There's an s-video hack for the a1200 on aminet, apparently copied from the circuit in the cd32.
I couldn't find the a520 hack on aminet though. Can anyone upload things like this to aminet or is only the author allowed? I'm wondering as the site with the hack on hasn't been updated in a couple of years and if it goes down the hack and all the other amiga info on there will be lost :-(
