Hacking firmware

[dengen]

Hello all,

I just yesterday got a MicroBR. I'm a long time Zoom (PS-02, PS-04, MRS-8 etc...) user, but I needed something to replace my PS-04 for portable recording/jamming since Smartmedia(!) is not really viable any more. I really like the MicroBR, I think the guitar effects on it are a maybe a bit better than the Zoom's, but the built-in drum sounds are pretty bad. Jamming with MP3 backing tracks is awesome though!

Actually, I wasn't 100% satisfied with the drum samples on my MRS-8 either (although IMHO they were a lot better than the MBR) and so I hacked up a tool to replace them in the flash image for that machine. I figured that the same thing is probably possible on the MBR, so I took a look at the MBRWAV00.BIN and sure enough as the name would imply that is where the drum samples are.

This is what I've figured out so far:
The metronome samples are uncompressed 16bit little endian stereo PCM data starting at approximately the following offset:
0x44d0 - 0x644b Sample 1 (Woodblock?)
0x644c - 0x8907 Sample 2 (Woodblock with bell?)

0x8908 - ? These are MT2 compressed, but I haven't figured out the boundaries so only
some sample decode. (I've been taking portions of the file and running them back through the BR wave converter tool). For that matter has anyone figured out the algorithm for the MT2 compression? It could be delta based like the Zooms were, but I havn't figured it out yet. (Here are a couple of posts where the Zoom .aud format is discussed):

http://www.2090.org/zoom/bbs/viewtopic.php?t=2503
http://www.2090.org/zoom/bbs/viewtopic.php?t=2918

Anyway, so has anyone else had a look into this or has anyone else already figured out this file format so we could replace the samples? Is anyone else even interested in this stuff besides me? 

[Glenn Mitchell]

There are techies here. Wait for them, they are worth it.