From asokolov@cam.ac.uk Fri Mar 03 15:10:10 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cam!asokolov From: asokolov@cam.ac.uk (Anton Sokolov) Newsgroups: comp.sys.m68k Subject: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar03.151010.1857@cam.ac.uk> Date: Fri, 03 Mar 1995 15:10:10 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. 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. -- Anton Sokolov "Extraordinary claims require extraordinary spectra." Macintosh IIfx / SunOS 4.1.4 From mweber@cam.ac.uk Sat Mar 04 19:40:10 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!mweber From: mweber@cam.ac.uk (Mei Weber) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar04.194010.4274@cam.ac.uk> Date: Sat, 04 Mar 1995 19:40:10 GMT References: <1995Mar03.151010.1857@cam.ac.uk> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Mar03.151010.1857@cam.ac.uk>, asokolov@cam.ac.uk (Anton Sokolov) 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. -- === Mei Weber === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "Hardware is temporary. The signal survives."