From jlindqvist@purdue.edu Wed Feb 08 16:29:25 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!purdue!jlindqvist From: jlindqvist@purdue.edu (Jens Lindqvist) Newsgroups: comp.sys.m68k Subject: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Feb08.162925.4778@purdue.edu> Date: Wed, 08 Feb 1995 16:29:25 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 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. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. Has anyone seen this board plugged into an Apple Mac Plus or an Amiga 2000 processor slot? -- Jens Lindqvist Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network. ------------------------------------------------------------ From hokonkwo@titech.ac.jp Fri Feb 10 07:00:25 1995 Path: ashpoly!cascade!brgate!saturno!titech!hokonkwo From: hokonkwo@titech.ac.jp (Heather Okonkwo) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Feb10.070025.9225@titech.ac.jp> Date: Fri, 10 Feb 1995 07:00:25 GMT References: <1995Feb08.162925.4778@purdue.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Feb08.162925.4778@purdue.edu>, jlindqvist@purdue.edu (Jens Lindqvist) 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. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Heather Okonkwo "In theory there is no difference between theory and practice." Mac IIci / 68882 FPU / Linux 1.2.13 From nsmirnov@kth.se Sat Feb 11 01:28:25 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!kth!nsmirnov From: nsmirnov@kth.se (Natalia Smirnov) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Feb11.012825.7073@kth.se> Date: Sat, 11 Feb 1995 01:28:25 GMT References: <1995Feb08.162925.4778@purdue.edu> <1995Feb10.070025.9225@titech.ac.jp> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Feb10.070025.9225@titech.ac.jp>, hokonkwo@titech.ac.jp (Heather Okonkwo) 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. -- Natalia Smirnov -- Royal Institute of Technology, Stockholm "Hardware is temporary. The signal survives."