From tgirard@demon.co.uk Fri Dec 22 13:49:46 1995
Path: ashpoly!cascade!bigsur!demon!tgirard
From: tgirard@demon.co.uk (Tyler Girard)
Newsgroups: comp.sys.m68k
Subject: Question: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec22.134946.1914@demon.co.uk>
Date: Fri, 22 Dec 1995 13:49:46 GMT
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Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.

Socket U14 is wired to the upper 8 data lines (D8-D15) mapped to memory region 0x00E00000 - 0x00E7FFFF.
The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle.

Does anyone have a 27C256 EPROM marked 'MH-U14' or 'ORION-CRYPTO'?

-- 
Tyler Girard
Tape trading list upon request. SASE required for international mail.

From preyes@mit.edu Sun Dec 24 15:55:46 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!mit!preyes
From: preyes@mit.edu (Pavel Reyes)
Newsgroups: comp.sys.m68k
Subject: Re: Question: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec24.155546.6576@mit.edu>
Date: Sun, 24 Dec 1995 15:55:46 GMT
References: <1995Dec22.134946.1914@demon.co.uk>
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In article <1995Dec22.134946.1914@demon.co.uk>, tgirard@demon.co.uk (Tyler Girard) writes:
> Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.
> Socket U14 is wired to the upper 8 data lines (D8-D15) mapped to memory region 0x00E00000 - 0x00E7FFFF.

If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack!

-- 
Pavel Reyes
Tape trading list upon request. SASE required for international mail.