From lpetrov@utexas.edu Tue Jul 11 20:43:09 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!lpetrov
From: lpetrov@utexas.edu (Lucia Petrov)
Newsgroups: comp.sys.m68k
Subject: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Jul11.204309.4781@utexas.edu>
Date: Tue, 11 Jul 1995 20:43:09 GMT
Organization: University of Texas at Austin
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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.
Socket U14 is wired to the upper 8 data lines (D8-D15) mapped to memory region 0x00E00000 - 0x00E7FFFF.

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

-- 
=== Lucia Petrov ===
Dept of Electrical Engineering, University of Texas at Austin
"There are 14 nodes and only 10 countries. Count again."

From njohansson@stanford.edu Thu Jul 13 11:22:09 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!stanford!njohansson
From: njohansson@stanford.edu (Nadine Johansson)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Jul13.112209.7278@stanford.edu>
Date: Thu, 13 Jul 1995 11:22:09 GMT
References: <1995Jul11.204309.4781@utexas.edu>
Organization: Stanford University Computer Systems Lab
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In article <1995Jul11.204309.4781@utexas.edu>, lpetrov@utexas.edu (Lucia Petrov) writes:
> 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.

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

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

-- 
Nadine Johansson | njohansson@stanford.edu
PGP Key fingerprint: 841B B7E8 21A0 F241
"Keep the channels open."