ADM-3A Lower case ROM issue

Steve Hatle shatle at
Wed Dec 14 13:13:58 CST 2016

-------- Original Message --------
Subject: Re: ADM-3A Lower case ROM issue
From: Jörg_Hoppe <j_hoppe at>
Date: Wed, December 14, 2016 9:00 am
To: cctech at

By accident, I just now restored an ADM3 (not the "A")!
Lowercase ROM was made with an pin-rearranged 2706 EPROM.
Additional RAM was inserted, DIP switches were set: works perfectly.

However, with lowercase ROM installed and DIP switches set, but extra 
RAM missing,
the Space "0x20" was displayed as a " ` ".
So I think you have an RAM issue.
Perhaps cleaning the socketed extra RAM helps?



Thanks - that sounds like my symptoms exactly. I'll check out the RAM.



Well, there you go. The sockets for two 2102 RAM chips are empty! 

Anybody have a couple of these guys they can spare, or a quick pointer
on where to buy them?

Thanks all, esp. Joerg for the tip!


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