6502 Family CPU Reference

by Michael Steil. [github.com/mist64/c64ref, rev fd22ad3, 2025-03-12]

CPU Undocumented opcodes Separate

Organization

	x0	x1	x2	x3	x4	x5	x6	x7	x8	x9	xA	xB	xC	xD	xE	xF
0x	BRK 71	ORA (a8,X) 62				ORA a8 32	ASL a8 52		PHP 31	ORA #d8 22	ASL A 21			ORA a16 43	ASL a16 63
1x	BPL r8 2-42	ORA (a8),Y 5-62				ORA a8,X 42	ASL a8,X 62		CLC 21	ORA a16,Y 4-53				ORA a16,X 4-53	ASL a16,X 73
2x	JSR a16 63	AND (a8,X) 62			BIT a8 32	AND a8 32	ROL a8 52		PLP 41	AND #d8 22	ROL A 21		BIT a16 43	AND a16 43	ROL a16 63
3x	BMI r8 2-42	AND (a8),Y 5-62				AND a8,X 42	ROL a8,X 62		SEC 21	AND a16,Y 4-53				AND a16,X 4-53	ROL a16,X 73
4x	RTI 61	EOR (a8,X) 62				EOR a8 32	LSR a8 52		PHA 31	EOR #d8 22	LSR A 21		JMP a16 33	EOR a16 43	LSR a16 63
5x	BVC r8 2-42	EOR (a8),Y 5-62				EOR a8,X 42	LSR a8,X 62		CLI 21	EOR a16,Y 4-53				EOR a16,X 4-53	LSR a16,X 73
6x	RTS 61	ADC (a8,X) 62				ADC a8 32	ROR a8 52		PLA 41	ADC #d8 22	ROR A 21		JMP (a16) 53	ADC a16 43	ROR a16 63
7x	BVS r8 2-42	ADC (a8),Y 5-62				ADC a8,X 42	ROR a8,X 62		SEI 21	ADC a16,Y 4-53				ADC a16,X 4-53	ROR a16,X 73
8x		STA (a8,X) 62			STY a8 32	STA a8 32	STX a8 32		DEY 21		TXA 21		STY a16 43	STA a16 43	STX a16 43
9x	BCC r8 2-42	STA (a8),Y 62			STY a8,X 42	STA a8,X 42	STX a8,Y 42		TYA 21	STA a16,Y 53	TXS 21			STA a16,X 53
Ax	LDY #d8 22	LDA (a8,X) 62	LDX #d8 22		LDY a8 32	LDA a8 32	LDX a8 32		TAY 21	LDA #d8 22	TAX 21		LDY a16 43	LDA a16 43	LDX a16 43
Bx	BCS r8 2-42	LDA (a8),Y 5-62			LDY a8,X 42	LDA a8,X 42	LDX a8,Y 42		CLV 21	LDA a16,Y 4-53	TSX 21		LDY a16,X 4-53	LDA a16,X 4-53	LDX a16,Y 4-53
Cx	CPY #d8 22	CMP (a8,X) 62			CPY a8 32	CMP a8 32	DEC a8 52		INY 21	CMP #d8 22	DEX 21		CPY a16 43	CMP a16 43	DEC a16 63
Dx	BNE r8 2-42	CMP (a8),Y 5-62				CMP a8,X 42	DEC a8,X 62		CLD 21	CMP a16,Y 4-53				CMP a16,X 4-53	DEC a16,X 73
Ex	CPX #d8 22	SBC (a8,X) 62			CPX a8 32	SBC a8 32	INC a8 52		INX 21	SBC #d8 22	NOP 21		CPX a16 43	SBC a16 43	INC a16 63
Fx	BEQ r8 2-42	SBC (a8),Y 5-62				SBC a8,X 42	INC a8,X 62		SED 21	SBC a16,Y 4-53				SBC a16,X 4-53	INC a16,X 73

Load/Store

Transfer

Stack

Shift

Logic

Arithmetic

Arithmetic: Inc/Dec

Control Flow

Control Flow: Branch

Flags

KIL

NOP