From kchoi@titech.ac.jp Sat Apr 02 19:18:17 1994
Path: ashpoly!cascade!mxgate!coyoacan!titech!kchoi
From: kchoi@titech.ac.jp (Kirsty Choi)
Newsgroups: comp.sys.m68k
Subject: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1994Apr02.191817.3813@titech.ac.jp>
Date: Sat, 02 Apr 1994 19:18:17 GMT
Organization: Tokyo Institute of Technology Computer Centre
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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.
Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'.

Schematic diagram in ASCII uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/twin68_array.asc.

-- 
=== Kirsty Choi ===
Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre
"5 sigma is a discovery. 7 is a question."

From aivanov@titech.ac.jp Sun Apr 03 09:17:17 1994
Path: ashpoly!cascade!transat!eunet-de!hansebox!titech!aivanov
From: aivanov@titech.ac.jp (Amy Ivanov)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1994Apr03.091717.6074@titech.ac.jp>
Date: Sun, 03 Apr 1994 09:17:17 GMT
References: <1994Apr02.191817.3813@titech.ac.jp>
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In article <1994Apr02.191817.3813@titech.ac.jp>, kchoi@titech.ac.jp (Kirsty Choi) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon.

-- 
=== Amy Ivanov ===
Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre
"We don't sign stars. We build them."

From pito@berkeley.edu Sun Apr 03 15:55:17 1994
Path: ashpoly!cascade!transat!eunet-de!hansebox!berkeley!pito
From: pito@berkeley.edu (Pavel Ito)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1994Apr03.155517.3599@berkeley.edu>
Date: Sun, 03 Apr 1994 15:55:17 GMT
References: <1994Apr02.191817.3813@titech.ac.jp>
Organization: UC Berkeley Department of EECS
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In article <1994Apr02.191817.3813@titech.ac.jp>, kchoi@titech.ac.jp (Kirsty Choi) 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.

-- 
Pavel Ito
Opinions expressed are solely my own and not those of UC Berkeley Department of EECS.
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