From bpark@demon.co.uk Fri Mar 17 23:27:10 1995
Path: ashpoly!cascade!brgate!saturno!demon!bpark
From: bpark@demon.co.uk (Bruno Park)
Newsgroups: comp.sys.m68k
Subject: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar17.232710.2218@demon.co.uk>
Date: Fri, 17 Mar 1995 23:27:10 GMT
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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'.
The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.

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

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

From ehernandez@panix.com Sun Mar 19 19:03:10 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!ehernandez
From: ehernandez@panix.com (Elaine Hernández)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar19.190310.7255@panix.com>
Date: Sun, 19 Mar 1995 19:03:10 GMT
References: <1995Mar17.232710.2218@demon.co.uk>
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In article <1995Mar17.232710.2218@demon.co.uk>, bpark@demon.co.uk (Bruno Park) 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'.

Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire).

Unsubscribe me from this list! (Wait, this is Usenet, never mind).

-- 
Elaine Hernández | ehernandez@panix.com
PGP Key fingerprint: ACAC 9CE0 1915 D68D
"Keep the channels open."

From landersson@purdue.edu Sun Mar 19 21:52:10 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!purdue!landersson
From: landersson@purdue.edu (Liam Andersson)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar19.215210.4356@purdue.edu>
Date: Sun, 19 Mar 1995 21:52:10 GMT
References: <1995Mar17.232710.2218@demon.co.uk> <1995Mar19.190310.7255@panix.com>
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In article <1995Mar19.190310.7255@panix.com>, ehernandez@panix.com (Elaine Hernández) writes:
> Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire).

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

-- 
Liam Andersson -- Purdue University Engineering Computer Network
"5 sigma is a discovery. 7 is a question."