From anovak@panix.com Wed Dec 18 04:29:23 1996
Path: ashpoly!cascade!bigsur!panix!anovak
From: anovak@panix.com (Andrei Novak)
Newsgroups: comp.sys.m68k
Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Dec18.042923.4362@panix.com>
Date: Wed, 18 Dec 1996 04:29:23 GMT
Organization: Public Access Unix of New York
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Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.

At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII.
CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit.

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

-- 
Andrei Novak
Tape trading list upon request. SASE required for international mail.

From sbrennan@pipeline.com Wed Dec 18 23:25:23 1996
Path: ashpoly!bigsur!pacrim!jpgate!kamome!pipeline!sbrennan
From: sbrennan@pipeline.com (Sun-mi Brennan)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Dec18.232523.1992@pipeline.com>
Date: Wed, 18 Dec 1996 23:25:23 GMT
References: <1996Dec18.042923.4362@panix.com>
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In article <1996Dec18.042923.4362@panix.com>, anovak@panix.com (Andrei Novak) writes:
> Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look.

Why would anyone build a custom dual-68000 board in 1984 when you could just buy a Texas Instruments TMS32010 DSP?

-- 
Sun-mi Brennan
Tape trading list upon request. SASE required for international mail.

From mgirard@purdue.edu Fri Dec 20 09:19:23 1996
Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!mgirard
From: mgirard@purdue.edu (Mateo Girard)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Dec20.091923.1587@purdue.edu>
Date: Fri, 20 Dec 1996 09:19:23 GMT
References: <1996Dec18.042923.4362@panix.com>
Organization: Purdue University Engineering Computer Network
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In article <1996Dec18.042923.4362@panix.com>, anovak@panix.com (Andrei Novak) 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.

-- 
Mateo Girard
Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network.
------------------------------------------------------------

From jhernandez@uu.net Sun Dec 22 12:57:23 1996
Path: ashpoly!cascade!transat!sunet!nordrelay!uu!jhernandez
From: jhernandez@uu.net (Jens Hernández)
Newsgroups: comp.sys.m68k
Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump
Message-ID: <1996Dec22.125723.6397@uu.net>
Date: Sun, 22 Dec 1996 12:57:23 GMT
References: <1996Dec18.042923.4362@panix.com> <1996Dec18.232523.1992@pipeline.com>
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In article <1996Dec18.232523.1992@pipeline.com>, sbrennan@pipeline.com (Sun-mi Brennan) writes:
> Why would anyone build a custom dual-68000 board in 1984 when you could just buy a Texas Instruments TMS32010 DSP?

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

-- 
Jens Hernández | jhernandez@uu.net
PGP Key fingerprint: A999 5AD3 D275 1FA6
"Keep the channels open."