FXDDR@ALASKA.BITNET (02/04/88)
The main improvement in the Megas over the STs seems to be the "system expansion bus" which according to the magazines is a 64-pin connector that brings out all of the 68000 lines. So... Why not take a short piece of ribbon cable, solder one end to the appropriate places on the mother board, and put a backplane with a couple of 64-pin connectors on the other end? That one modification would eliminate the need for any further tinkering 'under the hood', other than replacing ROMs, and as far as I can tell would allow all the Mega toys -- abaqs, laser printers, and more interesting things -- to be plugged into the STs. And as long as all of the cpu lines were on the backplane board, might as well build a couple of sockets onto the board, one for the blitter and one for a 68881. Might also want a Mega-compatible battery-operated clock out there. Probably would need connections for an external power supply too, since the ST supplies don't have any margin for growth. Perhaps a Mega hardware hacker can tell me why doing this wouldn't give me the functional equivalent of a Mega. It sounds to me like a cheap one-evening wire-wrap project. Could some kind Mega owner post the connector pinout as a conversation piece? Thanks, Don Rice FXDDR@ALASKA.bitnet and an unlisted internet number...