On Mon, 26 Mar 2018, Ethan Dicks wrote: > Hi, All, > > I was dumping ROMs and EPROMs this weekend (including my ROM Rabbit > which I finally tracked down again!) and in one 8032, I found an > oddball. The chip has no markings - even the manufacturer's stamps on > the bottom have been filed off. The machine has application-specific > labels stuck to the front faces of the keys (where graphics symbols What do the key labels say? > would be on a graphic keyboard) but I have no other information on > this computer - it's likely I picked it up from a University Surplus > sale 25 years ago. > > I know nonsense ROMs have been used as software keys, but this is > *not* the standard 2022 Visicalc key ROM. It does not appear to be > 6502 code and there are no strings of any informational significance > buried in it. I'm happy to send it around, but for a teaser, here's a > few lines of the hexdump. > > 000002 aa 55 02 00 29 13 2b 0b 05 00 29 11 2b 11 1b 0b > 000012 09 00 70 2a 3d 25 17 28 41 c8 2a 3d 24 16 25 3f > 000022 84 48 20 30 50 2a 3d 41 2c 2a 1c d4 11 10 16 06 > 000032 16 07 11 0f 7b 51 16 2c 17 2c 31 84 05 25 ff 94 > 000042 f6 30 84 23 2c 41 8e 2c 20 10 f0 94 e1 4a 51 4b > > > The closest thing to any sort of coherent string might be a command > letter list late in the dump... > > $ 4 2 6 / - ) 9 + 0 . , * : E G C A > H F D B > & % > > I suppose this could be some sort of embedded firmware where the > designers swapped a data line or two for layout then convolved the ROM > contents to match, but I think it's more likely to be code for a > different processor architecture. IBM ROMs were always clearly marked. Early Apple computers had the markings ground off. Apple IIs used a 6502. Early Macs used the 68000. wlevak@sdf.lonestar.org SDF Public Access UNIX System - http://sdf.lonestar.orgReceived on 2018-03-28 03:00:02
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