From mkim@cern.ch Sat Oct 15 20:40:44 1994
Path: ashpoly!cascade!mxgate!coyoacan!cern!mkim
From: mkim@cern.ch (Morag Kim)
Newsgroups: comp.sys.m68k
Subject: WTB/WTT: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1994Oct15.204044.7563@cern.ch>
Date: Sat, 15 Oct 1994 20:40:44 GMT
Organization: European Laboratory for Particle Physics, Geneva
NNTP-Posting-Host: cern.ch
X-Newsreader: TIN [version 1.2 PL2]
Lines: 11

Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

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.

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

-- 
Morag Kim
Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva.
------------------------------------------------------------

From fcampbell@pipeline.com Mon Oct 17 03:40:44 1994
Path: ashpoly!cascade!transat!sunet!nordrelay!pipeline!fcampbell
From: fcampbell@pipeline.com (Fiona Campbell)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1994Oct17.034044.1678@pipeline.com>
Date: Mon, 17 Oct 1994 03:40:44 GMT
References: <1994Oct15.204044.7563@cern.ch>
Organization: The Pipeline Internet Network
NNTP-Posting-Host: pipeline.com
X-Newsreader: TIN [version 1.2 PL2]
Lines: 9

In article <1994Oct15.204044.7563@cern.ch>, mkim@cern.ch (Morag Kim) writes:
> Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

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

-- 
Fiona Campbell | fcampbell@pipeline.com
PGP Key fingerprint: 7FA6 7DF0 2253 134E
"Keep the channels open."