diff --git a/src/65c02isa.csv b/src/65c02isa.csv
index 70c4b08..c229a4a 100644
--- a/src/65c02isa.csv
+++ b/src/65c02isa.csv
@@ -1,257 +1,257 @@
-opcode_id,mnemonic,addressing,size,emulation
-OP_BRK,"brk",IMPLIED,1,NULL
-OP_ORA_IZPX,"ora",IZPX,2,emul_ora
-OP_NOPI_3,"nop",IMMEDIATE,2,NULL
-OP_NOPI_4,"nop",IMPLIED,1,NULL
-OP_TSB_ZP,"tsb",ZP,2,NULL
-OP_ORA_ZP,"ora",ZP,2,emul_ora
-OP_ASL_ZP,"asl",ZP,2,emul_asl
-OP_RMB0_ZP,"rmb0",ZP,2,emul_rmb0
-OP_PHP,"php",IMPLIED,1,emul_php
-OP_ORA_IMM,"ora",IMMEDIATE,2,emul_ora
-OP_ASL,"asl",ACCUMULATOR,1,emul_asl
-OP_NOPI_C,"nop",IMPLIED,1,NULL
-OP_TSB_ABS,"tsb",ABSOLUTE,3,NULL
-OP_ORA_ABS,"ora",ABSOLUTE,3,emul_ora
-OP_ASL_ABS,"asl",ABSOLUTE,3,emul_asl
-OP_BBR0_REL,"bbr0",ZPR,2,NULL
-OP_BPL_REL,"bpl",RELATIVE,2,NULL
-OP_ORA_IZPY,"ora",IZPY,2,emul_ora
-OP_ORA_IZP,"ora",IZP,2,emul_ora
-OP_NOPI_14,"nop",IMPLIED,1,NULL
-OP_TRB_ZP,"trb",ZP,2,NULL
-OP_ORA_ZPX,"ora",ZPX,2,emul_ora
-OP_ASL_ZPX,"asl",ZPX,2,emul_asl
-OP_RMB1_ZP,"rmb1",ZP,1,emul_rmb1
-OP_CLC,"clc",IMPLIED,1,emul_clc
-OP_ORA_ABSY,"ora",ABSOLUTEY,3,emul_ora
-OP_INC,"inc",ACCUMULATOR,1,emul_inc
-OP_NOPI_1C,"nop",IMPLIED,1,NULL
-OP_TRB_ABS,"trb",ABSOLUTE,3,NULL
-OP_ORA_ABSX,"ora",ABSOLUTEX,3,emul_ora
-OP_ASL_ABSX,"asl",ABSOLUTEX,3,emul_asl
-OP_BBR1_REL,"bbr1",ZPR,2,NULL
-OP_JSR,"jsr",ABSOLUTE,3,NULL
-OP_AND_IZPX,"and",IZPX,2,emul_and
-OP_NOPI_23,"nop",IMMEDIATE,2,NULL
-OP_NOPI_24,"nop",IMPLIED,1,NULL
-OP_BIT_ZP,"bit",ZP,2,emul_bit
-OP_AND_ZP,"and",ZP,2,emul_and
-OP_ROL_ZP,"rol",ZP,2,emul_rol
-OP_RMB2_ZP,"rmb2",ZP,2,emul_rmb2
-OP_PLP,"plp",IMPLIED,1,emul_plp
-OP_AND_IMM,"and",IMMEDIATE,2,emul_and
-OP_ROL,"rol",ACCUMULATOR,1,emul_rol
-OP_NOPI_2C,"nop",IMPLIED,1,NULL
-OP_BIT_ABS,"bit",ABSOLUTE,3,emul_bit
-OP_AND_ABS,"and",ABSOLUTE,3,emul_and
-OP_ROL_ABS,"rol",ABSOLUTE,3,emul_rol
-OP_BBR2_REL,"bbr2",ZPR,2,NULL
-OP_BMI_REL,"bmi",RELATIVE,2,NULL
