6502 instructions: Difference between revisions
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* [[6502 assembly optimisations]] | * [[6502 assembly optimisations]] | ||
* [[Delay code]], and [[Fixed cycle delay]]: how to create a delay of a precise number of CPU cycles with smallest number of code bytes | * [[Delay code]], and [[Fixed cycle delay]]: how to create a delay of a precise number of CPU cycles with smallest number of code bytes | ||
* [[6502 cycle times]] | |||
== External links == | == External links == | ||
Revision as of 05:16, 7 November 2021
Below are some references for the 6502 instruction set:
- CPU unofficial opcodes, including a full opcode matrix of all official and unofficial opcodes
- Programming with unofficial opcodes
- 6502 assembly optimisations
- Delay code, and Fixed cycle delay: how to create a delay of a precise number of CPU cycles with smallest number of code bytes
- 6502 cycle times
External links
- http://obelisk.me.uk/6502/reference.html - Instruction reference with flag behavior and timing
- http://users.telenet.be/kim1-6502/6502/proman.html - MOS 6502 programming manual
- http://nesdev.org/6502_cpu.txt - Includes tick-by-tick breakdowns of instructions (see CPU interrupts for breakdowns of interrupts)
- Visual 6502 can be used to figure out obscure instruction behavior. There's also a 2A03 version available (please avoid shift-reloading it as it is hosted on a limited uplink; normal reloading should work fine and should catch any updates to the data files). There is also a tutorial on reading the circuit diagrams available, aimed at beginners.
