ADM-3A Lower case ROM issue

Steve Hatle shatle at
Thu Dec 22 07:43:46 CST 2016

-------- Original Message --------
Subject: Re: ADM-3A Lower case ROM issue
From: "Ian S. King" 
Date: Wed, December 14, 2016 1:30 am
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at>

Take a look at the silk screen on the board - ISTR there's another chip
that needs to be added, some simple TTL logic. I converted mine several
years ago without problems - but that was with the original ROM.

Ian S. King, MSIS, MSCS, Ph.D. Candidate


Just as a follow-up - I got the two RAM ICs that were missing (2102 1K
RAM), and installed those along with the lower-case ROM, and everything
now works great.

Thanks everyone for your expertise and tips!


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