-OP_AND_IZPY,"and",IZPY,2,emul_and
-OP_AND_IZP,"and",IZP,2,emul_and
-OP_NOPI_34,"nop",IMPLIED,1,NULL
-OP_BIT_ZPX,"bit",ZPX,2,emul_bit
-OP_AND_ZPX,"and",ZPX,2,emul_and
-OP_ROL_ZPX,"rol",ZPX,2,emul_rol
-OP_RMB3_ZP,"rmb3",ZP,2,emul_rmb3
-OP_SEC,"sec",IMPLIED,1,emul_sec
-OP_AND_ABSY,"and",ABSOLUTEY,3,emul_and
-OP_DEC,"dec",ACCUMULATOR,1,emul_dec
-OP_NOPI_3C,"nop",IMPLIED,1,NULL
-OP_BIT_ABSX,"bit",ABSOLUTEX,3,emul_bit
-OP_AND_ABSX,"and",ABSOLUTEX,3,emul_and
-OP_ROL_ABSX,"rol",ABSOLUTEX,3,emul_rol
-OP_BBR3_REL,"bbr3",ZPR,2,NULL
-OP_RTI,"rti",IMPLIED,1,NULL
-OP_EOR_IZPX,"eor",IZPX,2,emul_eor
-OP_NOPI_43,"nop",IMMEDIATE,2,NULL
-OP_NOPI_44,"nop",IMPLIED,1,NULL
-OP_NOPI_45,"nop",ZP,2,NULL
-OP_EOR_ZP,"eor",ZP,2,emul_eor
-OP_LSR_ZP,"lsr",ZP,2,emul_lsr
-OP_RMB4_ZP,"rmb4",ZP,2,emul_rmb4
-OP_PHA,"pha",IMPLIED,1,emul_pha
-OP_EOR_IMM,"eor",IMMEDIATE,2,emul_eor
-OP_LSR,"lsr",ACCUMULATOR,1,emul_lsr
-OP_NOPI_4C,"nop",IMPLIED,1,NULL
-OP_JMP_ABS,"jmp",ABSOLUTE,3,NULL
-OP_EOR_ABS,"eor",ABSOLUTE,3,emul_eor
-OP_LSR_ABS,"lsr",ABSOLUTE,3,emul_lsr
-OP_BBR4_REL,"bbr4",ZPR,2,NULL
-OP_BVC_REL,"bvc",RELATIVE,2,NULL
-OP_EOR_IZPY,"eor",IZPY,2,emul_eor
-OP_EOR_IZP,"eor",IZP,2,emul_eor
-OP_NOPI_54,"nop",IMPLIED,1,NULL
-OP_NOPI_55,"nop",ZPX,2,NULL
-OP_EOR_ZPX,"eor",ZPX,2,emul_eor
-OP_LSR_ZPX,"lsr",ZPX,2,emul_lsr
-OP_RMB5_ZP,"rmb5",ZP,2,emul_rmb5
-OP_CLI,"cli",IMPLIED,1,NULL
-OP_EOR_ABSY,"eor",ABSOLUTEY,3,emul_eor
-OP_PHY,"phy",IMPLIED,1,emul_phy
-OP_NOPI_5C,"nop",IMPLIED,1,NULL
-OP_NOPI_5D,"nop",ABSOLUTE,3,NULL
-OP_EOR_ABSX,"eor",ABSOLUTEX,3,emul_eor
-OP_LSR_ABSX,"lsr",ABSOLUTEX,3,emul_lsr
-OP_BBR5_REL,"bbr5",ZPR,2,NULL
-OP_RTS,"rts",IMPLIED,1,NULL
-OP_ADC_IZPX,"adc",IZPX,2,NULL
-OP_NOPI_63,"nop",IMMEDIATE,2,NULL
-OP_NOPI_64,"nop",IMPLIED,1,NULL
-OP_STZ_ZP,"stz",ZP,2,emul_stz
-OP_ADC_ZP,"adc",ZP,2,NULL
-OP_ROR_ZP,"ror",ZP,2,emul_ror
-OP_RMB6_ZP,"rmb6",ZP,2,emul_rmb6
