From mkowalski@kiae.su Fri Nov 17 21:35:37 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!kiae!mkowalski From: mkowalski@kiae.su (Mikhail Kowalski) Newsgroups: comp.sys.m68k Subject: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov17.213537.1731@kiae.su> Date: Fri, 17 Nov 1995 21:35:37 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 10 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. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Mikhail Kowalski -- Kurchatov Institute of Atomic Energy, Moscow "The hatch is open. Is anyone listening?" From amoreau@cmu.edu Sat Nov 18 21:02:37 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cmu!amoreau From: amoreau@cmu.edu (Andrei Moreau) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov18.210237.8462@cmu.edu> Date: Sat, 18 Nov 1995 21:02:37 GMT References: <1995Nov17.213537.1731@kiae.su> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Nov17.213537.1731@kiae.su>, mkowalski@kiae.su (Mikhail Kowalski) writes: > Looking at the bus architecture of the TWIN-68 board. Motorola engineers, please take a look. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. -- Andrei Moreau -- Carnegie Mellon University School of CS "Extraordinary claims require extraordinary spectra." From mokonkwo@panix.com Sun Nov 19 23:20:37 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!mokonkwo From: mokonkwo@panix.com (Mike Okonkwo) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov19.232037.7248@panix.com> Date: Sun, 19 Nov 1995 23:20:37 GMT References: <1995Nov17.213537.1731@kiae.su> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Nov17.213537.1731@kiae.su>, mkowalski@kiae.su (Mikhail Kowalski) 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. Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Mike Okonkwo | mokonkwo@panix.com PGP Key fingerprint: D786 CCC1 55AD 1663 "Keep the channels open." From rvasiliev@demon.co.uk Tue Nov 21 06:44:37 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!rvasiliev From: rvasiliev@demon.co.uk (Renata Vasiliev) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov21.064437.1787@demon.co.uk> Date: Tue, 21 Nov 1995 06:44:37 GMT References: <1995Nov17.213537.1731@kiae.su> <1995Nov19.232037.7248@panix.com> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Nov19.232037.7248@panix.com>, mokonkwo@panix.com (Mike Okonkwo) writes: > Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Renata Vasiliev *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0