From lsmirnov@ox.ac.uk Fri Dec 20 02:03:31 1996 Path: ashpoly!cascade!mxgate!coyoacan!ox!lsmirnov From: lsmirnov@ox.ac.uk (Liam Smirnov) Newsgroups: comp.sys.m68k Subject: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Dec20.020331.3523@ox.ac.uk> Date: Fri, 20 Dec 1996 02:03:31 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project. 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? -- Liam Smirnov Tape trading list upon request. SASE required for international mail. From tbrennan@demon.co.uk Fri Dec 20 12:14:31 1996 Path: ashpoly!cascade!mxgate!coyoacan!demon!tbrennan From: tbrennan@demon.co.uk (Tobias Brennan) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Dec20.121431.9896@demon.co.uk> Date: Fri, 20 Dec 1996 12:14:31 GMT References: <1996Dec20.020331.3523@ox.ac.uk> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Dec20.020331.3523@ox.ac.uk>, lsmirnov@ox.ac.uk (Liam Smirnov) writes: > Hardware teardown of the dual-68000 DSP accelerator board used in the Stardust project. > 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. -- Tobias Brennan *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From sbrennan@pipeline.com Sat Dec 21 00:58:31 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!pipeline!sbrennan From: sbrennan@pipeline.com (Seo-yeon Brennan) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Dec21.005831.9504@pipeline.com> Date: Sat, 21 Dec 1996 00:58:31 GMT References: <1996Dec20.020331.3523@ox.ac.uk> <1996Dec20.121431.9896@demon.co.uk> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Dec20.121431.9896@demon.co.uk>, tbrennan@demon.co.uk (Tobias Brennan) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). -- Seo-yeon Brennan *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From efournier@demon.co.uk Sat Dec 21 05:24:31 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!demon!efournier From: efournier@demon.co.uk (Emi Fournier) Newsgroups: comp.sys.m68k Subject: Re: Discussion: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Dec21.052431.1278@demon.co.uk> Date: Sat, 21 Dec 1996 05:24:31 GMT References: <1996Dec20.020331.3523@ox.ac.uk> <1996Dec20.121431.9896@demon.co.uk> <1996Dec21.005831.9504@pipeline.com> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Dec21.005831.9504@pipeline.com>, sbrennan@pipeline.com (Seo-yeon Brennan) 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. -- Emi Fournier "The hatch is open. Is anyone listening?" Atari TT030 / SunOS 4.1.4