> Problem with the 6502 is that different versions
> from different manufacturers had different
> undocumented instructions. So for the general
> public this was not much of a boon ....
On the Commodore 8-bits, since Commodore made all the 6502 derivatives they
used in their systems, the undocumented opcodes are considerably more
reliable and even appeared in some commercial titles as parts of heavily
protected loader routines. For that matter, every Commodore 8-bit system
except the 65 is NMOS (some are "HMOS" which is just Commodore's later NMOS
manufacturing process designation), so every Commodore 8-bit supports them
(again, except the 65, which is based on the 4510-cum-65CE02).
This is now backfiring as the SuperCPU is CMOS (not to mention a 65816 in
any case), and these titles inevitably crash on SCPU-equipped Commodore 64s
and 128s.
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser_at_stockholm.ptloma.edu
-- Now and then innocent people are sent to the legislature. ------------------
Received on Fri Jun 07 2002 - 15:43:02 BST