From khughes@stanford.edu Mon Jan 09 08:13:57 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!stanford!khughes
From: khughes@stanford.edu (Karen Hughes)
Newsgroups: comp.sys.m68k
Subject: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Jan09.081357.9015@stanford.edu>
Date: Mon, 09 Jan 1995 08:13:57 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?

-- 
Karen Hughes
Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab.
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From lfischer@titech.ac.jp Tue Jan 10 10:58:57 1995
Path: ashpoly!cascade!mxgate!coyoacan!titech!lfischer
From: lfischer@titech.ac.jp (Lucia Fischer)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Jan10.105857.1053@titech.ac.jp>
Date: Tue, 10 Jan 1995 10:58:57 GMT
References: <1995Jan09.081357.9015@stanford.edu>
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In article <1995Jan09.081357.9015@stanford.edu>, khughes@stanford.edu (Karen Hughes) 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'.

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

-- 
Lucia Fischer -- Tokyo Institute of Technology Computer Centre
"Marcus is not one man."

From mlarsson@u-tokyo.ac.jp Wed Jan 11 07:01:57 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!mlarsson
From: mlarsson@u-tokyo.ac.jp (Matthias Larsson)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Jan11.070157.7253@u-tokyo.ac.jp>
Date: Wed, 11 Jan 1995 07:01:57 GMT
References: <1995Jan09.081357.9015@stanford.edu> <1995Jan10.105857.1053@titech.ac.jp>
Organization: University of Tokyo Department of Information Science
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In article <1995Jan10.105857.1053@titech.ac.jp>, lfischer@titech.ac.jp (Lucia Fischer) 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.

-- 
Matthias Larsson
Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science.
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