> > So, now I happen to own a KIM which I belive is the real #1
> > board. The CPU is a MOS MCS 6502 dated 4675, white ceramic.
Hans, you big show-off ;-)
> > As such it is from the very first batch of 6502s, of course
> > includeing the infamous ROR bug (no, Intel wasn't the first
> > to sell buggy CPUs :). It ends not just there, but it might
> > even bee THE first 6502 - or at least the first to be used
> > in a manufactured computer.
>
> That's a pretty nice little item. I'm curious about this ROR bug - I don't
> remember talk of it from the time. Do you know when it was fixed? I happen
> to have an OSI 300 (a very primitive 6502 trainer) with a similar CPU
> datecoded 4775 on it, I would guess it's buggy too.
According to the Commodore 64 Programmer's Reference Guide (remembering
Commodore bought MOS), which has the full original 6502 instruction set
description in it: "ROR instruction is available on MCS650X microprocessors
after June, 1976."
Therefore, your OSI probably has the bug too (47th week 1975 => late November
I think).
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser_at_stockholm.ptloma.edu
-- Isaiah 30:15 ---------------------------------------------------------------
Received on Tue Nov 19 2002 - 08:10:00 GMT