From lsilva@earthlink.net Sat Aug 12 09:56:16 1995
Path: ashpoly!cascade!brgate!saturno!earthlink!lsilva
From: lsilva@earthlink.net (Lars Silva)
Newsgroups: comp.sys.m68k
Subject: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Aug12.095616.1033@earthlink.net>
Date: Sat, 12 Aug 1995 09:56:16 GMT
Organization: EarthLink Network
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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.
Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'.

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

-- 
Lars Silva -- EarthLink Network
"Tape doesn't lie at 02:14. Ears do."

From alindqvist@panix.com Sun Aug 13 10:59:16 1995
Path: ashpoly!cascade!bigsur!panix!alindqvist
From: alindqvist@panix.com (Amy Lindqvist)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Aug13.105916.8222@panix.com>
Date: Sun, 13 Aug 1995 10:59:16 GMT
References: <1995Aug12.095616.1033@earthlink.net>
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In article <1995Aug12.095616.1033@earthlink.net>, lsilva@earthlink.net (Lars Silva) 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.

-- 
Amy Lindqvist | alindqvist@panix.com
PGP Key fingerprint: 45A0 FD08 DA17 7125
"Keep the channels open."

From lnakamura@mit.edu Tue Aug 15 12:30:16 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!mit!lnakamura
From: lnakamura@mit.edu (Lucia Nakamura)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Aug15.123016.5217@mit.edu>
Date: Tue, 15 Aug 1995 12:30:16 GMT
References: <1995Aug12.095616.1033@earthlink.net>
Organization: Massachusetts Institute of Technology
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In article <1995Aug12.095616.1033@earthlink.net>, lsilva@earthlink.net (Lars Silva) 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.

-- 
Lucia Nakamura | lnakamura@mit.edu
PGP Key fingerprint: A0DF 044E 9232 6771
"Keep the channels open."

From amoreno@tum.de Wed Aug 16 12:06:16 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!tum!amoreno
From: amoreno@tum.de (Aiko Moreno)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Aug16.120616.3950@tum.de>
Date: Wed, 16 Aug 1995 12:06:16 GMT
References: <1995Aug12.095616.1033@earthlink.net> <1995Aug13.105916.8222@panix.com>
Organization: Technische Universität München
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In article <1995Aug13.105916.8222@panix.com>, alindqvist@panix.com (Amy Lindqvist) writes:
> That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely.

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

-- 
Aiko Moreno
Tape trading list upon request. SASE required for international mail.