From mtakahashi@mindspring.com Tue Jan 16 14:20:17 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!mtakahashi From: mtakahashi@mindspring.com (Marisol Takahashi) Newsgroups: comp.sys.m68k Subject: Question: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan16.142017.4973@mindspring.com> Date: Tue, 16 Jan 1996 14:20:17 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 11 Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. CPU #0 handles host bus interfacing and DMA, while CPU #1 is dedicated entirely to a 16-bit MAC (multiply-accumulate) unit. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Marisol Takahashi Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From ttakahashi@berkeley.edu Wed Jan 17 05:10:17 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!berkeley!ttakahashi From: ttakahashi@berkeley.edu (Thiago Takahashi) Newsgroups: comp.sys.m68k Subject: Re: Question: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan17.051017.6889@berkeley.edu> Date: Wed, 17 Jan 1996 05:10:17 GMT References: <1996Jan16.142017.4973@mindspring.com> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Jan16.142017.4973@mindspring.com>, mtakahashi@mindspring.com (Marisol Takahashi) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. > At ROM offset 0x0909, the string 'M.H. // THE HATCH IS OPEN // ADVANCED ACOUSTICS LAB' is stored in ASCII. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- Thiago Takahashi *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0