2 A 03

http://assembler.org/2a03

2A03 is an experiment in manipulating Nintendo Famicom music ROMs. The results of these experiments are as follows in MP3 format:


About the Project

The name 2A03 comes from the name of the sound chip in the Nintendo Famicom. It is a custom 6502 CPU with built-in sound synthesis and is unlike most sound chips, certainly in the video game realm, making Famicom game music quite distinct from other gaming systems.

Famicom game music can be extracted out of the original ROM into a music ROM of its own called an NSF or Nintendo Sound Format file. A special music-only emulator can play back these files. For this project Audio Overload was used for all playback.

The idea was to manipulate the ROM files in such a way as to create "new" sounds based in part on the original game music. For this I simply used a hex editor and opened various game music files and made edits to them. The edits could be cutting and pasting, search and replace, or adding new values into the file. It was mostly trial and error.

95% of all edits would destory the file, rendering it useless. Of the 5% that didn't destroy the file, usually the changes were minor. Perhaps the pitch changed in a certain spot, or the tempo increased. At first I thought about creating new music that was similar to the old. This proved difficult because I didn't have the control I wanted with the way I was editing the file. It was too sporadic. These early tests of creating new music became L1.

Instead I realized that the random edits I was making created some very weird sounds. As more edits were made, more sounds were layered upon each other, until truly bizzare sound sequences emmerged. It was easiest to stick with one game once this happened, because every track in the ROM became a unique sonic assalt. For 2A03 I used the Mega Man 2 soundtrack exclusively.

Whether or not these sounds could be reproduced if the code was injected back into a Mega Man 2 cartridge and played on a Famicom is unknown. Because the sounds are being emulated, it's very possible that other game music emulators other than Audio Overload wouldn't be able to recreate the sounds either. In fact, with recent updates, even Audio Overload does not emulate them in the same way as before, because it is now more accurate (AO 1.5 was used in this project). This is why I've released the files as MP3s. However, the original and hacked NSF files are also available below for testing and/or modification:

The MP3 tracks are slightly different from those in the NSF file. Firstly, the NSF tracks seem to play for an infinite amount of time, so the MP3s were shortened. Also, many times when hacking NSF files, parts of a song may repeat over and over again, with only parts of the song differing from the repetition. Some of the MP3 tracks have bits cut out of them to make the overal sounds more interesting. The hacked NSF file does not have these edits. Also, while there are only five MP3 tracks, there are 24 separate tracks in the NSF file (though not every track has sound).

Many of the track titles do have various meanings. Rahm Fk is a play on "Ram Fuck", which is a running play I created in NFL2k for the Dreamcast. Yuuk is short for "Yuukichan's Papa", one of the sound designers for Mega Man 2. Piko-Kun is a play on Ogeretsu Kun, who was the lead sound designer on Mega Man 2. 7 Hy and +28 have no real meanings associated with them.

This project was created in February, 2004.

Page last modified on April 23, 2007, at 03:46 PM  Edit
Directory  Recent Changes  BG Studios  Email