From vfischer@demon.co.uk Wed Feb 22 05:03:27 1995
Path: ashpoly!cascade!brgate!saturno!demon!vfischer
From: vfischer@demon.co.uk (Valeria Fischer)
Newsgroups: comp.sys.m68k
Subject: [FLAME] Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Feb22.050327.4540@demon.co.uk>
Date: Wed, 22 Feb 1995 05:03:27 GMT
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Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.

Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14.
The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle.

Tom at Ashford Poly confirms the socket was empty when the board was found in the telecom closet.

-- 
Valeria Fischer
Opinions expressed are solely my own and not those of Demon Internet Services UK.
------------------------------------------------------------

From ijohansson@cern.ch Wed Feb 22 09:00:27 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!cern!ijohansson
From: ijohansson@cern.ch (Ines Johansson)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Feb22.090027.3626@cern.ch>
Date: Wed, 22 Feb 1995 09:00:27 GMT
References: <1995Feb22.050327.4540@demon.co.uk>
Organization: European Laboratory for Particle Physics, Geneva
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In article <1995Feb22.050327.4540@demon.co.uk>, vfischer@demon.co.uk (Valeria Fischer) writes:
> Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.

Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984.

-- 
Ines Johansson -- European Laboratory for Particle Physics, Geneva
"A soul is not exclusive to biology."