Geody Labs


MOS 6502 6510 65xx CPU processor opcodes

from the C=Hacking e-zine issue #1 (December 1991)
compiled by Craig Taylor

6502 Opcodes and Quasi-Opcodes. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The following table lists all of the available opcodes on the 65xx line of micro-processors (such as the 6510 on the C=64 and the 8502 on the C=128) ----------------------------------------------------------------------------- Std Mnemonic Hex Value Description Addressing Mode Bytes/Time * BRK $00 Stack <- PC, PC <- ($fffe) (Immediate) 1/7 * ORA $01 A <- (A) V M (Ind,X) 6/2 JAM $02 [locks up machine] (Implied) 1/- SLO $03 M <- (M >> 1) + A + C (Ind,X) 2/8 NOP $04 [no operation] (Z-Page) 2/3 * ORA $05 A <- (A) V M (Z-Page) 2/3 * ASL $06 C <- A7, A <- (A) << 1 (Z-Page) 2/5 SLO $07 M <- (M >> 1) + A + C (Z-Page) 2/5 * PHP $08 Stack <- (P) (Implied) 1/3 * ORA $09 A <- (A) V M (Immediate) 2/2 * ASL $0A C <- A7, A <- (A) << 1 (Accumalator) 1/2 ANC $0B A <- A /\ M, C=~A7 (Immediate) 1/2 NOP $0C [no operation] (Absolute) 3/4 * ORA $0D A <- (A) V M (Absolute) 3/4 * ASL $0E C <- A7, A <- (A) << 1 (Absolute) 3/6 SLO $0F M <- (M >> 1) + A + C (Absolute) 3/6 * BPL $10 if N=0, PC = PC + offset (Relative) 2/2'2 * ORA $11 A <- (A) V M ((Ind),Y) 2/5'1 JAM $12 [locks up machine] (Implied) 1/- SLO $13 M <- (M >. 1) + A + C ((Ind),Y) 2/8'5 NOP $14 [no operation] (Z-Page,X) 2/4 * ORA $15 A <- (A) V M (Z-Page,X) 2/4 * ASL $16 C <- A7, A <- (A) << 1 (Z-Page,X) 2/6 SLO $17 M <- (M >> 1) + A + C (Z-Page,X) 2/6 * CLC $18 C <- 0 (Implied) 1/2 * ORA $19 A <- (A) V M (Absolute,Y) 3/4'1 NOP $1A [no operation] (Implied) 1/2 SLO $1B M <- (M >> 1) + A + C (Absolute,Y) 3/7 NOP $1C [no operation] (Absolute,X) 2/4'1 * ORA $1D A <- (A) V M (Absolute,X) 3/4'1 * ASL $1E C <- A7, A <- (A) << 1 (Absolute,X) 3/7 SLO $1F M <- (M >> 1) + A + C (Absolute,X) 3/7 * JSR $20 Stack <- PC, PC <- Address (Absolute) 3/6 * AND $21 A <- (A) /\ M (Ind,X) 2/6 JAM $22 [locks up machine] (Implied) 1/- RLA $23 M <- (M << 1) /\ (A) (Ind,X) 2/8 * BIT $24 Z <- ~(A /\ M) N<-M7 V<-M6 (Z-Page) 2/3 * AND $25 A <- (A) /\ M (Z-Page) 2/3 * ROL $26 C <- A7 & A <- A << 1 + C (Z-Page) 2/5 RLA $27 M <- (M << 1) /\ (A) (Z-Page) 2/5'5 * PLP $28 A <- (Stack) (Implied) 1/4 * AND $29 A <- (A) /\ M (Immediate) 2/2 * ROL $2A C <- A7 & A <- A << 1 + C (Accumalator) 