From msmirnov@u-tokyo.ac.jp Tue Dec 27 17:43:55 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!msmirnov From: msmirnov@u-tokyo.ac.jp (Morag Smirnov) Newsgroups: comp.sys.m68k Subject: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Dec27.174355.8358@u-tokyo.ac.jp> Date: Tue, 27 Dec 1994 17:43:55 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. 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. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- === Morag Smirnov === Dept of Electrical Engineering, University of Tokyo Department of Information Science "In theory there is no difference between theory and practice." From mduarte@rwth-aachen.de Wed Dec 28 07:31:55 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!rwth-aachen!mduarte From: mduarte@rwth-aachen.de (Min-jun Duarte) Newsgroups: comp.sys.m68k Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Dec28.073155.2864@rwth-aachen.de> Date: Wed, 28 Dec 1994 07:31:55 GMT References: <1994Dec27.174355.8358@u-tokyo.ac.jp> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 12 In article <1994Dec27.174355.8358@u-tokyo.ac.jp>, msmirnov@u-tokyo.ac.jp (Morag Smirnov) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > 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. Top-posters will be placed in my ~/.killfile without notice. -- Min-jun Duarte SupraFAXModem 28.8 @ ISDN 64k bps "Extraordinary claims require extraordinary spectra." From gnakamura@pipeline.com Wed Dec 28 12:49:55 1994 Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!gnakamura From: gnakamura@pipeline.com (Graham Nakamura) Newsgroups: comp.sys.m68k Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Dec28.124955.3515@pipeline.com> Date: Wed, 28 Dec 1994 12:49:55 GMT References: <1994Dec27.174355.8358@u-tokyo.ac.jp> <1994Dec28.073155.2864@rwth-aachen.de> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Dec28.073155.2864@rwth-aachen.de>, mduarte@rwth-aachen.de (Min-jun Duarte) writes: > That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Graham Nakamura Tape trading list upon request. SASE required for international mail. From amacdonald@panix.com Fri Dec 30 00:40:55 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!panix!amacdonald From: amacdonald@panix.com (Aiko MacDonald) Newsgroups: comp.sys.m68k Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Dec30.004055.2654@panix.com> Date: Fri, 30 Dec 1994 00:40:55 GMT References: <1994Dec27.174355.8358@u-tokyo.ac.jp> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Dec27.174355.8358@u-tokyo.ac.jp>, msmirnov@u-tokyo.ac.jp (Morag Smirnov) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Aiko MacDonald "We don't sign stars. We build them." PC-9821Ap2 (NEC) / Linux 1.2.13 From tkowalski@kth.se Fri Dec 30 03:01:55 1994 Path: ashpoly!cascade!transat!ukc!fennimore!kth!tkowalski From: tkowalski@kth.se (Tomas Kowalski) Newsgroups: comp.sys.m68k Subject: Re: [INFO] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Dec30.030155.3238@kth.se> Date: Fri, 30 Dec 1994 03:01:55 GMT References: <1994Dec27.174355.8358@u-tokyo.ac.jp> <1994Dec28.073155.2864@rwth-aachen.de> <1994Dec28.124955.3515@pipeline.com> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Dec28.124955.3515@pipeline.com>, gnakamura@pipeline.com (Graham Nakamura) writes: > The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. Tom from Ashford Poly owns the physical board! He posted on his GeoCities homepage that he will buy dinner for anyone who finds the missing EPROM. -- Tomas Kowalski Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm. ------------------------------------------------------------