-OP_PLA,"pla",IMPLIED,1,emul_pla
-OP_ADC_IMM,"adc",IMMEDIATE,2,NULL
-OP_ROR,"ror",ACCUMULATOR,1,emul_ror
-OP_NOPI_6C,"nop",IMPLIED,1,NULL
-OP_JMP_IABS,"jmp",IABSOLUTE,3,NULL
-OP_ADC_ABS,"adc",ABSOLUTE,3,NULL
-OP_ROR_ABS,"ror",ABSOLUTE,3,emul_ror
-OP_BBR6_REL,"bbr6",ZPR,2,NULL
-OP_BVS_REL,"bvs",RELATIVE,2,NULL
-OP_ADC_IZPY,"adc",IZPY,2,NULL
-OP_ADC_IZP,"adc",IZP,2,NULL
-OP_NOPI_74,"nop",IMPLIED,1,NULL
-OP_STZ_ZPX,"stz",ZPX,2,emul_stz
-OP_ADC_ZPX,"adc",ZPX,2,NULL
-OP_ROR_ZPX,"ror",ZPX,2,emul_ror
-OP_RMB7_ZP,"rmb7",ZP,2,emul_rmb7
-OP_SEI,"sei",IMPLIED,1,NULL
-OP_ADC_ABSY,"adc",ABSOLUTEY,3,NULL
-OP_PLY,"ply",IMPLIED,1,emul_ply
-OP_NOPI_7C,"nop",IMPLIED,1,NULL
-OP_JMP_IABSX,"jmp",IABSOLUTEX,3,NULL
-OP_ADC_ABSX,"adc",ABSOLUTEX,3,NULL
-OP_ROR_ABSX,"ror",ABSOLUTEX,3,emul_ror
-OP_BBR7_REL,"bbr7",ZPR,2,NULL
-OP_BRA_REL,"bra",RELATIVE,2,NULL
-OP_STA_IZPX,"sta",IZPX,2,emul_sta
-OP_NOPI_83,"nop",IMMEDIATE,2,NULL
-OP_NOPI_84,"nop",IMPLIED,1,NULL
-OP_STY_ZP,"sty",ZP,2,emul_sty
-OP_STA_ZP,"sta",ZP,2,emul_sta
-OP_STX_ZP,"stx",ZP,2,emul_stx
-OP_SMB0_ZP,"smb0",ZP,2,NULL
-OP_DEY,"dey",IMPLIED,1,emul_dey
-OP_BIT_IMM,"bit",IMMEDIATE,2,emul_bit
-OP_TXA,"txa",IMPLIED,1,emul_txa
-OP_NOPI_8C,"nop",IMPLIED,1,NULL
-OP_STY_ABS,"sty",ABSOLUTE,3,emul_sty
-OP_STA_ABS,"sta",ABSOLUTE,3,emul_sta
-OP_STX_ABS,"stx",ABSOLUTE,3,emul_stx
-OP_BBS0_REL,"bbs0",ZPR,2,NULL
-OP_BCC_REL,"bcc",RELATIVE,2,NULL
-OP_STA_IZPY,"sta",IZPY,2,emul_sta
-OP_STA_IZP,"sta",IZP,2,emul_sta
-OP_NOPI_94,"nop",IMPLIED,1,NULL
-OP_STY_ZPX,"sty",ZPX,2,emul_sty
-OP_STA_ZPX,"sta",ZPX,2,emul_sta
-OP_STX_ZPY,"stx",ZPY,2,emul_stx
-OP_SMB1_ZP,"smb1",ZP,2,NULL
-OP_TYA,"tya",IMPLIED,1,emul_tya
-OP_STA_ABSY,"sta",ABSOLUTEY,3,emul_sta
-OP_TXS,"txs",IMPLIED,1,emul_txs
-OP_NOPI_9C,"nop",IMPLIED,1,NULL
-OP_STZ_ABS,"stz",ABSOLUTE,3,emul_stz
-OP_STA_ABSX,"sta",ABSOLUTEX,3,emul_sta
-OP_STZ_ABSX,"stz",ABSOLUTEX,3,emul_stz