1/2 ANC $2B A <- A /\ M, C <- ~A7 (Immediate9 1/2 * BIT $2C Z <- ~(A /\ M) N<-M7 V<-M6 (Absolute) 3/4 * AND $2D A <- (A) /\ M (Absolute) 3/4 * ROL $2E C <- A7 & A <- A << 1 + C (Absolute) 3/6 RLA $2F M <- (M << 1) /\ (A) (Absolute) 3/6'5 * BMI $30 if N=1, PC = PC + offset (Relative) 2/2'2 * AND $31 A <- (A) /\ M ((Ind),Y) 2/5'1 JAM $32 [locks up machine] (Implied) 1/- RLA $33 M <- (M << 1) /\ (A) ((Ind),Y) 2/8'5 NOP $34 [no operation] (Z-Page,X) 2/4 * AND $35 A <- (A) /\ M (Z-Page,X) 2/4 * ROL $36 C <- A7 & A <- A << 1 + C (Z-Page,X) 2/6 RLA $37 M <- (M << 1) /\ (A) (Z-Page,X) 2/6'5 * SEC $38 C <- 1 (Implied) 1/2 * AND $39 A <- (A) /\ M (Absolute,Y) 3/4'1 NOP $3A [no operation] (Implied) 1/2 RLA $3B M <- (M << 1) /\ (A) (Absolute,Y) 3/7'5 NOP $3C [no operation] (Absolute,X) 3/4'1 * AND $3D A <- (A) /\ M (Absolute,X) 3/4'1 * ROL $3E C <- A7 & A <- A << 1 + C (Absolute,X) 3/7 RLA $3F M <- (M << 1) /\ (A) (Absolute,X) 3/7'5 * RTI $40 P <- (Stack), PC <-(Stack) (Implied) 1/6 * EOR $41 A <- (A) \-/ M (Ind,X) 2/6 JAM $42 [locks up machine] (Implied) 1/- SRE $43 M <- (M >> 1) \-/ A (Ind,X) 2/8 NOP $44 [no operation] (Z-Page) 2/3 * EOR $45 A <- (A) \-/ M (Z-Page) 2/3 * LSR $46 C <- A0, A <- (A) >> 1 (Absolute,X) 3/7 SRE $47 M <- (M >> 1) \-/ A (Z-Page) 2/5 * PHA $48 Stack <- (A) (Implied) 1/3 * EOR $49 A <- (A) \-/ M (Immediate) 2/2 * LSR $4A C <- A0, A <- (A) >> 1 (Accumalator) 1/2 ASR $4B A <- [(A /\ M) >> 1] (Immediate) 1/2 * JMP $4C PC <- Address (Absolute) 3/3 * EOR $4D A <- (A) \-/ M (Absolute) 3/4 * LSR $4E C <- A0, A <- (A) >> 1 (Absolute) 3/6 SRE $4F M <- (M >> 1) \-/ A (Absolute) 3/6 * BVC $50 if V=0, PC = PC + offset (Relative) 2/2'2 * EOR $51 A <- (A) \-/ M ((Ind),Y) 2/5'1 JAM $52 [locks up machine] (Implied) 1/- SRE $53 M <- (M >> 1) \-/ A ((Ind),Y) 2/8 NOP $54 [no operation] (Z-Page,X) 2/4 * EOR $55 A <- (A) \-/ M (Z-Page,X) 2/4 * LSR $56 C <- A0, A <- (A) >> 1 (Z-Page,X) 2/6 SRE $57 M <- (M >> 1) \-/ A (Z-Page,X) 2/6 * CLI $58 I <- 0 (Implied) 1/2 * EOR $59 A <- (A) \-/ M (Absolute,Y) 3/4'1 NOP $5A [no operation] (Implied) 1/2 SRE $5B M <- (M >> 1) \-/ A (Absolute,Y) 3/7 NOP $5C [no operation] (Absolute,X) 3/4'1 * EOR $5D A <- (A) \-/ M (Absolute,X) 3/4'1 SRE $5F M <- (M >> 1) \-/ A (Absolute,X) 3/7 * RTS $60 PC <- (Stack) (Implied) 1/6 * ADC $61 A <- (A) + M + C (Ind,X) 2/6 JAM $62 [locks up machine] (Implied) 1/- RRA $63 M <- (M >> 1) + (A) + C (Ind,X) 2/8'5 NOP $64 [no operation] (Z-Page) 2/3 * ADC $65 A <- (A) + M + C (Z-Page) 2/3 * ROR $66 C<-A0 & A<- (A7=C + A>>1) (Z-Page) 2/5 RRA $67 M <- (M >> 1) + (A) + C (Z-Page) 2/5'5 * PLA $68 A <- (Stack) (Implied) 1/4 * ADC $69 A <- (A) + M + C (Immediate) 2/2 * ROR $6A C<-A0 & A<- (A7=C + A>>1) (Accumalator) 1/2 ARR $6B A <- [(A /\ M) >> 1] (Immediate) 1/2'5 * JMP $6C PC <- Address (Indirect) 3/5 * ADC $6D A <- (A) + M + C (Absolute) 3/4 * ROR $6E C<-A0 & A<- (A7=C + A>>1) (Absolute) 3/6 RRA $6F M <- (M >> 1) + (A) + C (Absolute) 3/6'5 * BVS $70 if V=1, PC = PC + offset (Relative) 2/2'2 * ADC $71 A <- (A) + M + C ((Ind),Y) 2/5'1 JAM $72 [locks up machine] (Implied) 1/- RRA $73 M <- (M >> 1) + (A) + C ((Ind),Y) 2/8'5 NOP $74 [no operation] (Z-Page,X) 2/4 * ADC $75 A <- (A) + M + C (Z-Page,X) 2/4 * ROR $76 C<-A0 & A<- (A7=C + A>>1) (Z-Page,X) 2/6 RRA $77 M <- (M >> 1) + (A) + C (Z-Page,X) 2/6'5 * SEI $78 I <- 1 (Implied) 1/2 * ADC $79 A <- (A) + M + C (Absolute,Y) 3/4'1 NOP $7A [no operation] (Implied) 1/2 RRA $7B M <- (M >> 1) + (A) + C (Absolute,Y) 3/7'5 NOP $7C [no operation] (Absolute,X) 3/4'1 * ADC $7D A <- (A) + M + C (Absolute,X) 3/4'1 * ROR $7E C<-A0 & A<- (A7=C + A>>1) (Absolute,X) 3/7 RRA $7F M <- (M >> 1) + (A) + C (Absolute,X) 3/7'5 NOP $80 [no operation] (Immediate) 2/2 * STA $81 M <- (A) (Ind,X) 2/6 NOP $82 [no operation] (Immediate) 2/2 SAX $83 M <- (A) /\ (X) (Ind,X) 2/6 * STY $84 M <- (Y) (Z-Page) 2/3 * STA $85 M <- (A) (Z-Page) 2/3 * STX $86 M <- (X) (Z-Page) 2/3 SAX $87 M <- (A) /\ (X) (Z-Page) 2/3 * DEY $88 Y <- (Y) - 1 (Implied) 1/2 NOP $89 [no operation] (Immediate) 2/2 * TXA $8A A <- (X) (Implied) 1/2 ANE $8B M <-[(A)\/$EE] /\ (X)/\(M) (Immediate) 2/2^4 * STY $8C M <- (Y) (Absolute) 3/4 * STA $8D M <- (A) (Absolute) 3/4 * STX $8E M <- (X) (Absolute) 3/4 SAX $8F M <- (A) /\ (X) (Absolute) 3/4 * BCC $90 if C=0, PC = PC + offset (Relative) 2/2'2 * STA $91 M <- (A) ((Ind),Y) 2/6 JAM $92 [locks up machine] (Implied) 1/- SHA $93 M <- (A) /\ (X) /\ (PCH+1) (Absolute,X) 3/6'3 * STY $94 M <- (Y) (Z-Page,X) 2/4 * STA $95 M <- (A) (Z-Page,X) 2/4 SAX $97 M <- (A) /\ (X) (Z-Page,Y) 2/4 * STX $96 M <- (X) (Z-Page,Y) 2/4 * TYA $98 A <- (Y) (Implied) 1/2 * STA $99 M <- (A) (Absolute,Y) 3/5 * TXS $9A S <- (X) (Implied) 