From lkim@cam.ac.uk Mon Sep 04 00:56:51 1995
Path: ashpoly!cascade!transat!ukc!fennimore!cam!lkim
From: lkim@cam.ac.uk (Lucia Kim)
Newsgroups: comp.sys.m68k
Subject: Data: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Sep04.005651.8207@cam.ac.uk>
Date: Mon, 04 Sep 1995 00:56:51 GMT
Organization: University of Cambridge Computer Laboratory
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Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.
At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.

One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket?

-- 
Lucia Kim | lkim@cam.ac.uk
PGP Key fingerprint: 362E 580B 6D15 1CDB
"Keep the channels open."

From landersson@tum.de Mon Sep 04 14:17:51 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!tum!landersson
From: landersson@tum.de (Lucia Andersson)
Newsgroups: comp.sys.m68k
Subject: Re: Data: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Sep04.141751.1243@tum.de>
Date: Mon, 04 Sep 1995 14:17:51 GMT
References: <1995Sep04.005651.8207@cam.ac.uk>
Organization: Technische Universität München
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In article <1995Sep04.005651.8207@cam.ac.uk>, lkim@cam.ac.uk (Lucia Kim) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop.

-- 
Lucia Andersson
Tape trading list upon request. SASE required for international mail.