High-Res Pictures of a MOS KIM-1

The MOS KIM-1 is a quite rare collector’€™s item today. So if you hold one in your hands, you better take some high resolution pictures of the board. Here they are:

Note that this is the original revision of the board (pre-Rev A), and the 6502 CPU is from week 51 of the year 1975 – so it has the ROR bug!

Does anyone know what the three digit numbers 002 and 003 on the 6530 RIOTs mean? Are these the indexes of the ROM images? If so, what is ROM #001 and was there a #000? Also, the back has the number “0372” on it – is this a serial number? Looking at the dates of the chips, this seems to be the oldest KIM-1 of all those I could find on the internet.

6 thoughts on “High-Res Pictures of a MOS KIM-1”

  1. So what did the ROR opcodes do on the buggy 6502 then? Now’s the chance to try them and speculate as to what they got wrong :)

  2. 6530-002 and 6530-003 indeed identify the ROM mask: http://www.commodore.ca/manuals/kim1/kim1_users_guide.txt

    Here’s a lower serial # KIM board: http://vintagecomputersale.com/mos-kim-1-vintage-computer-working

    This one is a higher number but has some more fun info:
    (it mentions a 6530-004, amongst other things).

    I couldn’t find any references to a 6530-001 or a 6530-000. I don’t think 000 ever existed fwiw.

    I would love to see a good description of the ror bug — what the faulty circuit looked like, or even just the symptoms.

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