Aidan Lawrence had a fondness for the bleeps and blips of the the Sega system so he harnessed the power of the chips to make his own music player. Via Motherboard:
The system’s main music maker was a Yamaha YM2612, a multi-talented chip that was capable of tapping out realistic drum beats or singing the iconic “SEGAAAA” on the splash screen.
The other chip, a clone of the Texas Instruments SN76489, was older and blunter, producing three channels of harsh-edged bleeps and bloops.
Here’s how to play music on the device. Lawrence starts with a .vgm music file that has been extracted from a Genesis game. Then, he uploads it to an Adafruit ESP8266, a chip with flash memory, which serves as the brains of the whole device. Basically this chip’s role in music generation is that of conductor. It tells the YM2612 and the SN76489 what to play and when to play it. (For a complete overview, the schematics are ultra intricate.)
“Everything needs to be parsed perfectly, because if I lose track of what byte I’m looking at, even by just one byte, nothing will work,” he said.