1/2 SHS $9B X <- (A) /\ (X), S <- (X) (Absolute,Y) 3/5 M <- (X) /\ (PCH+1) SHY $9C M <- (Y) /\ (PCH+1) (Absolute,Y) 3/5'3 * STA $9D M <- (A) (Absolute,X) 3/5 SHX $9E M <- (X) /\ (PCH+1) (Absolute,X) 3/5'3 SHA $9F M <- (A) /\ (X) /\ (PCH+1) (Absolute,Y) 3/5'3 * LDY $A0 Y <- M (Immediate) 2/2 * LDA $A1 A <- M (Ind,X) 2/6 * LDX $A2 X <- M (Immediate) 2/2 LAX $A3 A <- M, X <- M (Ind,X) 2/6 * LDY $A4 Y <- M (Z-Page) 2/3 * LDA $A5 A <- M (Z-Page) 2/3 * LDX $A6 X <- M (Z-Page) 2/3 LAX $A7 A <- M, X <- M (Z-Page) 2/3 * TAY $A8 Y <- (A) (Implied) 1/2 * LDA $A9 A <- M (Immediate) 2/2 * TAX $AA X <- (A) (Implied) 1/2 LXA $AB X04 <- (X04) /\ M04 (Immediate) 1/2 A04 <- (A04) /\ M04 * LDY $AC Y <- M (Absolute) 3/4 * LDA $AD A <- M (Absolute) 3/4 * LDX $AE X <- M (Absolute) 3/4 LAX $AF A <- M, X <- M (Absolute) 3/4 * BCS $B0 if C=1, PC = PC + offset (Relative) 2/2'2 * LDA $B1 A <- M ((Ind),Y) 2/5'1 JAM $B2 [locks up machine] (Implied) 1/- LAX $B3 A <- M, X <- M ((Ind),Y) 2/5'1 * LDY $B4 Y <- M (Z-Page,X) 2/4 * LDA $B5 A <- M (Z-Page,X) 2/4 * LDX $B6 X <- M (Z-Page,Y) 2/4 LAX $B7 A <- M, X <- M (Z-Page,Y) 2/4 * CLV $B8 V <- 0 (Implied) 1/2 * LDA $B9 A <- M (Absolute,Y) 3/4'1 * TSX $BA X <- (S) (Implied) 1/2 LAE $BB X,S,A <- (S /\ M) (Absolute,Y) 3/4'1 * LDY $BC Y <- M (Absolute,X) 3/4'1 * LDA $BD A <- M (Absolute,X) 3/4'1 * LDX $BE X <- M (Absolute,Y) 3/4'1 LAX $BF A <- M, X <- M (Absolute,Y) 3/4'1 * CPY $C0 (Y - M) -> NZC (Immediate) 2/2 * CMP $C1 (A - M) -> NZC (Ind,X) 2/6 NOP $C2 [no operation] (Immediate) 2/2 DCP $C3 M <- (M)-1, (A-M) -> NZC (Ind,X) 2/8 * CPY $C4 (Y - M) -> NZC (Z-Page) 2/3 * CMP $C5 (A - M) -> NZC (Z-Page) 2/3 * DEC $C6 M <- (M) - 1 (Z-Page) 2/5 DCP $C7 M <- (M)-1, (A-M) -> NZC (Z-Page) 2/5 * INY $C8 Y <- (Y) + 1 (Implied) 1/2 * CMP $C9 (A - M) -> NZC (Immediate) 2/2 * DEX $CA X <- (X) - 1 (Implied) 1/2 SBX $CB X <- (X)/\(A) - M (Immediate) 2/2 * CPY $CC (Y - M) -> NZC (Absolute) 3/4 * CMP $CD (A - M) -> NZC (Absolute) 3/4 * DEC $CE M <- (M) - 1 (Absolute) 3/6 DCP $CF M <- (M)-1, (A-M) -> NZC (Absolute) 3/6 * BNE $D0 if Z=0, PC = PC + offset (Relative) 2/2'2 * CMP $D1 (A - M) -> NZC ((Ind),Y) 2/5'1 JAM $D2 [locks up machine] (Implied) 1/- DCP $D3 M <- (M)-1, (A-M) -> NZC ((Ind),Y) 2/8 NOP $D4 [no operation] (Z-Page,X) 2/4 * CMP $D5 (A - M) -> NZC (Z-Page,X) 2/4 * DEC $D6 M <- (M) - 1 (Z-Page,X) 