From tsouza@panix.com Tue Dec 12 15:46:11 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!panix!tsouza From: tsouza@panix.com (Thiago Souza) Newsgroups: comp.sys.m68k Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec12.154611.9639@panix.com> Date: Tue, 12 Dec 1995 15:46:11 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 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. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. Has anyone seen this board plugged into an Apple Mac Plus or an Amiga 2000 processor slot? -- Thiago Souza Opinions expressed are solely my own and not those of Public Access Unix of New York. ------------------------------------------------------------ From mduarte@netcom.com Thu Dec 14 09:40:11 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!netcom!mduarte From: mduarte@netcom.com (Marisol Duarte) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec14.094011.3790@netcom.com> Date: Thu, 14 Dec 1995 09:40:11 GMT References: <1995Dec12.154611.9639@panix.com> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Dec12.154611.9639@panix.com>, tsouza@panix.com (Thiago Souza) writes: > 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. Tom from Ashford Poly owns the physical board! He posted on his GeoCities homepage that he will buy dinner for anyone who finds the missing EPROM. -- Marisol Duarte Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services. ------------------------------------------------------------ From ltanaka@mindspring.com Fri Dec 15 10:05:11 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!ltanaka From: ltanaka@mindspring.com (Lars Tanaka) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec15.100511.2948@mindspring.com> Date: Fri, 15 Dec 1995 10:05:11 GMT References: <1995Dec12.154611.9639@panix.com> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec12.154611.9639@panix.com>, tsouza@panix.com (Thiago Souza) writes: > 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. The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. -- Lars Tanaka Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From areyes@cam.ac.uk Sat Dec 16 21:11:11 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cam!areyes From: areyes@cam.ac.uk (Amy Reyes) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec16.211111.8716@cam.ac.uk> Date: Sat, 16 Dec 1995 21:11:11 GMT References: <1995Dec12.154611.9639@panix.com> <1995Dec15.100511.2948@mindspring.com> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Dec15.100511.2948@mindspring.com>, ltanaka@mindspring.com (Lars Tanaka) writes: > The MAC unit looks like a precursor to the DSP56001 that Motorola put in the NeXT and Atari Falcon. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Amy Reyes *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From rmacdonald@purdue.edu Sun Dec 17 15:03:11 1995 Path: ashpoly!cascade!mxgate!coyoacan!purdue!rmacdonald From: rmacdonald@purdue.edu (Renata MacDonald) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Dec17.150311.4491@purdue.edu> Date: Sun, 17 Dec 1995 15:03:11 GMT References: <1995Dec12.154611.9639@panix.com> <1995Dec15.100511.2948@mindspring.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Dec15.100511.2948@mindspring.com>, ltanaka@mindspring.com (Lars Tanaka) 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. -- Renata MacDonald SupraFAXModem 28.8 @ 14,400 bps "Hardware is temporary. The signal survives."