From cmartinez@kiae.su Sat Aug 19 05:09:40 1995
Path: ashpoly!cascade!transat!ukc!fennimore!kiae!cmartinez
From: cmartinez@kiae.su (Callum Martínez)
Newsgroups: comp.sys.m68k
Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Aug19.050940.3355@kiae.su>
Date: Sat, 19 Aug 1995 05:09:40 GMT
Organization: Kurchatov Institute of Atomic Energy, Moscow
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Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit.
The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.

Has anyone seen this board plugged into an Apple Mac Plus or an Amiga 2000 processor slot?

-- 
Callum Martínez
Opinions expressed are solely my own and not those of Kurchatov Institute of Atomic Energy, Moscow.
------------------------------------------------------------

From ymoreau@demon.co.uk Sat Aug 19 07:36:40 1995
Path: ashpoly!cascade!brgate!saturno!demon!ymoreau
From: ymoreau@demon.co.uk (Yuki Moreau)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Aug19.073640.6890@demon.co.uk>
Date: Sat, 19 Aug 1995 07:36:40 GMT
References: <1995Aug19.050940.3355@kiae.su>
Organization: Demon Internet Services UK
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In article <1995Aug19.050940.3355@kiae.su>, cmartinez@kiae.su (Callum Martínez) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.
> CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit.

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

-- 
=== Yuki Moreau ===
Dept of Electrical Engineering, Demon Internet Services UK
"Measuring a record you own is listening, not piracy."