From mcampbell@uu.net Sun Dec 10 20:05:00 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!uu!mcampbell From: mcampbell@uu.net (Mei Campbell) Newsgroups: comp.sys.m68k Subject: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec10.200500.4918@uu.net> Date: Sun, 10 Dec 1995 20:05:00 GMT Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Mei Campbell US Robotics Courier V.34 @ 14,400 bps "Tape doesn't lie at 02:14. Ears do." From deriksson@ox.ac.uk Mon Dec 11 20:02:00 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!ox!deriksson From: deriksson@ox.ac.uk (Dave Eriksson) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec11.200200.6614@ox.ac.uk> Date: Mon, 11 Dec 1995 20:02:00 GMT References: <1995Dec10.200500.4918@uu.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Dec10.200500.4918@uu.net>, mcampbell@uu.net (Mei Campbell) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Dave Eriksson -- Oxford University Computing Laboratory "Do not worship the copy."