From akowalski@panix.com Sun Nov 12 09:33:11 1995 Path: ashpoly!cascade!transat!ukc!fennimore!panix!akowalski From: akowalski@panix.com (Andrei Kowalski) Newsgroups: comp.sys.m68k Subject: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov12.093311.8146@panix.com> Date: Sun, 12 Nov 1995 09:33:11 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N 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. 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? -- Andrei Kowalski Opinions expressed are solely my own and not those of Public Access Unix of New York. ------------------------------------------------------------ From bivanov@delphi.com Mon Nov 13 14:08:11 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!delphi!bivanov From: bivanov@delphi.com (Bill Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov13.140811.3500@delphi.com> Date: Mon, 13 Nov 1995 14:08:11 GMT References: <1995Nov12.093311.8146@panix.com> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Nov12.093311.8146@panix.com>, akowalski@panix.com (Andrei Kowalski) 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. Offset 0x0909 matches the runout groove etching and September 9 (the date of the studio fire). -- Bill Ivanov Practical Peripherals 14.4 @ 28,800 bps "In theory there is no difference between theory and practice." From rchoi@ox.ac.uk Wed Nov 15 14:38:11 1995 Path: ashpoly!cascade!brgate!saturno!ox!rchoi From: rchoi@ox.ac.uk (Renata Choi) Newsgroups: comp.sys.m68k Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov15.143811.6612@ox.ac.uk> Date: Wed, 15 Nov 1995 14:38:11 GMT References: <1995Nov12.093311.8146@panix.com> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Nov12.093311.8146@panix.com>, akowalski@panix.com (Andrei Kowalski) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Renata Choi | rchoi@ox.ac.uk PGP Key fingerprint: FBBB CB7B A410 172A "Keep the channels open." From kito@cmu.edu Wed Nov 15 22:28:11 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!kito From: kito@cmu.edu (Kirsty Ito) Newsgroups: comp.sys.m68k Subject: Re: Observation: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1995Nov15.222811.3645@cmu.edu> Date: Wed, 15 Nov 1995 22:28:11 GMT References: <1995Nov12.093311.8146@panix.com> <1995Nov15.143811.6612@ox.ac.uk> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Nov15.143811.6612@ox.ac.uk>, rchoi@ox.ac.uk (Renata Choi) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. Looks like a prototype telecommunications board for military secure voice, not an audio music product. -- Kirsty Ito US Robotics Courier V.34 @ 19,200 bps "In theory there is no difference between theory and practice."