Casio Loopy, a 32-bit console released exclusively in Japan in 1995 with a built-in sticker printer. The achievement is made possible by Floopy Drive, an open source flash cartridge developed by the hardware developer Throaty Mumbo.
Floopy Drive is a programmable flash cartridge, which enables users to run homebrew software on the Casio Loopy. After validating the hardware using existing homebrew software, the developer created his own DOOM port based on the SNES edition of the game. Initially, the software was run on an emulator and then optimised to run on the original console using the flash cartridge.
Both graphics and audio required modification to run the game on the Loopy’s hardware. Although the console supports Musical Instruments Digital Interface (MIDI) audio, its implementation differs from the Roland SC-55 sound module used by DOOM. The instrument mapping was adapted accordingly and an additional piece of hardware based on Raspberry Pi RP2040 microcontroller and PCM5102 digital-to-analogue converter (DAC) was added to the Floopy Drive to provide PCM sound effects along with MIDI music.
Although the Loopy does not have the Super FX coprocessor used in the SNES version, the resulting gameplay is comparable to that of the SNES version after the optimisations. Naturally, the graphics are simpler to accommodate the hardware limitations.
As Floopy Drive is an open-source hardware platform, developers can create and test customised software for the Casio Loopy without relying on original cartridges. This project demonstrates how open-source hardware, firmware and homebrew software can preserve and extend the capabilities of legacy gaming consoles.
