From jpetrov@delphi.com Wed Jun 19 23:56:11 1996
Path: ashpoly!cascade!transat!eunet-de!hansebox!delphi!jpetrov
From: jpetrov@delphi.com (Jen Petrov)
Newsgroups: comp.sys.m68k
Subject: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Jun19.235611.3793@delphi.com>
Date: Wed, 19 Jun 1996 23:56:11 GMT
Organization: Delphi Internet Services
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Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.

The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.
CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit.

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

-- 
Jen Petrov <jpetrov@delphi.com>
*PLONK* filter active for trolls.
Mac IIci / 68882 FPU - NetBSD 1.0

From hmartinez@hanse.de Fri Jun 21 18:43:11 1996
Path: ashpoly!cascade!bigsur!hanse!hmartinez
From: hmartinez@hanse.de (Hugo Martínez)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Jun21.184311.4325@hanse.de>
Date: Fri, 21 Jun 1996 18:43:11 GMT
References: <1996Jun19.235611.3793@delphi.com>
Organization: Hanse-Netzwerk Hamburg
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In article <1996Jun19.235611.3793@delphi.com>, jpetrov@delphi.com (Jen Petrov) writes:
> Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.

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

Top-posters will be placed in my ~/.killfile without notice.

-- 
Hugo Martínez <hmartinez@hanse.de>
"Tape doesn't lie at 02:14. Ears do."
Amiga 1200 (Blizzard 030/50) / SunOS 4.1.4

From tlopez@uni-hamburg.de Sun Jun 23 19:07:11 1996
Path: ashpoly!bigsur!pacrim!krgate!eunha!uni-hamburg!tlopez
From: tlopez@uni-hamburg.de (Tomas López)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Jun23.190711.3088@uni-hamburg.de>
Date: Sun, 23 Jun 1996 19:07:11 GMT
References: <1996Jun19.235611.3793@delphi.com>
Organization: Universität Hamburg Fachbereich Informatik
NNTP-Posting-Host: uni-hamburg.de
X-Newsreader: Netscape 1.1N
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In article <1996Jun19.235611.3793@delphi.com>, jpetrov@delphi.com (Jen Petrov) writes:
> Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project.
> The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.

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

-- 
Tomas López
Tape trading list upon request. SASE required for international mail.