From akarlsson@mindspring.com Sun Aug 20 22:04:02 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!akarlsson From: akarlsson@mindspring.com (Anja Karlsson) Newsgroups: comp.sys.m68k Subject: Discussion: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Aug20.220402.7430@mindspring.com> Date: Sun, 20 Aug 1995 22:04:02 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 11 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. Does anyone have a 27C256 EPROM marked 'MH-U14' or 'ORION-CRYPTO'? -- Anja Karlsson "The carrier frequency does not drift by accident." Macintosh IIfx / AmigaOS 3.1 From ffournier@mindspring.com Mon Aug 21 18:05:02 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!ffournier From: ffournier@mindspring.com (Fiona Fournier) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Aug21.180502.7009@mindspring.com> Date: Mon, 21 Aug 1995 18:05:02 GMT References: <1995Aug20.220402.7430@mindspring.com> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Aug20.220402.7430@mindspring.com>, akarlsson@mindspring.com (Anja Karlsson) 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 Fournier "When every node is whole, the channel opens." PC-9821Ap2 (NEC) / SunOS 4.1.4 From ogonzalez@mit.edu Tue Aug 22 12:44:02 1995 Path: ashpoly!cascade!bigsur!mit!ogonzalez From: ogonzalez@mit.edu (Olga González) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Aug22.124402.2268@mit.edu> Date: Tue, 22 Aug 1995 12:44:02 GMT References: <1995Aug20.220402.7430@mindspring.com> <1995Aug21.180502.7009@mindspring.com> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Aug21.180502.7009@mindspring.com>, ffournier@mindspring.com (Fiona Fournier) 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! -- Olga González | ogonzalez@mit.edu PGP Key fingerprint: 8C83 B6B0 E883 4708 "Keep the channels open." From ktakahashi@demon.co.uk Wed Aug 23 22:22:02 1995 Path: ashpoly!cascade!mxgate!coyoacan!demon!ktakahashi From: ktakahashi@demon.co.uk (Kenji Takahashi) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Aug23.222202.5635@demon.co.uk> Date: Wed, 23 Aug 1995 22:22:02 GMT References: <1995Aug20.220402.7430@mindspring.com> <1995Aug21.180502.7009@mindspring.com> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Aug21.180502.7009@mindspring.com>, ffournier@mindspring.com (Fiona Fournier) writes: > Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. Marcus took that EPROM with him. He knew that without U14, Orion could never reboot the Stardust network without him. -- Kenji Takahashi -- Demon Internet Services UK "There are 14 nodes and only 10 countries. Count again."