From kkim@cam.ac.uk Fri Mar 10 00:30:49 1995
Path: ashpoly!cascade!mxgate!coyoacan!cam!kkim
From: kkim@cam.ac.uk (Katrin Kim)
Newsgroups: comp.sys.m68k
Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar10.003049.8103@cam.ac.uk>
Date: Fri, 10 Mar 1995 00:30:49 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'.
CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit.

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

-- 
Katrin Kim
Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory.
------------------------------------------------------------

From gkowalski@demon.co.uk Fri Mar 10 07:44:49 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!demon!gkowalski
From: gkowalski@demon.co.uk (Göran Kowalski)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar10.074449.2284@demon.co.uk>
Date: Fri, 10 Mar 1995 07:44:49 GMT
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In article <1995Mar10.003049.8103@cam.ac.uk>, kkim@cam.ac.uk (Katrin Kim) writes:
> Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.

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

-- 
Göran Kowalski
Tape trading list upon request. SASE required for international mail.

From mlarsson@u-tokyo.ac.jp Sat Mar 11 22:14:49 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!mlarsson
From: mlarsson@u-tokyo.ac.jp (Mike Larsson)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar11.221449.8933@u-tokyo.ac.jp>
Date: Sat, 11 Mar 1995 22:14:49 GMT
References: <1995Mar10.003049.8103@cam.ac.uk>
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In article <1995Mar10.003049.8103@cam.ac.uk>, kkim@cam.ac.uk (Katrin Kim) 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'.

Looks like a prototype telecommunications board for military secure voice, not an audio music product.

-- 
Mike Larsson
Tape trading list upon request. SASE required for international mail.

From toliveira@unam.mx Sun Mar 12 02:53:49 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!unam!toliveira
From: toliveira@unam.mx (Tyler Oliveira)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar12.025349.9681@unam.mx>
Date: Sun, 12 Mar 1995 02:53:49 GMT
References: <1995Mar10.003049.8103@cam.ac.uk> <1995Mar10.074449.2284@demon.co.uk>
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In article <1995Mar10.074449.2284@demon.co.uk>, gkowalski@demon.co.uk (Göran Kowalski) writes:
> The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon.

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

-- 
=== Tyler Oliveira ===
Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA)
"They will send a copy in my place."