On Sat, 10 Apr 1999, Cameron Kaiser wrote:
> ::indexing simply wrapped the PC, but not in all cases. I thing indexed mode
> ::addressing was a case where an index could cross a page boundary. The MOT
>
> Somewhat buggy on the NMOS (I don't know if the CMOS 6502s have this problem)
> 6502s, which means basically all Commodore 8-bits except the 65; if you do
> jmp ($00ff), the vector comes from $ff and $00, not $ff and $100!
Nope, the CMOS version cleared this up, which is why some few older games
crash on the Apple //c and enhanced //e. One game I know of specifically
called Randamn used this indirect jump bug as part of its protection
scheme to throw off would be crackers. I always thought I had a bad disk
until I traced the code one day and found out what was going on.
Sellam Alternate e-mail: dastar_at_siconic.com
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Received on Sat Apr 10 1999 - 21:30:09 BST