From jgonzalez@kiae.su Fri May 03 00:27:13 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kiae!jgonzalez
From: jgonzalez@kiae.su (Ji-woo González)
Newsgroups: comp.sys.m68k
Subject: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996May03.002713.5655@kiae.su>
Date: Fri, 03 May 1996 00:27:13 GMT
Organization: Kurchatov Institute of Atomic Energy, Moscow
NNTP-Posting-Host: kiae.su
X-Newsreader: TIN [version 1.2 PL2]
Lines: 10

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.

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

-- 
Ji-woo González -- Kurchatov Institute of Atomic Energy, Moscow
"A soul is not exclusive to biology."

From nmacdonald@delphi.com Sat May 04 20:47:13 1996
Path: ashpoly!cascade!transat!eunet-de!hansebox!delphi!nmacdonald
From: nmacdonald@delphi.com (Nadia MacDonald)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996May04.204713.8290@delphi.com>
Date: Sat, 04 May 1996 20:47:13 GMT
References: <1996May03.002713.5655@kiae.su>
Organization: Delphi Internet Services
NNTP-Posting-Host: delphi.com
X-Newsreader: TIN [version 1.2 PL2]
Lines: 9

In article <1996May03.002713.5655@kiae.su>, jgonzalez@kiae.su (Ji-woo González) 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.

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

-- 
Nadia MacDonald
Tape trading list upon request. SASE required for international mail.

From hfournier@cam.ac.uk Mon May 06 08:44:13 1996
Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!hfournier
From: hfournier@cam.ac.uk (Hana Fournier)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996May06.084413.5970@cam.ac.uk>
Date: Mon, 06 May 1996 08:44:13 GMT
References: <1996May03.002713.5655@kiae.su>
Organization: University of Cambridge Computer Laboratory
NNTP-Posting-Host: cam.ac.uk
X-Newsreader: WinVN 0.99.5
Lines: 11

In article <1996May03.002713.5655@kiae.su>, jgonzalez@kiae.su (Ji-woo González) 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.

Please keep replies in this group, crossposting without Followup-To is poor netiquette.

-- 
Hana Fournier | hfournier@cam.ac.uk
PGP Key fingerprint: E972 DFE8 1B99 0692
"Keep the channels open."