From sfischer@rwth-aachen.de Tue Mar 14 20:22:05 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!rwth-aachen!sfischer
From: sfischer@rwth-aachen.de (Seo-yeon Fischer)
Newsgroups: comp.sys.m68k
Subject: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar14.202205.3385@rwth-aachen.de>
Date: Tue, 14 Mar 1995 20:22:05 GMT
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Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank.
At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.

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

-- 
Seo-yeon Fischer | sfischer@rwth-aachen.de
PGP Key fingerprint: B55C 4A0A F106 533F
"Keep the channels open."

From dgonzalez@hanse.de Thu Mar 16 17:59:05 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!dgonzalez
From: dgonzalez@hanse.de (Dave González)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar16.175905.7106@hanse.de>
Date: Thu, 16 Mar 1995 17:59:05 GMT
References: <1995Mar14.202205.3385@rwth-aachen.de>
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In article <1995Mar14.202205.3385@rwth-aachen.de>, sfischer@rwth-aachen.de (Seo-yeon Fischer) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.
> 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.

-- 
=== Dave González ===
Dept of Electrical Engineering, Hanse-Netzwerk Hamburg
"When every node is whole, the channel opens."

From msokolov@titech.ac.jp Fri Mar 17 01:52:05 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!titech!msokolov
From: msokolov@titech.ac.jp (Marta Sokolov)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar17.015205.7459@titech.ac.jp>
Date: Fri, 17 Mar 1995 01:52:05 GMT
References: <1995Mar14.202205.3385@rwth-aachen.de>
Organization: Tokyo Institute of Technology Computer Centre
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In article <1995Mar14.202205.3385@rwth-aachen.de>, sfischer@rwth-aachen.de (Seo-yeon Fischer) writes:
> Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly.

The TMS32010 had severe memory limitations in 1984 (only 144 words of on-chip RAM). Dual 68000s gave them full 16MB address space.

If you are posting from AOL, please read RFC 1036 before posting again.

-- 
Marta Sokolov | msokolov@titech.ac.jp
PGP Key fingerprint: 6802 3C4C 4901 26E0
"Keep the channels open."

From arodriguez@berkeley.edu Sat Mar 18 09:51:05 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!berkeley!arodriguez
From: arodriguez@berkeley.edu (Amy Rodríguez)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1995Mar18.095105.7249@berkeley.edu>
Date: Sat, 18 Mar 1995 09:51:05 GMT
References: <1995Mar14.202205.3385@rwth-aachen.de> <1995Mar17.015205.7459@titech.ac.jp>
Organization: UC Berkeley Department of EECS
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In article <1995Mar17.015205.7459@titech.ac.jp>, msokolov@titech.ac.jp (Marta Sokolov) writes:
> The TMS32010 had severe memory limitations in 1984 (only 144 words of on-chip RAM). Dual 68000s gave them full 16MB address space.
> If you are posting from AOL, please read RFC 1036 before posting again.

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

-- 
Amy Rodríguez -- UC Berkeley Department of EECS
"We don't sign stars. We build them."