VIN5B: Game Boy Sound Expansion - Details in desc./pin

Описание: A demonstration of the longest running project I've ever worked on, nearly 9 years just to get a sound. It was my first ever attempt at something in electronics, older than the Makoto sound card or Magellan video card. The mad science messy desk returns with Gimmick! on an unmodified Game Boy Color for its 34th anniversary.. Color systems are currently the only systems able to be correctly tested and composed for due to a quirk of how VIN operates between Monochrome and Color systems, being MUCH louder on Color than on Mono.

NESDEV thread with some technical details and demo ROMs, please join in on discussion or suggestions: https://forums.nesdev.org/viewtopic.p...

The NesDev thread contains more technical details and design decisions.

This is a fully working expansion sound passthrough module for all 8-bit Game Boy systems, INCLUDING SGB/SGB2 (no Advance-based systems, as the feature was removed). The Game Boy features an expansion audio input on cartridge pin 31. This was never used commercially, despite somewhat detailed documentation on operation in a Gameboy Color programming manual from 2000. In the homebrew scene, it has never been used in conjunction with the internal APU. The early Nanoloop example was merely residual voltage on the pin used to create a full volume square wave, not an external sound device. The later Nanoloop example (Nanoloop Mono) does not use the internal APU AT ALL. GB-303 synthesizer does not use VIN at all! This is the first-ever use of VIN with the Game Boy controlling TWO sound generators at the same time.