-OP_BBS1_REL,"bbs1",ZPR,2,NULL
-OP_LDY_IMM,"ldy",IMMEDIATE,2,emul_ldy
-OP_LDA_IZPX,"lda",IZPX,2,emul_lda
-OP_LDX_IMM,"ldx",IMMEDIATE,2,emul_ldx
-OP_NOPI_A4,"nop",IMPLIED,1,NULL
-OP_LDY_ZP,"ldy",ZP,2,emul_ldy
-OP_LDA_ZP,"lda",ZP,2,emul_lda
-OP_LDX_ZP,"ldx",ZP,2,emul_ldx
-OP_SMB2_ZP,"smb2",ZP,2,NULL
-OP_TAY,"tay",IMPLIED,1,emul_tay
-OP_LDA_IMM,"lda",IMMEDIATE,2,emul_lda
-OP_TAX,"tax",IMPLIED,1,emul_tax
-OP_NOPI_AC,"nop",IMPLIED,1,NULL
-OP_LDY_ABS,"ldy",ABSOLUTE,3,emul_ldy
-OP_LDA_ABS,"lda",ABSOLUTE,3,emul_lda
-OP_LDX_ABS,"ldx",ABSOLUTE,3,emul_ldx
-OP_BBS2_REL,"bbs2",ZPR,2,NULL
-OP_BCS_REL,"bcs",RELATIVE,2,NULL
-OP_LDA_IZPY,"lda",IZPY,2,emul_lda
-OP_LDA_IZP,"lda",IZP,2,emul_lda
-OP_NOPI_B4,"nop",IMPLIED,1,NULL
-OP_LDY_ZPX,"ldy",ZPX,2,emul_ldy
-OP_LDA_ZPX,"lda",ZPX,2,emul_lda
-OP_LDX_ZPY,"ldx",ZPY,1,emul_ldx
-OP_SMB3_ZP,"smb3",ZP,2,NULL
-OP_CLV,"clv",IMPLIED,1,NULL
-OP_LDA_ABSY,"lda",ABSOLUTEY,3,emul_lda
-OP_TSX,"tsx",IMPLIED,1,emul_tsx
-OP_NOPI_BC,"nop",IMPLIED,1,NULL
-OP_LDY_ABSX,"ldy",ABSOLUTEX,3,emul_ldy
-OP_LDA_ABSX,"lda",ABSOLUTEX,3,emul_lda
-OP_LDX_ABSY,"ldx",ABSOLUTEY,3,emul_ldx
-OP_BBS3_REL,"bbs3",ZPR,2,NULL
-OP_CPY_IMM,"cpy",IMMEDIATE,2,NULL
-OP_CMP_IZPX,"cmp",IZPX,2,NULL
-OP_NOPI_C3,"nop",IMMEDIATE,2,NULL
-OP_NOPI_C4,"nop",IMPLIED,1,NULL
-OP_CPY_ZP,"cpy",ZP,2,NULL
-OP_CMP_ZP,"cmp",ZP,2,NULL
-OP_DEC_ZP,"dec",ZP,2,emul_dec
-OP_SMB4_ZP,"smb4",ZP,2,NULL
-OP_INY,"iny",IMPLIED,1,emul_iny
-OP_CMP_IMM,"cmp",IMMEDIATE,2,NULL
-OP_DEX,"dex",IMPLIED,1,emul_dex
-OP_WAI,"wai",IMPLIED,1,NULL
-OP_CPY_ABS,"cpy",ABSOLUTE,3,NULL
-OP_CMP_ABS,"cmp",ABSOLUTE,3,NULL
-OP_DEC_ABS,"dec",ABSOLUTE,3,emul_dec
-OP_BBS4_REL,"bbs4",ZPR,2,NULL
-OP_BNE_REL,"bne",RELATIVE,2,NULL
-OP_CMP_IZPY,"cmp",IZPY,2,NULL
-OP_CMP_IZP,"cmp",IZP,2,NULL
-OP_NOPI_D4,"nop",IMPLIED,1,NULL
-OP_NOPI_D5,"nop",ZPX,2,NULL
-OP_CMP_ZPX,"cmp",ZPX,2,NULL
-OP_DEC_ZPX,"dec",ZPX,2,emul_dec
