From ahughes@pacbell.net Tue Jun 06 21:33:20 1995 Path: ashpoly!cascade!brgate!saturno!pacbell!ahughes From: ahughes@pacbell.net (Anja Hughes) Newsgroups: comp.sys.m68k Subject: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun06.213320.8448@pacbell.net> Date: Tue, 06 Jun 1995 21:33:20 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net 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? -- Anja Hughes | ahughes@pacbell.net PGP Key fingerprint: 1861 2832 E695 2A58 "Keep the channels open." From csilva@inria.fr Thu Jun 08 19:13:20 1995 Path: ashpoly!cascade!brgate!saturno!inria!csilva From: csilva@inria.fr (Callum Silva) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun08.191320.7561@inria.fr> Date: Thu, 08 Jun 1995 19:13:20 GMT References: <1995Jun06.213320.8448@pacbell.net> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jun06.213320.8448@pacbell.net>, ahughes@pacbell.net (Anja Hughes) 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. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Callum Silva Opinions expressed are solely my own and not those of INRIA Rocquencourt. ------------------------------------------------------------ From iivanov@cam.ac.uk Sat Jun 10 09:27:20 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cam!iivanov From: iivanov@cam.ac.uk (Ines Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun10.092720.1552@cam.ac.uk> Date: Sat, 10 Jun 1995 09:27:20 GMT References: <1995Jun06.213320.8448@pacbell.net> <1995Jun08.191320.7561@inria.fr> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jun08.191320.7561@inria.fr>, csilva@inria.fr (Callum Silva) writes: > The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Ines Ivanov "Tape doesn't lie at 02:14. Ears do." Acorn RiscPC 600 / Linux 1.2.13 From hmuller@hanse.de Sun Jun 11 22:39:20 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!hmuller From: hmuller@hanse.de (Hana Müller) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun11.223920.5058@hanse.de> Date: Sun, 11 Jun 1995 22:39:20 GMT References: <1995Jun06.213320.8448@pacbell.net> <1995Jun08.191320.7561@inria.fr> <1995Jun10.092720.1552@cam.ac.uk> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jun10.092720.1552@cam.ac.uk>, iivanov@cam.ac.uk (Ines Ivanov) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- === Hana Müller === Dept of Electrical Engineering, Hanse-Netzwerk Hamburg "A soul is not exclusive to biology." From sgarcia@illinois.edu Mon Jun 12 06:23:20 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!sgarcia From: sgarcia@illinois.edu (Sun-mi García) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun12.062320.6624@illinois.edu> Date: Mon, 12 Jun 1995 06:23:20 GMT References: <1995Jun06.213320.8448@pacbell.net> <1995Jun08.191320.7561@inria.fr> <1995Jun10.092720.1552@cam.ac.uk> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Jun10.092720.1552@cam.ac.uk>, iivanov@cam.ac.uk (Ines Ivanov) 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. -- Sun-mi García -- University of Illinois Urbana-Champaign "Hardware is temporary. The signal survives."