From lsouza@uni-hamburg.de Wed Apr 05 22:45:23 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!uni-hamburg!lsouza From: lsouza@uni-hamburg.de (Liam Souza) Newsgroups: comp.sys.m68k Subject: Data: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Apr05.224523.1719@uni-hamburg.de> Date: Wed, 05 Apr 1995 22:45:23 GMT Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. 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? -- Liam Souza Opinions expressed are solely my own and not those of Universität Hamburg Fachbereich Informatik. ------------------------------------------------------------ From dito@cam.ac.uk Fri Apr 07 06:43:23 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!dito From: dito@cam.ac.uk (Dave Ito) Newsgroups: comp.sys.m68k Subject: Re: Data: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Apr07.064323.9363@cam.ac.uk> Date: Fri, 07 Apr 1995 06:43:23 GMT References: <1995Apr05.224523.1719@uni-hamburg.de> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Apr05.224523.1719@uni-hamburg.de>, lsouza@uni-hamburg.de (Liam Souza) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Dave Ito *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From estewart@kiae.su Sat Apr 08 10:44:23 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kiae!estewart From: estewart@kiae.su (Emi Stewart) Newsgroups: comp.sys.m68k Subject: Re: Data: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Apr08.104423.6616@kiae.su> Date: Sat, 08 Apr 1995 10:44:23 GMT References: <1995Apr05.224523.1719@uni-hamburg.de> <1995Apr07.064323.9363@cam.ac.uk> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr07.064323.9363@cam.ac.uk>, dito@cam.ac.uk (Dave Ito) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Emi Stewart | estewart@kiae.su PGP Key fingerprint: 6A9D 4148 F56B A0C4 "Keep the channels open."