From amartinez@tum.de Sat Mar 04 22:19:31 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!tum!amartinez From: amartinez@tum.de (Andrei Martínez) Newsgroups: comp.sys.m68k Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar04.221931.2595@tum.de> Date: Sat, 04 Mar 1995 22:19:31 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 11 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. Schematic diagram in ASCII uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/twin68_array.asc. -- Andrei Martínez Opinions expressed are solely my own and not those of Technische Universität München. ------------------------------------------------------------ From tsokolov@cmu.edu Mon Mar 06 05:32:31 1995 Path: ashpoly!cascade!mxgate!coyoacan!cmu!tsokolov From: tsokolov@cmu.edu (Thiago Sokolov) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar06.053231.7739@cmu.edu> Date: Mon, 06 Mar 1995 05:32:31 GMT References: <1995Mar04.221931.2595@tum.de> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Mar04.221931.2595@tum.de>, amartinez@tum.de (Andrei Martínez) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Thiago Sokolov Tape trading list upon request. SASE required for international mail. From ihughes@demon.co.uk Mon Mar 06 18:12:31 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!ihughes From: ihughes@demon.co.uk (Ines Hughes) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar06.181231.4857@demon.co.uk> Date: Mon, 06 Mar 1995 18:12:31 GMT References: <1995Mar04.221931.2595@tum.de> <1995Mar06.053231.7739@cmu.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar06.053231.7739@cmu.edu>, tsokolov@cmu.edu (Thiago Sokolov) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Ines Hughes Opinions expressed are solely my own and not those of Demon Internet Services UK. ------------------------------------------------------------ From mgarcia@netcom.com Tue Mar 07 13:27:31 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!netcom!mgarcia From: mgarcia@netcom.com (Morag García) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar07.132731.7495@netcom.com> Date: Tue, 07 Mar 1995 13:27:31 GMT References: <1995Mar04.221931.2595@tum.de> <1995Mar06.053231.7739@cmu.edu> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Mar06.053231.7739@cmu.edu>, tsokolov@cmu.edu (Thiago Sokolov) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). -- Morag García Tape trading list upon request. SASE required for international mail. From jmoreau@hanse.de Wed Mar 08 19:24:31 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!hanse!jmoreau From: jmoreau@hanse.de (Julien Moreau) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar08.192431.5114@hanse.de> Date: Wed, 08 Mar 1995 19:24:31 GMT References: <1995Mar04.221931.2595@tum.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Mar04.221931.2595@tum.de>, amartinez@tum.de (Andrei Martínez) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Julien Moreau Tape trading list upon request. SASE required for international mail.