-OP_SMB5_ZP,"smb5",ZP,2,NULL
-OP_CLD,"cld",IMPLIED,1,NULL
-OP_CMP_ABSY,"cmp",ABSOLUTEY,3,NULL
-OP_PHX,"phx",IMPLIED,1,emul_phx
-OP_STP,"stp",IMPLIED,1,emul_stp
-OP_NOPI_DD,"nop",ABSOLUTE,3,NULL
-OP_CMP_ABSX,"cmp",ABSOLUTEX,3,NULL
-OP_DEC_ABSX,"dec",ABSOLUTEX,3,emul_dec
-OP_BBS5_REL,"bbs5",ZPR,2,NULL
-OP_CPX_IMM,"cpx",IMMEDIATE,2,NULL
-OP_SBC_IZPX,"sbc",IZPX,2,NULL
-OP_NOPI_E3,"nop",IMMEDIATE,2,NULL
-OP_NOPI_E4,"nop",IMPLIED,1,NULL
-OP_CPX_ZP,"cpx",ZP,2,NULL
-OP_SBC_ZP,"sbc",ZP,2,NULL
-OP_INC_ZP,"inc",ZP,2,emul_inc
-OP_SMB6_ZP,"smb6",ZP,2,NULL
-OP_INX,"inx",IMPLIED,1,emul_inx
-OP_SBC_IMM,"sbc",IMMEDIATE,2,NULL
-OP_NOP,"nop",IMPLIED,1,emul_nop
-OP_NOPI_EC,"nop",IMPLIED,1,NULL
-OP_CPX_ABS,"cpx",ABSOLUTE,3,NULL
-OP_SBC_ABS,"sbc",ABSOLUTE,3,NULL
-OP_INC_ABS,"inc",ABSOLUTE,3,emul_inc
-OP_BBS6_REL,"bbs6",ZPR,2,NULL
-OP_BEQ_REL,"beq",RELATIVE,2,NULL
-OP_SBC_IZPY,"sbc",IZPY,2,NULL
-OP_SBC_IZP,"sbc",IZP,2,NULL
-OP_NOPI_F4,"nop",IMPLIED,1,NULL
-OP_NOPI_F5,"nop",ZPX,2,NULL
-OP_SBC_ZPX,"sbc",ZPX,2,NULL
-OP_INC_ZPX,"inc",ZPX,2,emul_inc
-OP_SMB7_ZP,"smb7",ZP,2,NULL
-OP_SED,"sed",IMPLIED,1,NULL
-OP_SBC_ABSY,"sbc",ABSOLUTEY,3,NULL
-OP_PLX,"plx",IMPLIED,1,emul_plx
-OP_NOPI_FC,"nop",IMPLIED,1,NULL
-OP_NOPI_FD,"nop",ABSOLUTE,3,NULL
-OP_SBC_ABSX,"sbc",ABSOLUTEX,3,NULL
-OP_INC_ABSX,"inc",ABSOLUTEX,3,emul_inc
-OP_BBS7_REL,"bbs7",ZPR,2,NULL
+opcode_id,mnemonic,addressing,size,emulation,modify_pc
+OP_BRK,"brk",IMPLIED,1,NULL,false
+OP_ORA_IZPX,"ora",IZPX,2,emul_ora,false
+OP_NOPI_3,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_4,"nop",IMPLIED,1,NULL,false
+OP_TSB_ZP,"tsb",ZP,2,NULL,false
+OP_ORA_ZP,"ora",ZP,2,emul_ora,false
+OP_ASL_ZP,"asl",ZP,2,emul_asl,false
+OP_RMB0_ZP,"rmb0",ZP,2,emul_rmb0,false
+OP_PHP,"php",IMPLIED,1,emul_php,false
+OP_ORA_IMM,"ora",IMMEDIATE,2,emul_ora,false
+OP_ASL,"asl",ACCUMULATOR,1,emul_asl,false
