6502 instructions: Difference between revisions
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== External links == | == External links == | ||
* | * https://www.nesdev.org/obelisk-6502-guide/reference.html - Instruction reference with flag behavior and timing | ||
* http://users.telenet.be/kim1-6502/6502/proman.html - MOS 6502 programming manual | * 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) | * http://nesdev.org/6502_cpu.txt - Includes tick-by-tick breakdowns of instructions (see [[CPU interrupts]] for breakdowns of interrupts) | ||
* [http://visual6502.org/ Visual 6502] can be used to figure out obscure instruction behavior. There's also a [http://www.qmtpro.com/~nes/chipimages/visual2a03/ 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 [[Visual_circuit_tutorial|a tutorial on reading the circuit diagrams]] available, aimed at beginners. | * [http://visual6502.org/ Visual 6502] can be used to figure out obscure instruction behavior. There's also a [http://www.qmtpro.com/~nes/chipimages/visual2a03/ 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 [[Visual_circuit_tutorial|a tutorial on reading the circuit diagrams]] available, aimed at beginners. | ||
Revision as of 17:07, 28 January 2022
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
- https://www.nesdev.org/obelisk-6502-guide/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.
