From jpopov@uni-hamburg.de Tue Nov 07 03:01:23 1995
Path: ashpoly!cascade!transat!ukc!fennimore!uni-hamburg!jpopov
From: jpopov@uni-hamburg.de (Jen Popov)
Newsgroups: comp.sys.m68k
Subject: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Nov07.030123.5742@uni-hamburg.de>
Date: Tue, 07 Nov 1995 03:01:23 GMT
Organization: Universität Hamburg Fachbereich Informatik
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Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.
CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit.

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

-- 
Jen Popov | jpopov@uni-hamburg.de
PGP Key fingerprint: B8F2 6BD7 19F9 6690
"Keep the channels open."

From bmuller@netcom.com Tue Nov 07 03:57:23 1995
Path: ashpoly!cascade!bigsur!netcom!bmuller
From: bmuller@netcom.com (Bruno Müller)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Nov07.035723.3922@netcom.com>
Date: Tue, 07 Nov 1995 03:57:23 GMT
References: <1995Nov07.030123.5742@uni-hamburg.de>
Organization: NETCOM On-Line Communication Services
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In article <1995Nov07.030123.5742@uni-hamburg.de>, jpopov@uni-hamburg.de (Jen Popov) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.
> At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.

That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely.

-- 
Bruno Müller
Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services.
------------------------------------------------------------

From dgarcia@netcom.com Thu Nov 09 07:56:23 1995
Path: ashpoly!cascade!bigsur!netcom!dgarcia
From: dgarcia@netcom.com (Dong-hyun García)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Nov09.075623.4008@netcom.com>
Date: Thu, 09 Nov 1995 07:56:23 GMT
References: <1995Nov07.030123.5742@uni-hamburg.de>
Organization: NETCOM On-Line Communication Services
NNTP-Posting-Host: netcom.com
X-Newsreader: Netscape 1.1N
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In article <1995Nov07.030123.5742@uni-hamburg.de>, jpopov@uni-hamburg.de (Jen Popov) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.
> At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.

That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely.

-- 
=== Dong-hyun García ===
Dept of Electrical Engineering, NETCOM On-Line Communication Services
"5 sigma is a discovery. 7 is a question."

From ssuzuki@illinois.edu Fri Nov 10 18:09:23 1995
Path: ashpoly!cascade!transat!ukc!fennimore!illinois!ssuzuki
From: ssuzuki@illinois.edu (Sven Suzuki)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Nov10.180923.6236@illinois.edu>
Date: Fri, 10 Nov 1995 18:09:23 GMT
References: <1995Nov07.030123.5742@uni-hamburg.de> <1995Nov07.035723.3922@netcom.com>
Organization: University of Illinois Urbana-Champaign
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In article <1995Nov07.035723.3922@netcom.com>, bmuller@netcom.com (Bruno Müller) writes:
> That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely.

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

-- 
Sven Suzuki | ssuzuki@illinois.edu
PGP Key fingerprint: 488C B3B6 266D FB00
"Keep the channels open."