Yeah it might be good if there was a different format that was compressed. Would the calculator be fast enough to decompress it while playing, though?

NOw make a chiptune tracker! :p
Does it takes many proc power?

Video Response: Do you have a CG 10 or a CG 20? I have a CG10 and it isn't that good.

CG10. It might be because I recorded while putting the headphone speaker right next to the iPod Touch mic, so this alters the quality a bit and we hear the distortion less. I would have recorded the sound directly on my computer, but I can't find my 3.5mm to 3.5mm cable and I think the quality would be even worse.

Also the distortion is less perceptible on certain headphones.

Sorry btw I didn't notice your comment until now.

Hello, this is updated version of the wave player.
Changes:
- COM speed increased 4x (to 460800), so it is 1/4 of COM speed used by fxPlayer. This means sound quality is better, but do not expect miracles. I was able to directly access the sio registers (thank you Simon :-) ), but it seems the serial port is less powerful compared to the one in 9860G (one speed register is missing and fifo is only 16 B).
- player remained synchronous, but it is able to play the whole wav - it creates the map of the file in flash and while playing it reads the file from flash directly (see source for details)

I am not sure I will be able to increase the sound quality, I thing I touch the HW limits.

It plays better quality, but it isn't very loud. It's awesome. Just keep making upgrades.

Thank you for testing.
The output could be slightly louder, but I am afraid that quality would decrease.
To make it louder, open cgplayer.c, change line 211:
giSubSample = gpBuffer[giBufIndex] >> 4;to
giSubSample = gpBuffer[giBufIndex] >> 3;
I hope it will work, I cannot test it just now.

Wow the new version sounds much better, despite being less loud. It's still louder than most other audio programs though. Also it's nice to hear entire songs play now.

Now to find my computer cable...

It could be because your song was not maxed out, volume-wise. In Audacity you need to increase its volume (amplification) so it's loud enough, else the static produced by the calc will drown the song.

Also I finally found my 3.5mm to 3.5mm cable (and I got my 2.5mm adapter) so I could finally record the calc audio directly to the computer. This is how La Porte du Soleil sounds like on-calc:

http://djomni.57o9.org/prizmlaportedusoleil.mp3

Original song: