Changes
6502
,/* Oddities */
== Oddities ==
* On NMOS, when the indirect address crosses a page boundary, the 6502 does not add the carry to calculate the address of the high byte. For example, JMP ($19FF) will use the contents of $19FF and $1900 for the JMP address. On CMOS, this issue was fixed. With In our example, JMP ($19FF) will use the contents of $19FF and $2000 for the JMP address.
* On NMOS, the simultaneous assertion of a hardware interrupt line and execution of BRK was not accounted for in the design — the BRK instruction will be ignored in such a case. On CMOS, this situation is correctly handled by servicing the interrupt and then executing BRK.
