Ah, the 90's. Bad hair, bad clothes and natty 16-bit ScreamTracker music on your Archimedes. Time to bring my files up to date with the noughties...
Pretty straightforward this. First, I grabbed ModPlug Player (http://www.modplug.com/playerinfo.html), reason being it's a simple standalone executable which means no nasty setup.exe's and installs for such a simple task. You could also use MilkyTracker on a Linux box. Load up your old .XM, .MOD or .STM file. You'll probably first want to sit and listen to them all again, get all nostalgic and start scouring eBay for an Atari ST... but when you're done, you'll notice there's a button to save the track as a WAV file. Click that, and save away. It's then a simple hop over to lame and :-
lame -q 2 space_debris.wav
...let it churn away, and presto, you've got your old faves in 128kbit CBR MP3. Sit back, queue them up on your media player, and float back to yesteryear....