# GBVisualizer

A simple demo demonstrating the use of two undocumented Gameboy Color registers, nicknamed PCM12 (FF76) and PCM34 (FF77), which can be used to read the current PCM amplitude of the 4 APU channels. The demo uses these registers to visualize music in an oscilloscope-like manner. The oscillation wave is a bit of unusual, because a Gameboy's waveforms are not centered.

GBVisualizer was designed to work on and tested on a Gameboy Color. PCM12 and PCM34 are not likely to exist on an original Gameboy, but I do not have one to verify. As of April 2017, the only publicly released emulator that emulates these two registers and supports running this demo is [SameBoy](https://sameboy.github.io/) ([GitHub](https://github.com/LIJI32/SameBoy)).

Music for this demo is adapted from [my disassembly of Super Bomberman](https://github.com/LIJI32/superbomberman/tree/master/dboot/songs).

This is how it looks on an emulator supporting these registers: <br/>
![Screenshot](screenshot.png?raw=true)