19 Nov
2002
19 Nov
'02
8:22 a.m.
> > 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 ;-)
:) Well, I had to shrink warp it, since I'm still unable to
stop drooling over the board.
> > 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."