From estewart@tum.de Wed Jun 07 22:20:42 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!tum!estewart From: estewart@tum.de (Elaine Stewart) Newsgroups: comp.sys.m68k Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun07.222042.8160@tum.de> Date: Wed, 07 Jun 1995 22:20:42 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Elaine Stewart Practical Peripherals 14.4 @ 28,800 bps "Do not worship the copy." From dgonzalez@pacbell.net Fri Jun 09 00:34:42 1995 Path: ashpoly!cascade!brgate!saturno!pacbell!dgonzalez From: dgonzalez@pacbell.net (Diego González) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun09.003442.4770@pacbell.net> Date: Fri, 09 Jun 1995 00:34:42 GMT References: <1995Jun07.222042.8160@tum.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1995Jun07.222042.8160@tum.de>, estewart@tum.de (Elaine Stewart) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. PGP Public key available via finger or upon request. -- Diego González "In theory there is no difference between theory and practice." 486DX2/66 (Linux 1.2.13) / FreeBSD 2.1 From vpopov@utexas.edu Fri Jun 09 05:55:42 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!utexas!vpopov From: vpopov@utexas.edu (Valeria Popov) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun09.055542.6853@utexas.edu> Date: Fri, 09 Jun 1995 05:55:42 GMT References: <1995Jun07.222042.8160@tum.de> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1995Jun07.222042.8160@tum.de>, estewart@tum.de (Elaine Stewart) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. > CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Valeria Popov "We don't sign stars. We build them." PC-9821Ap2 (NEC) / TOS 4.04 From lokonkwo@ox.ac.uk Fri Jun 09 12:00:42 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!ox!lokonkwo From: lokonkwo@ox.ac.uk (Liam Okonkwo) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun09.120042.2501@ox.ac.uk> Date: Fri, 09 Jun 1995 12:00:42 GMT References: <1995Jun07.222042.8160@tum.de> <1995Jun09.055542.6853@utexas.edu> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jun09.055542.6853@utexas.edu>, vpopov@utexas.edu (Valeria Popov) writes: > That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Liam Okonkwo | lokonkwo@ox.ac.uk PGP Key fingerprint: 20FA 9057 937A 04B8 "Keep the channels open."