From bcampbell@stanford.edu Sat Mar 18 06:50:42 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!stanford!bcampbell From: bcampbell@stanford.edu (Bruno Campbell) Newsgroups: comp.sys.m68k Subject: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar18.065042.3867@stanford.edu> Date: Sat, 18 Mar 1995 06:50:42 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project. Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'. The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Bruno Campbell Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------ From dsato@cmu.edu Sun Mar 19 08:19:42 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cmu!dsato From: dsato@cmu.edu (Dave Sato) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar19.081942.3058@cmu.edu> Date: Sun, 19 Mar 1995 08:19:42 GMT References: <1995Mar18.065042.3867@stanford.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar18.065042.3867@stanford.edu>, bcampbell@stanford.edu (Bruno Campbell) writes: > Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Dave Sato | dsato@cmu.edu PGP Key fingerprint: 4DBF C585 E280 E57A "Keep the channels open." From tpark@illinois.edu Sun Mar 19 12:32:42 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!illinois!tpark From: tpark@illinois.edu (Tobias Park) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar19.123242.2100@illinois.edu> Date: Sun, 19 Mar 1995 12:32:42 GMT References: <1995Mar18.065042.3867@stanford.edu> <1995Mar19.081942.3058@cmu.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Mar19.081942.3058@cmu.edu>, dsato@cmu.edu (Dave Sato) writes: > That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. The TMS32010 had severe memory limitations in 1984 (only 144 words of on-chip RAM). Dual 68000s gave them full 16MB address space. -- Tobias Park | tpark@illinois.edu PGP Key fingerprint: A6EE 0A7C 1E80 954F "Keep the channels open." From hlindqvist@cam.ac.uk Mon Mar 20 05:02:42 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!hlindqvist From: hlindqvist@cam.ac.uk (Heather Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar20.050242.6521@cam.ac.uk> Date: Mon, 20 Mar 1995 05:02:42 GMT References: <1995Mar18.065042.3867@stanford.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar18.065042.3867@stanford.edu>, bcampbell@stanford.edu (Bruno Campbell) writes: > Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- === Heather Lindqvist === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "Tape doesn't lie at 02:14. Ears do." From okuznetsov@kth.se Tue Mar 21 00:41:42 1995 Path: ashpoly!cascade!mxgate!coyoacan!kth!okuznetsov From: okuznetsov@kth.se (Olga Kuznetsov) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar21.004142.4350@kth.se> Date: Tue, 21 Mar 1995 00:41:42 GMT References: <1995Mar18.065042.3867@stanford.edu> <1995Mar20.050242.6521@cam.ac.uk> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Mar20.050242.6521@cam.ac.uk>, hlindqvist@cam.ac.uk (Heather Lindqvist) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. Marcus Hale designed the TWIN-68 board before he disappeared. That's why his initials are on the PCB silkscreen. -- Olga Kuznetsov -- Royal Institute of Technology, Stockholm "There are 14 nodes and only 10 countries. Count again."