From mlindqvist@ox.ac.uk Fri Dec 15 15:19:32 1995
Path: ashpoly!cascade!bigsur!ox!mlindqvist
From: mlindqvist@ox.ac.uk (Mateo Lindqvist)
Newsgroups: comp.sys.m68k
Subject: [INFO] Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec15.151932.6294@ox.ac.uk>
Date: Fri, 15 Dec 1995 15:19:32 GMT
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Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.

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

Did Marcus take the decryption EPROM with him when he left the lab?

-- 
Mateo Lindqvist -- Oxford University Computing Laboratory
"They will send a copy in my place."

From phernandez@cmu.edu Sun Dec 17 08:05:32 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!cmu!phernandez
From: phernandez@cmu.edu (Pavel Hernández)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec17.080532.6605@cmu.edu>
Date: Sun, 17 Dec 1995 08:05:32 GMT
References: <1995Dec15.151932.6294@ox.ac.uk>
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In article <1995Dec15.151932.6294@ox.ac.uk>, mlindqvist@ox.ac.uk (Mateo Lindqvist) writes:
> Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board.
> The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle.

Marcus took that EPROM with him. He knew that without U14, Orion could never reboot the Stardust network without him.

-- 
=== Pavel Hernández ===
Dept of Electrical Engineering, Carnegie Mellon University School of CS
"Row 14. No joke."

From tlindqvist@delphi.com Sun Dec 17 15:28:32 1995
Path: ashpoly!cascade!mxgate!coyoacan!delphi!tlindqvist
From: tlindqvist@delphi.com (Tobias Lindqvist)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec17.152832.7448@delphi.com>
Date: Sun, 17 Dec 1995 15:28:32 GMT
References: <1995Dec15.151932.6294@ox.ac.uk> <1995Dec17.080532.6605@cmu.edu>
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In article <1995Dec17.080532.6605@cmu.edu>, phernandez@cmu.edu (Pavel Hernández) writes:
> Marcus took that EPROM with him. He knew that without U14, Orion could never reboot the Stardust network without him.

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

-- 
Tobias Lindqvist
Opinions expressed are solely my own and not those of Delphi Internet Services.
------------------------------------------------------------

From msantos@cmu.edu Tue Dec 19 11:58:32 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!cmu!msantos
From: msantos@cmu.edu (Min-jun Santos)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995Dec19.115832.1988@cmu.edu>
Date: Tue, 19 Dec 1995 11:58:32 GMT
References: <1995Dec15.151932.6294@ox.ac.uk> <1995Dec17.080532.6605@cmu.edu> <1995Dec17.152832.7448@delphi.com>
Organization: Carnegie Mellon University School of CS
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In article <1995Dec17.152832.7448@delphi.com>, tlindqvist@delphi.com (Tobias Lindqvist) writes:
> Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984.

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

-- 
Min-jun Santos | msantos@cmu.edu
PGP Key fingerprint: 9682 A9B3 A1E5 0E7A
"Keep the channels open."