+OP_NOPI_C,"nop",IMPLIED,1,NULL,false
+OP_TSB_ABS,"tsb",ABSOLUTE,3,NULL,false
+OP_ORA_ABS,"ora",ABSOLUTE,3,emul_ora,false
+OP_ASL_ABS,"asl",ABSOLUTE,3,emul_asl,false
+OP_BBR0_REL,"bbr0",ZPR,2,NULL,true
+OP_BPL_REL,"bpl",RELATIVE,2,NULL,true
+OP_ORA_IZPY,"ora",IZPY,2,emul_ora,false
+OP_ORA_IZP,"ora",IZP,2,emul_ora,false
+OP_NOPI_14,"nop",IMPLIED,1,NULL,false
+OP_TRB_ZP,"trb",ZP,2,NULL,false
+OP_ORA_ZPX,"ora",ZPX,2,emul_ora,false
+OP_ASL_ZPX,"asl",ZPX,2,emul_asl,false
+OP_RMB1_ZP,"rmb1",ZP,1,emul_rmb1,false
+OP_CLC,"clc",IMPLIED,1,emul_clc,false
+OP_ORA_ABSY,"ora",ABSOLUTEY,3,emul_ora,false
+OP_INC,"inc",ACCUMULATOR,1,emul_inc,false
+OP_NOPI_1C,"nop",IMPLIED,1,NULL,false
+OP_TRB_ABS,"trb",ABSOLUTE,3,NULL,false
+OP_ORA_ABSX,"ora",ABSOLUTEX,3,emul_ora,false
+OP_ASL_ABSX,"asl",ABSOLUTEX,3,emul_asl,false
+OP_BBR1_REL,"bbr1",ZPR,2,NULL,true
+OP_JSR,"jsr",ABSOLUTE,3,NULL,true
+OP_AND_IZPX,"and",IZPX,2,emul_and,false
+OP_NOPI_23,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_24,"nop",IMPLIED,1,NULL,false
+OP_BIT_ZP,"bit",ZP,2,emul_bit,false
+OP_AND_ZP,"and",ZP,2,emul_and,false
+OP_ROL_ZP,"rol",ZP,2,emul_rol,false
+OP_RMB2_ZP,"rmb2",ZP,2,emul_rmb2,false
+OP_PLP,"plp",IMPLIED,1,emul_plp,false
+OP_AND_IMM,"and",IMMEDIATE,2,emul_and,false
+OP_ROL,"rol",ACCUMULATOR,1,emul_rol,false
+OP_NOPI_2C,"nop",IMPLIED,1,NULL,false
+OP_BIT_ABS,"bit",ABSOLUTE,3,emul_bit,false
+OP_AND_ABS,"and",ABSOLUTE,3,emul_and,false
+OP_ROL_ABS,"rol",ABSOLUTE,3,emul_rol,false
+OP_BBR2_REL,"bbr2",ZPR,2,NULL,true
+OP_BMI_REL,"bmi",RELATIVE,2,NULL,true
+OP_AND_IZPY,"and",IZPY,2,emul_and,false
+OP_AND_IZP,"and",IZP,2,emul_and,false
+OP_NOPI_34,"nop",IMPLIED,1,NULL,false
+OP_BIT_ZPX,"bit",ZPX,2,emul_bit,false
+OP_AND_ZPX,"and",ZPX,2,emul_and,false
+OP_ROL_ZPX,"rol",ZPX,2,emul_rol,false
+OP_RMB3_ZP,"rmb3",ZP,2,emul_rmb3,false
+OP_SEC,"sec",IMPLIED,1,emul_sec,false
