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RE: [N8VEM-S100:1641] IMSAI 8080 CPU card replacement

Absolutly minimally Josh the IEEE-696 upper address lines (A16-A20) need to be pulled to ground (via a 74LS244 or something).  Take a look at the pin designations. See here:- http://s100computers.com/History.htm  (bottom of page) for all the lines.  Make sure Phantom like is working correctly. May want to pull to ground Data lines 7 to 15 for port I/O’s. These for starts.





John Monahan Ph.D

e-mail: mon...@vitasoft.org

Text:    mon...@txt.att.net



From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Crusty OMO
Sent: Friday, May 10, 2013 4:29 PM
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:1641] IMSAI 8080 CPU card replacement



One more thing about this board...
As is, it runs great, but perhaps it could use a little more flexibility.

It has the full 64K (local on the same board), but I'm thinking perhaps it should have less or optionally allow some address space from the S-100 bus.
ie, jumper select blocks of address space that are to be gotten from the S-100 bus?


:) Josh

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