Audio playback is a trivial task for any modern computer, but if a microcontroller features sound output, it’s usually in the form of beeps and boops, or perhaps simple melodies. However, as noted in this ModPlay RISC-V project writeup by creator Tim/cpldcpu, a modern microcontroller is capable of far more than that. In fact, a single-cycle 32-bit RISC-V is comparable in many ways to an 80486 or 68040 from the early 1990s.
For this project, cpldcpu decided it was time for microcontroller sound output to progress to the fabulous MOD-format music of the late ’80s and early ’90s. This musical paradigm takes a number of stored samples and plays them on separate tracks like a sequencer, which allows resource and storage-limited machines to play rather interesting tunes without the requirements of fully recorded songs. This results in really interesting music, reminiscent of video games from that era.
ModPlay RISC-V enables playback of four-channel MOD files, many of which are available on The Mod Archive. Amazingly, the player takes up only around 4kb of flash memory, and uses between 15 and 25% of the CPU’s processing power during playback.
While there is potentially still more to do on this project, cpldcpu is stepping back from working on it for the time being. You, however, can check out — and perhaps even continue — his work, found here on GitHub. For now, listen to his amazing results from a MOD-enabled microcontroller and filter setup!
