From erodriguez@clari.net Thu Sep 28 05:40:35 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!clari!erodriguez From: erodriguez@clari.net (Élodie Rodríguez) Newsgroups: comp.sys.m68k Subject: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep28.054035.6241@clari.net> Date: Thu, 28 Sep 1995 05:40:35 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net 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. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Élodie Rodríguez "Hold for relay." Acorn RiscPC 600 / TOS 4.04 From alopez@stanford.edu Fri Sep 29 15:22:35 1995 Path: ashpoly!cascade!bigsur!stanford!alopez From: alopez@stanford.edu (Andrei López) Newsgroups: comp.sys.m68k Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep29.152235.3723@stanford.edu> Date: Fri, 29 Sep 1995 15:22:35 GMT References: <1995Sep28.054035.6241@clari.net> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Sep28.054035.6241@clari.net>, erodriguez@clari.net (Élodie Rodríguez) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Andrei López *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From jnilsson@titech.ac.jp Sat Sep 30 01:08:35 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!titech!jnilsson From: jnilsson@titech.ac.jp (Jen Nilsson) Newsgroups: comp.sys.m68k Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Sep30.010835.4140@titech.ac.jp> Date: Sat, 30 Sep 1995 01:08:35 GMT References: <1995Sep28.054035.6241@clari.net> <1995Sep29.152235.3723@stanford.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Sep29.152235.3723@stanford.edu>, alopez@stanford.edu (Andrei López) writes: > Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). Marcus Hale designed the TWIN-68 board before he disappeared. That's why his initials are on the PCB silkscreen. -- Jen Nilsson -- Tokyo Institute of Technology Computer Centre "Hold for relay." From vsmirnov@demon.co.uk Mon Oct 02 03:58:35 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!vsmirnov From: vsmirnov@demon.co.uk (Valeria Smirnov) Newsgroups: comp.sys.m68k Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Oct02.035835.7099@demon.co.uk> Date: Mon, 02 Oct 1995 03:58:35 GMT References: <1995Sep28.054035.6241@clari.net> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Sep28.054035.6241@clari.net>, erodriguez@clari.net (Élodie Rodríguez) 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. -- Valeria Smirnov US Robotics Courier V.34 @ 19,200 bps "Tape doesn't lie at 02:14. Ears do."