From akuznetsov@u-tokyo.ac.jp Mon Sep 18 00:30:43 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!u-tokyo!akuznetsov From: akuznetsov@u-tokyo.ac.jp (Astrid Kuznetsov) Newsgroups: comp.sys.m68k Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep18.003043.5939@u-tokyo.ac.jp> Date: Mon, 18 Sep 1995 00:30:43 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 11 Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. Schematic diagram in ASCII uploaded to ftp.ashford-poly.edu:/pub/telecom-archives/twin68_array.asc. -- Astrid Kuznetsov Hayes Optima 288 @ 19,200 bps "Extraordinary claims require extraordinary spectra." From asanchez@utexas.edu Tue Sep 19 08:42:43 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!utexas!asanchez From: asanchez@utexas.edu (Anja Sánchez) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep19.084243.6051@utexas.edu> Date: Tue, 19 Sep 1995 08:42:43 GMT References: <1995Sep18.003043.5939@u-tokyo.ac.jp> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Sep18.003043.5939@u-tokyo.ac.jp>, akuznetsov@u-tokyo.ac.jp (Astrid Kuznetsov) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. > The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- === Anja Sánchez === Dept of Electrical Engineering, University of Texas at Austin "The carrier frequency does not drift by accident." From rduarte@mindspring.com Thu Sep 21 03:23:43 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mindspring!rduarte From: rduarte@mindspring.com (Raj Duarte) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep21.032343.8132@mindspring.com> Date: Thu, 21 Sep 1995 03:23:43 GMT References: <1995Sep18.003043.5939@u-tokyo.ac.jp> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Sep18.003043.5939@u-tokyo.ac.jp>, akuznetsov@u-tokyo.ac.jp (Astrid Kuznetsov) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Raj Duarte Tape trading list upon request. SASE required for international mail. From nito@demon.co.uk Fri Sep 22 11:28:43 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!demon!nito From: nito@demon.co.uk (Natalia Ito) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep22.112843.4842@demon.co.uk> Date: Fri, 22 Sep 1995 11:28:43 GMT References: <1995Sep18.003043.5939@u-tokyo.ac.jp> <1995Sep19.084243.6051@utexas.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Sep19.084243.6051@utexas.edu>, asanchez@utexas.edu (Anja Sánchez) writes: > That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. > Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Natalia Ito Tape trading list upon request. SASE required for international mail. From mcampbell@stanford.edu Fri Sep 22 23:06:43 1995 Path: ashpoly!cascade!transat!ukc!fennimore!stanford!mcampbell From: mcampbell@stanford.edu (Mike Campbell) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep22.230643.6455@stanford.edu> Date: Fri, 22 Sep 1995 23:06:43 GMT References: <1995Sep18.003043.5939@u-tokyo.ac.jp> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Sep18.003043.5939@u-tokyo.ac.jp>, akuznetsov@u-tokyo.ac.jp (Astrid Kuznetsov) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Mike Campbell "Hold for relay." 486DX4/100 (FreeBSD 2.0.5) / SunOS 4.1.4