6502/6502-opcodes
1
0
Fork 0
mirror of https://github.com/mcanlas/6502-opcodes.git synced 2025-03-13 13:30:43 +00:00
Code Issues Projects Releases Wiki Activity

document

Browse Source
This commit is contained in:
Mark Canlas 2020-08-11 23:04:23 -04:00
parent ffac8fa333
commit e432132328
1 changed files with 14 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
README.md
View File

@ -1 +1,14 @@
# 6502-opcodes
# 6502-opcodes
## Addressing modes
* Immediate: a value literal
* ZeroPage: argument is an 8-bit address to the zero page
* ZeroPageX: argument is an 8-bit address to the zero page, incremented by X without carry
* ZeroPageY: argument is an 8-bit address to the zero page, incremented by Y without carry
* Absolute: argument is an 16-bit address
* AbsoluteX: argument is an 16-bit address, incremented by X with carry
* AbsoluteY: argument is an 16-bit address, incremented by Y with carry
* Indirect: argument an address (A); the effective value is an address (B) stored at that address (A); used only by Jump
* IndirectX: argument is an 8-bit address; find a value at this address incremented by the value X
* IndirectY: argument is an 8-bit address; find a value at this address; increment the value by Y