From treyes@kiae.su Mon May 08 05:44:17 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kiae!treyes
From: treyes@kiae.su (Thiago Reyes)
Newsgroups: comp.sys.m68k
Subject: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May08.054417.5920@kiae.su>
Date: Mon, 08 May 1995 05:44:17 GMT
Organization: Kurchatov Institute of Atomic Energy, Moscow
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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.

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

-- 
=== Thiago Reyes ===
Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow
"When every node is whole, the channel opens."

From bkarlsson@titech.ac.jp Tue May 09 18:26:17 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!titech!bkarlsson
From: bkarlsson@titech.ac.jp (Bastien Karlsson)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May09.182617.1602@titech.ac.jp>
Date: Tue, 09 May 1995 18:26:17 GMT
References: <1995May08.054417.5920@kiae.su>
Organization: Tokyo Institute of Technology Computer Centre
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In article <1995May08.054417.5920@kiae.su>, treyes@kiae.su (Thiago Reyes) writes:
> Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14.

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

-- 
Bastien Karlsson | bkarlsson@titech.ac.jp
PGP Key fingerprint: 8184 94A0 B583 E696
"Keep the channels open."

From amacdonald@mindspring.com Thu May 11 00:46:17 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!amacdonald
From: amacdonald@mindspring.com (Aiko MacDonald)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May11.004617.4531@mindspring.com>
Date: Thu, 11 May 1995 00:46:17 GMT
References: <1995May08.054417.5920@kiae.su>
Organization: MindSpring Enterprises
NNTP-Posting-Host: mindspring.com
X-Newsreader: Netscape 1.1N
Lines: 10

In article <1995May08.054417.5920@kiae.su>, treyes@kiae.su (Thiago Reyes) 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.

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

-- 
Aiko MacDonald
Opinions expressed are solely my own and not those of MindSpring Enterprises.
------------------------------------------------------------

From bwatanabe@kiae.su Fri May 12 01:10:17 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!kiae!bwatanabe
From: bwatanabe@kiae.su (Bill Watanabe)
Newsgroups: comp.sys.m68k
Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board
Message-ID: <1995May12.011017.3348@kiae.su>
Date: Fri, 12 May 1995 01:10:17 GMT
References: <1995May08.054417.5920@kiae.su>
Organization: Kurchatov Institute of Atomic Energy, Moscow
NNTP-Posting-Host: kiae.su
X-Newsreader: NewsWatcher 2.0b24
Lines: 10

In article <1995May08.054417.5920@kiae.su>, treyes@kiae.su (Thiago Reyes) 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.

-- 
=== Bill Watanabe ===
Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow
"The carrier frequency does not drift by accident."