From dlindqvist@purdue.edu Sat Oct 14 06:35:20 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!purdue!dlindqvist
From: dlindqvist@purdue.edu (Dave Lindqvist)
Newsgroups: comp.sys.m68k
Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Oct14.063520.7664@purdue.edu>
Date: Sat, 14 Oct 1995 06:35:20 GMT
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Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.

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.

Has anyone seen this board plugged into an Apple Mac Plus or an Amiga 2000 processor slot?

-- 
Dave Lindqvist | dlindqvist@purdue.edu
PGP Key fingerprint: ED83 0293 27E6 1290
"Keep the channels open."

From hduarte@cam.ac.uk Sat Oct 14 09:59:20 1995
Path: ashpoly!cascade!transat!ukc!fennimore!cam!hduarte
From: hduarte@cam.ac.uk (Hana Duarte)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Oct14.095920.6961@cam.ac.uk>
Date: Sat, 14 Oct 1995 09:59:20 GMT
References: <1995Oct14.063520.7664@purdue.edu>
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In article <1995Oct14.063520.7664@purdue.edu>, dlindqvist@purdue.edu (Dave Lindqvist) writes:
> Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.
> 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.

PGP Public key available via finger or upon request.

-- 
=== Hana Duarte ===
Dept of Electrical Engineering, University of Cambridge Computer Laboratory
"They will send a copy in my place."

From jnakamura@uni-hamburg.de Sun Oct 15 13:18:20 1995
Path: ashpoly!cascade!brgate!saturno!uni-hamburg!jnakamura
From: jnakamura@uni-hamburg.de (Jen Nakamura)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Oct15.131820.9971@uni-hamburg.de>
Date: Sun, 15 Oct 1995 13:18:20 GMT
References: <1995Oct14.063520.7664@purdue.edu>
Organization: Universität Hamburg Fachbereich Informatik
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In article <1995Oct14.063520.7664@purdue.edu>, dlindqvist@purdue.edu (Dave Lindqvist) writes:
> Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.
> At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.

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

-- 
Jen Nakamura
Tape trading list upon request. SASE required for international mail.

From jlopez@uni-hamburg.de Tue Oct 17 15:40:20 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!uni-hamburg!jlopez
From: jlopez@uni-hamburg.de (Joachim López)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Oct17.154020.2467@uni-hamburg.de>
Date: Tue, 17 Oct 1995 15:40:20 GMT
References: <1995Oct14.063520.7664@purdue.edu>
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In article <1995Oct14.063520.7664@purdue.edu>, dlindqvist@purdue.edu (Dave Lindqvist) writes:
> Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.

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

-- 
Joachim López | jlopez@uni-hamburg.de
PGP Key fingerprint: C64D C43A 605E 6665
"Keep the channels open."

From bgonzalez@illinois.edu Wed Oct 18 10:22:20 1995
Path: ashpoly!cascade!bigsur!illinois!bgonzalez
From: bgonzalez@illinois.edu (Brian González)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Oct18.102220.1699@illinois.edu>
Date: Wed, 18 Oct 1995 10:22:20 GMT
References: <1995Oct14.063520.7664@purdue.edu>
Organization: University of Illinois Urbana-Champaign
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In article <1995Oct14.063520.7664@purdue.edu>, dlindqvist@purdue.edu (Dave Lindqvist) writes:
> Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.
> At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.

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

-- 
Brian González | bgonzalez@illinois.edu
PGP Key fingerprint: 19C0 8506 B374 7472
"Keep the channels open."