+OP_AND_ABSY,"and",ABSOLUTEY,3,emul_and,false
+OP_DEC,"dec",ACCUMULATOR,1,emul_dec,false
+OP_NOPI_3C,"nop",IMPLIED,1,NULL,false
+OP_BIT_ABSX,"bit",ABSOLUTEX,3,emul_bit,false
+OP_AND_ABSX,"and",ABSOLUTEX,3,emul_and,false
+OP_ROL_ABSX,"rol",ABSOLUTEX,3,emul_rol,false
+OP_BBR3_REL,"bbr3",ZPR,2,NULL,true
+OP_RTI,"rti",IMPLIED,1,NULL,false
+OP_EOR_IZPX,"eor",IZPX,2,emul_eor,false
+OP_NOPI_43,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_44,"nop",IMPLIED,1,NULL,false
+OP_NOPI_45,"nop",ZP,2,NULL,false
+OP_EOR_ZP,"eor",ZP,2,emul_eor,false
+OP_LSR_ZP,"lsr",ZP,2,emul_lsr,false
+OP_RMB4_ZP,"rmb4",ZP,2,emul_rmb4,false
+OP_PHA,"pha",IMPLIED,1,emul_pha,false
+OP_EOR_IMM,"eor",IMMEDIATE,2,emul_eor,false
+OP_LSR,"lsr",ACCUMULATOR,1,emul_lsr,false
+OP_NOPI_4C,"nop",IMPLIED,1,NULL,false
+OP_JMP_ABS,"jmp",ABSOLUTE,3,NULL,true
+OP_EOR_ABS,"eor",ABSOLUTE,3,emul_eor,false
+OP_LSR_ABS,"lsr",ABSOLUTE,3,emul_lsr,false
+OP_BBR4_REL,"bbr4",ZPR,2,NULL,true
+OP_BVC_REL,"bvc",RELATIVE,2,NULL,true
+OP_EOR_IZPY,"eor",IZPY,2,emul_eor,false
+OP_EOR_IZP,"eor",IZP,2,emul_eor,false
+OP_NOPI_54,"nop",IMPLIED,1,NULL,false
+OP_NOPI_55,"nop",ZPX,2,NULL,false
+OP_EOR_ZPX,"eor",ZPX,2,emul_eor,false
+OP_LSR_ZPX,"lsr",ZPX,2,emul_lsr,false
+OP_RMB5_ZP,"rmb5",ZP,2,emul_rmb5,false
+OP_CLI,"cli",IMPLIED,1,NULL,false
+OP_EOR_ABSY,"eor",ABSOLUTEY,3,emul_eor,false
+OP_PHY,"phy",IMPLIED,1,emul_phy,false
+OP_NOPI_5C,"nop",IMPLIED,1,NULL,false
+OP_NOPI_5D,"nop",ABSOLUTE,3,NULL,false
+OP_EOR_ABSX,"eor",ABSOLUTEX,3,emul_eor,false
+OP_LSR_ABSX,"lsr",ABSOLUTEX,3,emul_lsr,false
+OP_BBR5_REL,"bbr5",ZPR,2,NULL,true
+OP_RTS,"rts",IMPLIED,1,NULL,false
+OP_ADC_IZPX,"adc",IZPX,2,NULL,false
+OP_NOPI_63,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_64,"nop",IMPLIED,1,NULL,false
+OP_STZ_ZP,"stz",ZP,2,emul_stz,false
+OP_ADC_ZP,"adc",ZP,2,NULL,false
+OP_ROR_ZP,"ror",ZP,2,emul_ror,false
