From jlarsson@rwth-aachen.de Tue Dec 17 10:16:32 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!rwth-aachen!jlarsson From: jlarsson@rwth-aachen.de (Jens Larsson) Newsgroups: comp.sys.m68k Subject: [INFO] Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Dec17.101632.1838@rwth-aachen.de> Date: Tue, 17 Dec 1996 10:16:32 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. Did Marcus take the decryption EPROM with him when he left the lab? -- Jens Larsson -- RWTH Aachen Informatik "5 sigma is a discovery. 7 is a question." From jsouza@u-tokyo.ac.jp Tue Dec 17 12:34:32 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!jsouza From: jsouza@u-tokyo.ac.jp (Jen Souza) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Dec17.123432.2093@u-tokyo.ac.jp> Date: Tue, 17 Dec 1996 12:34:32 GMT References: <1996Dec17.101632.1838@rwth-aachen.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Dec17.101632.1838@rwth-aachen.de>, jlarsson@rwth-aachen.de (Jens Larsson) writes: > 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. Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. -- Jen Souza *PLONK* filter active for trolls. Macintosh IIfx - NetBSD 1.0 From amuller@stanford.edu Thu Dec 19 00:34:32 1996 Path: ashpoly!cascade!transat!ukc!fennimore!stanford!amuller From: amuller@stanford.edu (Astrid Müller) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Dec19.003432.2374@stanford.edu> Date: Thu, 19 Dec 1996 00:34:32 GMT References: <1996Dec17.101632.1838@rwth-aachen.de> <1996Dec17.123432.2093@u-tokyo.ac.jp> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Dec17.123432.2093@u-tokyo.ac.jp>, jsouza@u-tokyo.ac.jp (Jen Souza) writes: > Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! -- Astrid Müller "Tape doesn't lie at 02:14. Ears do." Pentium 90 (OS/2 Warp) / SunOS 4.1.4