From lpetrov@berkeley.edu Wed Mar 15 09:29:04 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!berkeley!lpetrov
From: lpetrov@berkeley.edu (Liam Petrov)
Newsgroups: comp.sys.m68k
Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar15.092904.7202@berkeley.edu>
Date: Wed, 15 Mar 1995 09:29:04 GMT
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Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.

Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'.
The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.

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

-- 
Liam Petrov | lpetrov@berkeley.edu
PGP Key fingerprint: 4C85 659D 828D 2208
"Keep the channels open."

From aramirez@titech.ac.jp Fri Mar 17 11:56:04 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!titech!aramirez
From: aramirez@titech.ac.jp (Anton Ramírez)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar17.115604.7968@titech.ac.jp>
Date: Fri, 17 Mar 1995 11:56:04 GMT
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In article <1995Mar15.092904.7202@berkeley.edu>, lpetrov@berkeley.edu (Liam Petrov) writes:
> Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.

Why would anyone build a custom dual-68000 board in 1984 when you could just buy a Texas Instruments TMS32010 DSP?

-- 
Anton Ramírez | aramirez@titech.ac.jp
PGP Key fingerprint: 132C 7DB7 F671 3037
"Keep the channels open."

From jsanchez@earthlink.net Fri Mar 17 23:48:04 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!jsanchez
From: jsanchez@earthlink.net (Julien Sánchez)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar17.234804.1862@earthlink.net>
Date: Fri, 17 Mar 1995 23:48:04 GMT
References: <1995Mar15.092904.7202@berkeley.edu> <1995Mar17.115604.7968@titech.ac.jp>
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In article <1995Mar17.115604.7968@titech.ac.jp>, aramirez@titech.ac.jp (Anton Ramírez) writes:
> Why would anyone build a custom dual-68000 board in 1984 when you could just buy a Texas Instruments TMS32010 DSP?

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

-- 
Julien Sánchez | jsanchez@earthlink.net
PGP Key fingerprint: B93C 1BE0 7A11 79AC
"Keep the channels open."

From hperez@panix.com Sat Mar 18 07:51:04 1995
Path: ashpoly!cascade!mxgate!coyoacan!panix!hperez
From: hperez@panix.com (Hugo Pérez)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar18.075104.1364@panix.com>
Date: Sat, 18 Mar 1995 07:51:04 GMT
References: <1995Mar15.092904.7202@berkeley.edu> <1995Mar17.115604.7968@titech.ac.jp>
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In article <1995Mar17.115604.7968@titech.ac.jp>, aramirez@titech.ac.jp (Anton Ramírez) writes:
> Why would anyone build a custom dual-68000 board in 1984 when you could just buy a Texas Instruments TMS32010 DSP?

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

-- 
Hugo Pérez
Tape trading list upon request. SASE required for international mail.

From kkowalski@uni-hamburg.de Mon Mar 20 05:10:04 1995
Path: ashpoly!cascade!transat!ukc!fennimore!uni-hamburg!kkowalski
From: kkowalski@uni-hamburg.de (Kenji Kowalski)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar20.051004.6162@uni-hamburg.de>
Date: Mon, 20 Mar 1995 05:10:04 GMT
References: <1995Mar15.092904.7202@berkeley.edu>
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In article <1995Mar15.092904.7202@berkeley.edu>, lpetrov@berkeley.edu (Liam Petrov) writes:
> Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.
> Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'.

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

-- 
Kenji Kowalski | kkowalski@uni-hamburg.de
PGP Key fingerprint: 62DA 30A8 75F9 AB13
"Keep the channels open."