2/6 DCP $D7 M <- (M)-1, (A-M) -> NZC (Z-Page,X) 2/6 * CLD $D8 D <- 0 (Implied) 1/2 * CMP $D9 (A - M) -> NZC (Absolute,Y) 3/4'1 NOP $DA [no operation] (Implied) 1/2 DCP $DB M <- (M)-1, (A-M) -> NZC (Absolute,Y) 3/7 NOP $DC [no operation] (Absolute,X) 3/4'1 * CMP $DD (A - M) -> NZC (Absolute,X) 3/4'1 * DEC $DE M <- (M) - 1 (Absolute,X) 3/7 DCP $DF M <- (M)-1, (A-M) -> NZC (Absolute,X) 3/7 * CPX $E0 (X - M) -> NZC (Immediate) 2/2 * SBC $E1 A <- (A) - M - ~C (Ind,X) 2/6 NOP $E2 [no operation] (Immediate) 2/2 ISB $E3 M <- (M) - 1,A <- (A)-M-~C (Ind,X) 3/8'1 * CPX $E4 (X - M) -> NZC (Z-Page) 2/3 * SBC $E5 A <- (A) - M - ~C (Z-Page) 2/3 * INC $E6 M <- (M) + 1 (Z-Page) 2/5 ISB $E7 M <- (M) - 1,A <- (A)-M-~C (Z-Page) 2/5 * INX $E8 X <- (X) +1 (Implied) 1/2 * SBC $E9 A <- (A) - M - ~C (Immediate) 2/2 * NOP $EA [no operation] (Implied) 1/2 SBC $EB A <- (A) - M - ~C (Immediate) 1/2 * SBC $ED A <- (A) - M - ~C (Absolute) 3/4 * CPX $EC (X - M) -> NZC (Absolute) 3/4 * INC $EE M <- (M) + 1 (Absolute) 3/6 ISB $EF M <- (M) - 1,A <- (A)-M-~C (Absolute) 3/6 * BEQ $F0 if Z=1, PC = PC + offset (Relative) 2/2'2 * SBC $F1 A <- (A) - M - ~C ((Ind),Y) 2/5'1 JAM $F2 [locks up machine] (Implied) 1/- ISB $F3 M <- (M) - 1,A <- (A)-M-~C ((Ind),Y) 2/8 NOP $F4 [no operation] (Z-Page,X) 2/4 * SBC $F5 A <- (A) - M - ~C (Z-Page,X) 2/4 * INC $F6 M <- (M) + 1 (Z-Page,X) 2/6 ISB $F7 M <- (M) - 1,A <- (A)-M-~C (Z-Page,X) 2/6 * SED $F8 D <- 1 (Implied) 1/2 * SBC $F9 A <- (A) - M - ~C (Absolute,Y) 3/4'1 NOP $FA [no operation] (Implied) 1/2 ISB $FB M <- (M) - 1,A <- (A)-M-~C (Absolute,Y) 3/7 NOP $FC [no operation] (Absolute,X) 3/4'1 * SBC $FD A <- (A) - M - ~C (Absolute,X) 3/4'1 * INC $FE M <- (M) + 1 (Absolute,X) 3/7 ISB $FF M <- (M) - 1,A <- (A)-M-~C (Absolute,X) 3/7 '1 - Add one if address crosses a page boundry. '2 - Add 1 if branch succeeds, or 2 if into another page. '3 - If page boundry crossed then PCH+1 is just PCH '4 - Sources disputed on exact operation, or sometimes does not work. '5 - Full eight bit rotation (with carry) Sources: Programming the 6502, Rodney Zaks, (c) 1983 Sybex Paul Ojala, Post to Comp.Sys.Cbm (po87553@cs.tut.fi / albert@cc.tut.fi) D John Mckenna, Post to Comp.Sys.Cbm (gudjm@uniwa.uwa.oz.au) Compiled by Craig Taylor (duck@pembvax1.pembroke.edu)




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