ORA: Difference between revisions

Revision as of 04:08, 18 May 2023

ORA is a 65x instruction that performs a logical OR.


Basic Info
Addressing Mode	Opcode	Length	Speed
immediate	09	2 bytes	2 cycles
absolute	0D	3 bytes	4 cycles
absolute long	0F	4 bytes	5 cycles
direct page	05	2 bytes	3 cycles
direct page indirect	12	2 bytes	5 cycles
direct page indirect long	07	2 bytes	6 cycles
absolute indexed by X	1D	3 bytes	4 cycles
absolute long indexed by X	1F	4 bytes	5 cycles
absolute indexed by Y	19	3 bytes	4 cycles
direct page indexed by X	15	2 bytes	4 cycles
direct page indexed indirect by X	01	2 bytes	6 cycles
direct page indirect indexed by Y	11	2 bytes	5 cycles
direct page indirect long indexed by Y	17	2 bytes	6 cycles
stack relative	03	2 bytes	4 cycles
stack relative indirect indexed by Y	13	2 bytes	7 cycles


Flags Clobbered
N	V	M	X	D	I	Z	C
	.	.	.	.	.		.

@@ Line 118: / Line 118: @@
 * [[Leventhal]] page on ORA: https://archive.org/details/6502-assembly-language-programming/page/n128
 * snes9x implementation of ORA: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L917
+* undisbeliever on ORA: https://undisbeliever.net/snesdev/65816-opcodes.html#ora-or-accumulator-with-memory
 [[Category:ASM]]
 [[Category:Group One Instructions]]
 [[Category:Inherited from 6502]]