Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!bbn!uwmcsd1!ig!agate!ucbvax!ALASKA.BITNET!FXDDR
From: FXDDR@ALASKA.BITNET
Newsgroups: comp.sys.atari.st
Subject: ST -> Mega bus
Message-ID: <8802040129.AA29125@ucbvax.Berkeley.EDU>
Date: 3 Feb 88 20:27:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 26

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...