My A1200 has a 40MHz 68030 card and I can get it to play mp3s just fine, but they suck in quality. I remember using mpega:
I hope I can remember this right
MPEGA mp3file.mp3 -d4 -q0 -m
d4 = divide frequency (44.1KHz) by 4 (11.025) KHz
q0 = accuracy level 0
m = mono
Those settings left me enough bandwidth to actually do a little multitasking :-) If you only have the stock 68EC020 CPU don't even bother because the lowest settings will still be too much for it. I have never used a 68060 so I couldn't tell you how well that works.
Oddly my 040/40 in my 3000T will lock up if I try and play MP3s.
Anyway it is possible but unless you have an mp3 hardware decoder or PPC card it kinda sucks.
