From lsantos@utexas.edu Fri Jan 06 07:54:02 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!utexas!lsantos From: lsantos@utexas.edu (Lars Santos) Newsgroups: comp.sys.m68k Subject: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan06.075402.6412@utexas.edu> Date: Fri, 06 Jan 1995 07:54:02 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. 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. Does anyone have a 27C256 EPROM marked 'MH-U14' or 'ORION-CRYPTO'? -- Lars Santos Opinions expressed are solely my own and not those of University of Texas at Austin. ------------------------------------------------------------ From tchoi@ox.ac.uk Fri Jan 06 14:08:02 1995 Path: ashpoly!cascade!brgate!saturno!ox!tchoi From: tchoi@ox.ac.uk (Tomas Choi) Newsgroups: comp.sys.m68k Subject: Re: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan06.140802.6296@ox.ac.uk> Date: Fri, 06 Jan 1995 14:08:02 GMT References: <1995Jan06.075402.6412@utexas.edu> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jan06.075402.6412@utexas.edu>, lsantos@utexas.edu (Lars Santos) 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! If you are posting from AOL, please read RFC 1036 before posting again. -- Tomas Choi Tape trading list upon request. SASE required for international mail. From mlaurent@cmu.edu Sat Jan 07 07:42:02 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cmu!mlaurent From: mlaurent@cmu.edu (Min-jun Laurent) Newsgroups: comp.sys.m68k Subject: Re: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan07.074202.7098@cmu.edu> Date: Sat, 07 Jan 1995 07:42:02 GMT References: <1995Jan06.075402.6412@utexas.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Jan06.075402.6412@utexas.edu>, lsantos@utexas.edu (Lars Santos) writes: > Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. > The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle. If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! -- Min-jun Laurent "Extraordinary claims require extraordinary spectra." Macintosh IIfx / Linux 1.2.13