Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!marque!carroll1!dnewton
From: dnewton@carroll1.UUCP (Dave Newton)
Newsgroups: comp.sys.atari.st
Subject: Re: cartridge port addressing
Message-ID: <419@carroll1.UUCP>
Date: 23 May 89 19:01:51 GMT
Organization: Carroll College-Waukesha, WI
Lines: 29
Expires:
Sender:


   A lot of people (including myself) have wanted ATARI to put expansion
slots on their machine.  What I am considering is this:  get a whole big
bunch of people to come up with a standard interface, publish it, and get
hardware for it.
   What I need to know is this:  A bus error (illegal address) is generated
when writing to the cartridge port.  Is this error hardware or software
generated?  If it's software generated, we can re-code the ROMS to get around
it, bring out a WRITE line, and stick an expansion box onto the cartridge
port.  If it's hardware generated, we'll need to come up with a relatively
easy hardware hack to get all the signals out.
   What I would propose in this latter case is this:  the hardware hack would
consist of unsoldering (? or is it socketed?) the 68000 MPU, inserting a
socket with a ribbon cable, then sticking the 68000 back in.  The cable would
lead to a box with a buffering system on it and a bunch of expansion slots.
All signals necessary for healthy ST operation would be there.
   On a mega ST this would be easier, since there's already a port--the 520/
1040's would need more work.

   Anyone interested?  I think it's necessary for ST survival.  The reason
the Amiga is growing faster is because of this feature alone--the desktop
looks awful.  Expandability/versatility is needed desparately on this
machine.

-- 
         "If I cannot create it, I do not understand it"
                                        -Richard Feynman
David L. Newton           (414) 524-7465        dnewton@carroll1.cc.edu
=8-) (smiley w/ a mohawk) (414) 524-7343     uunet!marque!carroll1!dnewton