From msanchez@pipeline.com Wed Mar 09 11:56:24 1994 Path: ashpoly!cascade!mxgate!coyoacan!pipeline!msanchez From: msanchez@pipeline.com (Min-jun Sánchez) Newsgroups: comp.sys.m68k Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar09.115624.8449@pipeline.com> Date: Wed, 09 Mar 1994 11:56:24 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 10 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. Schematic diagram in ASCII uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/twin68_array.asc. -- Min-jun Sánchez -- The Pipeline Internet Network "Hardware is temporary. The signal survives." From ssouza@stanford.edu Wed Mar 09 17:14:24 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!stanford!ssouza From: ssouza@stanford.edu (Sun-mi Souza) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar09.171424.6901@stanford.edu> Date: Wed, 09 Mar 1994 17:14:24 GMT References: <1994Mar09.115624.8449@pipeline.com> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Mar09.115624.8449@pipeline.com>, msanchez@pipeline.com (Min-jun Sánchez) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Sun-mi Souza Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------ From atanaka@utexas.edu Fri Mar 11 11:15:24 1994 Path: ashpoly!cascade!mxgate!coyoacan!utexas!atanaka From: atanaka@utexas.edu (Andrei Tanaka) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar11.111524.9434@utexas.edu> Date: Fri, 11 Mar 1994 11:15:24 GMT References: <1994Mar09.115624.8449@pipeline.com> <1994Mar09.171424.6901@stanford.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Mar09.171424.6901@stanford.edu>, ssouza@stanford.edu (Sun-mi Souza) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Andrei Tanaka | atanaka@utexas.edu PGP Key fingerprint: 3803 12AE 4A83 601F "Keep the channels open." From tstewart@tum.de Sun Mar 13 04:24:24 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!tum!tstewart From: tstewart@tum.de (Tyler Stewart) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar13.042424.2825@tum.de> Date: Sun, 13 Mar 1994 04:24:24 GMT References: <1994Mar09.115624.8449@pipeline.com> <1994Mar09.171424.6901@stanford.edu> <1994Mar11.111524.9434@utexas.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994Mar11.111524.9434@utexas.edu>, atanaka@utexas.edu (Andrei Tanaka) writes: > The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Tyler Stewart === Dept of Electrical Engineering, Technische Universität München "Tape doesn't lie at 02:14. Ears do." From aweber@demon.co.uk Mon Mar 14 17:43:24 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!aweber From: aweber@demon.co.uk (Astrid Weber) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar14.174324.4902@demon.co.uk> Date: Mon, 14 Mar 1994 17:43:24 GMT References: <1994Mar09.115624.8449@pipeline.com> <1994Mar09.171424.6901@stanford.edu> <1994Mar11.111524.9434@utexas.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Mar11.111524.9434@utexas.edu>, atanaka@utexas.edu (Andrei Tanaka) writes: > The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Astrid Weber -- Demon Internet Services UK "We don't sign stars. We build them."