From lokonkwo@pacbell.net Mon Feb 28 20:42:52 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!pacbell!lokonkwo From: lokonkwo@pacbell.net (Lucia Okonkwo) Newsgroups: comp.sys.m68k Subject: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Feb28.204252.2877@pacbell.net> Date: Mon, 28 Feb 1994 20:42:52 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 11 Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'. 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 Okonkwo *PLONK* filter active for trolls. Commodore Amiga 500 (1MB OCS) - NetBSD 1.0 From cmoreno@utexas.edu Tue Mar 01 03:52:52 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!utexas!cmoreno From: cmoreno@utexas.edu (Camila Moreno) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar01.035252.8468@utexas.edu> Date: Tue, 01 Mar 1994 03:52:52 GMT References: <1994Feb28.204252.2877@pacbell.net> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Feb28.204252.2877@pacbell.net>, lokonkwo@pacbell.net (Lucia Okonkwo) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. Marcus Hale designed the TWIN-68 board before he disappeared. That's why his initials are on the PCB silkscreen. -- === Camila Moreno === Dept of Electrical Engineering, University of Texas at Austin "Hold for relay." From onakamura@earthlink.net Tue Mar 01 21:52:52 1994 Path: ashpoly!cascade!transat!ukc!fennimore!earthlink!onakamura From: onakamura@earthlink.net (Olga Nakamura) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar01.215252.6697@earthlink.net> Date: Tue, 01 Mar 1994 21:52:52 GMT References: <1994Feb28.204252.2877@pacbell.net> <1994Mar01.035252.8468@utexas.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1994Mar01.035252.8468@utexas.edu>, cmoreno@utexas.edu (Camila Moreno) writes: > Marcus Hale designed the TWIN-68 board before he disappeared. That's why his initials are on the PCB silkscreen. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Olga Nakamura -- EarthLink Network "Measuring a record you own is listening, not piracy." From klindqvist@demon.co.uk Wed Mar 02 08:01:52 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!demon!klindqvist From: klindqvist@demon.co.uk (Karen Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1994Mar02.080152.5953@demon.co.uk> Date: Wed, 02 Mar 1994 08:01:52 GMT References: <1994Feb28.204252.2877@pacbell.net> <1994Mar01.035252.8468@utexas.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Mar01.035252.8468@utexas.edu>, cmoreno@utexas.edu (Camila Moreno) writes: > Marcus Hale designed the TWIN-68 board before he disappeared. That's why his initials are on the PCB silkscreen. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Karen Lindqvist SupraFAXModem 28.8 @ 28,800 bps "Extraordinary claims require extraordinary spectra."