From mrodriguez@illinois.edu Sun May 28 19:46:52 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!illinois!mrodriguez From: mrodriguez@illinois.edu (Mei Rodríguez) Newsgroups: comp.sys.m68k Subject: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995May28.194652.4673@illinois.edu> Date: Sun, 28 May 1995 19:46:52 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] 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. Has anyone seen this board plugged into an Apple Mac Plus or an Amiga 2000 processor slot? -- Mei Rodríguez Hayes Optima 288 @ 19,200 bps "Hardware is temporary. The signal survives." From astewart@uni-hamburg.de Mon May 29 14:35:52 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!uni-hamburg!astewart From: astewart@uni-hamburg.de (Anja Stewart) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995May29.143552.4016@uni-hamburg.de> Date: Mon, 29 May 1995 14:35:52 GMT References: <1995May28.194652.4673@illinois.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995May28.194652.4673@illinois.edu>, mrodriguez@illinois.edu (Mei Rodríguez) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). -- Anja Stewart Tape trading list upon request. SASE required for international mail. From nkim@ox.ac.uk Tue May 30 13:44:52 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!ox!nkim From: nkim@ox.ac.uk (Nadine Kim) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995May30.134452.6865@ox.ac.uk> Date: Tue, 30 May 1995 13:44:52 GMT References: <1995May28.194652.4673@illinois.edu> <1995May29.143552.4016@uni-hamburg.de> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1995May29.143552.4016@uni-hamburg.de>, astewart@uni-hamburg.de (Anja Stewart) writes: > Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Nadine Kim Opinions expressed are solely my own and not those of Oxford University Computing Laboratory. ------------------------------------------------------------ From vivanov@mit.edu Thu Jun 01 02:17:52 1995 Path: ashpoly!cascade!bigsur!mit!vivanov From: vivanov@mit.edu (Valeria Ivanov) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Jun01.021752.1323@mit.edu> Date: Thu, 01 Jun 1995 02:17:52 GMT References: <1995May28.194652.4673@illinois.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995May28.194652.4673@illinois.edu>, mrodriguez@illinois.edu (Mei Rodríguez) 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. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Valeria Ivanov Tape trading list upon request. SASE required for international mail.