If you are still using the old URL (datacrystal.romhacking.net), please update your bookmarks! The old URL may stop working soon.
The current URL is datacrystal.tcrf.net.
The current URL is datacrystal.tcrf.net.
6502 opcodes
Jump to navigation
Jump to search
The following table contains a list of opcodes for the 6502 processor, used in the NES. (this list is incomplete. For a full list of opcodes used by the 6502, including undocumented and illegal instructions, see http://www.oxyron.de/html/opcodes02.html)
- ABS = Absolute
- ACC = Accumulator
- IMM = Immediate
- IND = Indirect
Mnemonic | Description | Implied / ACC | (IND),X | (IND,Y) | ABS | ABS,X | IMM | ABS,Y | Zero Page | Zero Page,X |
---|---|---|---|---|---|---|---|---|---|---|
ADC | add memory to accumulator with carry | 61 | 71 | 6D | 7D | 69 | 79 | 65 | 75 | |
AND | AND memory with accumulator | 21 | 31 | 2D | 3D | 29 | 39 | 25 | 35 | |
ASL | shift left one bit (memory or accumulator) | 0A | 06 | 16 | ||||||
BCC | branch on carry clear | 90 | ||||||||
BCS | branch on carry set | B0 | ||||||||
BEQ | branch on result zero | F0 | ||||||||
BIT | test bits in memory with accumulator | 2C | 24 | |||||||
BMI | branch on result minus | 30 | ||||||||
BNE | branch on result not zero | D0 | ||||||||
BPL | branch on result plus | 10 | ||||||||
BVC | branch on overflow clear | 50 | ||||||||
BVS | branch on overflow set | 70 | ||||||||
CLC | clear carry flag | 18 | ||||||||
CLD | clear decimal mode | D8 | ||||||||
CLI | clear interrupt disable bit | 58 | ||||||||
CLV | clear overflow flag | B8 | ||||||||
CMP | compare memory and accumulator | C1 | D1 | CD | DD | C9 | D9 | C5 | D5 | |
CPX | compare memory and X register | EC | E0 | E4 | ||||||
CPY | compare memory and Y register | CC | C0 | C4 | ||||||
Mnemonic | Description | Implied / ACC | (IND),X | (IND,Y) | ABS | ABS,X | IMM | ABS,Y | Zero Page | Zero Page,X |
DEC | decrement memory | CE | DE | C6 | D6 | |||||
DEX | decrement X register | CA | ||||||||
DEY | decrement Y register | 88 | ||||||||
EOR | EXCLUSIVE OR memory with accumulator | 41 | 51 | 4D | 5D | 49 | 59 | 45 | 55 | |
INC | increment memory | EE | FE | E6 | F6 | |||||
INX | increment X register | E8 | ||||||||
INY | increment Y register | C8 | ||||||||
JMP | jump to new location | 6C | 4C | |||||||
JSR | jump to new location saving return address | 20 | ||||||||
LDA | load accumulator with memory | A1 | B1 | AD | BD | A9 | B9 | A5 | B5 | |
LDX | load X register with memory | AE | A2 | BE | A6 | B6 | ||||
LDY | load Y register with memory | AC | BC | A0 | A4 | B4 | ||||
LSR | shift right one bit (memory or accumulator) | 4A | 4E | 5E | 46 | |||||
NOP | no operation | EA | ||||||||
ORA | OR memory with accumulator | 01 | 11 | 0D | 1D | 09 | 19 | 05 | 15 | |
PHA | push accumulator on stack | 48 | ||||||||
PHP | push processor status on stack | 08 | ||||||||
PLA | pull accumulator from from stack | 68 | ||||||||
PLP | pull processor status from stack | 28 | ||||||||
Mnemonic | Description | Implied / ACC | (IND),X | (IND,Y) | ABS | ABS,X | IMM | ABS,Y | Zero Page | Zero Page,X |
ROL | rotate one bit left (memory or accumulator) | 2A | 2E | 26 | 36 | |||||
ROR | rotate one bit right (memory or accumulator) | 6A | 6E | 7E | 66 | 76 | ||||
RTI | return from interrupt | 40 | ||||||||
RTS | return from subroutine | 60 | ||||||||
SBC | subtract memory from accumulator with borrow | E1 | F1 | ED | FD | E9 | F9 | E5 | F5 | |
SEC | set carry flag | 38 | ||||||||
SED | set decimal mode | F8 | ||||||||
SEI | set interrupt disable bit | 78 | ||||||||
STA | store accumulator in memory | 81 | 91 | 8D | 9D | 99 | 85 | 95 | ||
STX | store X register in memory | 8E | 86 | 96 | ||||||
STY | store Y register in memory | 8C | 84 | 94 | ||||||
TAX | transfer accumulator to X register | AA | ||||||||
TAY | transfer accumulator to Y register | A8 | ||||||||
TSX | transfer stack pointer to X register | BA | ||||||||
TXA | transfer X register to accumulator | 8A | ||||||||
TXS | transfer X register to stack pointer | 9A | ||||||||
TYA | transfer Y register to accumulator | 98 |