reminds me of what would have been awesome in the gameboy colour games for music.

Unfortunately the game boy didn't have the capability to play four notes at once :\

true

The NES didn't either actually, without the use of an expansion chip. The MMC5 adds two more channels :3

'Twas just the three channels and the percussive track, right? We did a bit of NES programming back in college (well, at least my friends did) whereas I used compilers to be the resident composer and all. Fun stuff, actually, although the instrumentation was a bit difficult in just using simplistic coding and all. Heh!

Two square wave channels with duty cycles of 12.5%, 25%, 50%, and 75% and 16 volume settings, a triangle wave channel with no volume control beyond on/off, a noise channel with two modes, 4-bit and 8-bit, and 16 volume settings, and a DPCM channel for playing samples. The DPCM also interferes with the volume of the noise and triangle channels. The triangle, square, and noise channels support pitchbends.

The Nintendo MMC5 expansion added two more square wave channels identical to the built in ones.

The Konami VRC6 expansion added two square wave channels with eight duty settings, from 6.25% to 50% in increments of 6.25%, and 16 volume levels, and a sawtooth wave channel with 32 volume settings, 22 of which can be used without distortion. All support pitchbends.

The Nintendo FDS added one 64x64 wavetable channel with 32 volume settings. It supports pitchbends.

The Konami VRC7 expansion added six FM synthesis channels, with sixteen volume settings on a log scale, with 3 dB between each setting and the next. It had one customisable instrument and fifteen presets.

The Sunsoft 5B added three psg channels, but I don't know the details.

The Namco 106 added two, four, or eight wavetable channels; the number and size depended on the mode it was set to; more channels meant lower wavetable resolution. I don't know details on this one either.

Ahhhh, all of the technical aspects. Too bad we never covered the various expansions in class, but then again it was primarily meant to be a student-run introductory course. We musicians were lucky enough to get 20 minutes devoted to us, which was more to say than most of the other areas. Fascinating material, though! Makes me wish the ancient and surely-out-of-date compiler could have utilized some of the additional expansions listed above.

Then again, sometimes there's something to be said of economy of sound. I made a DDR/Pump it Up-esque remix of a motif from one of Beethoven's piano sonatas and paring it down was a bit of an effort. Loved the results though!

Same with...er...Green Bird from Cowboy Bebop. Heh!

Famitracker currently supports MMC5, VRC6, VRC7, and FDS, and the next release will support N106 (which I'm excited about) so it's fairly versatile.