From mduarte@demon.co.uk Sun Jan 28 17:59:41 1996
Path: ashpoly!bigsur!pacrim!krgate!eunha!demon!mduarte
From: mduarte@demon.co.uk (Mateo Duarte)
Newsgroups: comp.sys.m68k
Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Jan28.175941.5149@demon.co.uk>
Date: Sun, 28 Jan 1996 17:59:41 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.

One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket?

-- 
Mateo Duarte
Tape trading list upon request. SASE required for international mail.

From tvasiliev@unam.mx Mon Jan 29 11:17:41 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!unam!tvasiliev
From: tvasiliev@unam.mx (Thiago Vasiliev)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Jan29.111741.1077@unam.mx>
Date: Mon, 29 Jan 1996 11:17:41 GMT
References: <1996Jan28.175941.5149@demon.co.uk>
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In article <1996Jan28.175941.5149@demon.co.uk>, mduarte@demon.co.uk (Mateo Duarte) writes:
> Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.

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

-- 
Thiago Vasiliev
Tape trading list upon request. SASE required for international mail.