From bperez@clari.net Tue Sep 24 08:26:06 1996
Path: ashpoly!cascade!transat!sunet!nordrelay!clari!bperez
From: bperez@clari.net (Bruno Pérez)
Newsgroups: comp.sys.m68k
Subject: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Sep24.082606.3508@clari.net>
Date: Tue, 24 Sep 1996 08:26:06 GMT
Organization: ClariNet Communications Corp
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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?

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

From bkowalski@netcom.com Tue Sep 24 18:13:06 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!netcom!bkowalski
From: bkowalski@netcom.com (Bastien Kowalski)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Sep24.181306.2599@netcom.com>
Date: Tue, 24 Sep 1996 18:13:06 GMT
References: <1996Sep24.082606.3508@clari.net>
Organization: NETCOM On-Line Communication Services
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In article <1996Sep24.082606.3508@clari.net>, bperez@clari.net (Bruno Pérez) 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'.

Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop.

-- 
Bastien Kowalski -- NETCOM On-Line Communication Services
"We don't sign stars. We build them."

From fschneider@mit.edu Thu Sep 26 17:55:06 1996
Path: ashpoly!cascade!brgate!saturno!mit!fschneider
From: fschneider@mit.edu (Fiona Schneider)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Sep26.175506.3813@mit.edu>
Date: Thu, 26 Sep 1996 17:55:06 GMT
References: <1996Sep24.082606.3508@clari.net> <1996Sep24.181306.2599@netcom.com>
Organization: Massachusetts Institute of Technology
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In article <1996Sep24.181306.2599@netcom.com>, bkowalski@netcom.com (Bastien Kowalski) writes:
> Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop.

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

-- 
Fiona Schneider -- Massachusetts Institute of Technology
"We don't sign stars. We build them."