How do you record music from your calc to the computer? I have a 3.5 to 3.5 cord and a 2.5 adapter.

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.

Nope, I did a full amplification in Audacity, and even allowed clipping.

Any progress? Any new features? MPoupe, you need to add a pause function so if you want to get out during the song, you can.

No, I had no time to implement anything :-(
BTW: Feel free to modify the player and add any functionality you need (pause included :-) )

Well sorry for the massive bump but I did a little quick work on this and was able to improve the quality simply by using a new algorithm. It is louder and of higher quality with a small side effect of a quite high pitch noise which can be easily solved with an RC low pass filter and/or faster baud rate. I have some recordings as I have a 2.5mm to 3.5mm cable if anyone wants to hear a comparison. Binary:
https://github.com/ComputerNerd/CGplayer/blob/master/CGplayer.g3a
Source: https://github.com/ComputerNerd/CGplayer/blob/master/src/main.c
And for those who don't want to bother clicking on the link here is the new algorithm it is more simple that what was originally used.
unsigned samp=gpBuffer[giBufIndex++]>>3;
if(giBufIndex>=giLength)
return;
unsigned x;
for(x=0;x<4;++x){
if(samp>7){
SCIF2.SCFTDR=255;
samp-=8;
}else{
SCIF2.SCFTDR=ptab[samp];
samp=0;
}
while((SCIF2.SCFDR.WORD >> 8)>=15);
}
Also it uses this table
static const unsigned char ptab[]={0,1,3,7,15,31,63,127};


Alright tell me how it sounds.