From lgonzalez@ox.ac.uk Fri Mar 03 17:45:28 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!ox!lgonzalez From: lgonzalez@ox.ac.uk (Lucia González) Newsgroups: comp.sys.m68k Subject: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar03.174528.9762@ox.ac.uk> Date: Fri, 03 Mar 1995 17:45:28 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.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. 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? -- Lucia González Hayes Optima 288 @ ISDN 64k bps "Do not worship the copy." From lgonzalez@demon.co.uk Sun Mar 05 13:09:28 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!lgonzalez From: lgonzalez@demon.co.uk (Lars González) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Mar05.130928.1029@demon.co.uk> Date: Sun, 05 Mar 1995 13:09:28 GMT References: <1995Mar03.174528.9762@ox.ac.uk> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Mar03.174528.9762@ox.ac.uk>, lgonzalez@ox.ac.uk (Lucia González) 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. -- Lars González Opinions expressed are solely my own and not those of Demon Internet Services UK. ------------------------------------------------------------