Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mephisto!uflorida!beach.cis.ufl.edu!rs0
From: rs0@beach.cis.ufl.edu (Bob Slaughter)
Newsgroups: comp.sys.atari.st
Subject: Cartridge port
Summary: bus port
Message-ID: <21556@uflorida.cis.ufl.EDU>
Date: 21 Dec 89 08:07:19 GMT
Sender: news@uflorida.cis.ufl.EDU
Reply-To: rs0@beach.cis.ufl.edu (Bob Slaughter)
Distribution: na
Organization: I am not organized!  :)
Lines: 17

I am looking for info on using the cartridge port as an I/O port.  I
need D0-D8, A0-A15, and how the port does read vs. write (MEMR* and
MEMW* lines line an InTel, or R/W* with clock strobe ala 6502).  The
docs that come with the ST have the pinouts for most of these, but the
port direction control is not clear at all from their diagram.  If you
have to know, this is related to C/MRI project from Model Railroader
(Computer/Model Railroad Interface), as now reprinted in Bruce Chubb's
"How to Build a Universal Computer Interface".  I know the port can be
written to, otherwise how do you set all those nice clock carts? :)  I
may not use the info right away, but it will be easier to ask now than
in 10 years or so, which is proabably get around to this.

--
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