+OP_RMB6_ZP,"rmb6",ZP,2,emul_rmb6,false
+OP_PLA,"pla",IMPLIED,1,emul_pla,false
+OP_ADC_IMM,"adc",IMMEDIATE,2,NULL,false
+OP_ROR,"ror",ACCUMULATOR,1,emul_ror,false
+OP_NOPI_6C,"nop",IMPLIED,1,NULL,false
+OP_JMP_IABS,"jmp",IABSOLUTE,3,NULL,true
+OP_ADC_ABS,"adc",ABSOLUTE,3,NULL,false
+OP_ROR_ABS,"ror",ABSOLUTE,3,emul_ror,false
+OP_BBR6_REL,"bbr6",ZPR,2,NULL,true
+OP_BVS_REL,"bvs",RELATIVE,2,NULL,true
+OP_ADC_IZPY,"adc",IZPY,2,NULL,false
+OP_ADC_IZP,"adc",IZP,2,NULL,false
+OP_NOPI_74,"nop",IMPLIED,1,NULL,false
+OP_STZ_ZPX,"stz",ZPX,2,emul_stz,false
+OP_ADC_ZPX,"adc",ZPX,2,NULL,false
+OP_ROR_ZPX,"ror",ZPX,2,emul_ror,false
+OP_RMB7_ZP,"rmb7",ZP,2,emul_rmb7,false
+OP_SEI,"sei",IMPLIED,1,NULL,false
+OP_ADC_ABSY,"adc",ABSOLUTEY,3,NULL,false
+OP_PLY,"ply",IMPLIED,1,emul_ply,false
+OP_NOPI_7C,"nop",IMPLIED,1,NULL,false
+OP_JMP_IABSX,"jmp",IABSOLUTEX,3,NULL,true
+OP_ADC_ABSX,"adc",ABSOLUTEX,3,NULL,false
+OP_ROR_ABSX,"ror",ABSOLUTEX,3,emul_ror,false
+OP_BBR7_REL,"bbr7",ZPR,2,NULL,true
+OP_BRA_REL,"bra",RELATIVE,2,NULL,true
+OP_STA_IZPX,"sta",IZPX,2,emul_sta,false
+OP_NOPI_83,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_84,"nop",IMPLIED,1,NULL,false
+OP_STY_ZP,"sty",ZP,2,emul_sty,false
+OP_STA_ZP,"sta",ZP,2,emul_sta,false
+OP_STX_ZP,"stx",ZP,2,emul_stx,false
+OP_SMB0_ZP,"smb0",ZP,2,NULL,false
+OP_DEY,"dey",IMPLIED,1,emul_dey,false
+OP_BIT_IMM,"bit",IMMEDIATE,2,emul_bit,false
+OP_TXA,"txa",IMPLIED,1,emul_txa,false
+OP_NOPI_8C,"nop",IMPLIED,1,NULL,false
+OP_STY_ABS,"sty",ABSOLUTE,3,emul_sty,false
+OP_STA_ABS,"sta",ABSOLUTE,3,emul_sta,false
+OP_STX_ABS,"stx",ABSOLUTE,3,emul_stx,false
+OP_BBS0_REL,"bbs0",ZPR,2,NULL,true
+OP_BCC_REL,"bcc",RELATIVE,2,NULL,true
+OP_STA_IZPY,"sta",IZPY,2,emul_sta,false
+OP_STA_IZP,"sta",IZP,2,emul_sta,false
+OP_NOPI_94,"nop",IMPLIED,1,NULL,false
+OP_STY_ZPX,"sty",ZPX,2,emul_sty,false
+OP_STA_ZPX,"sta",ZPX,2,emul_sta,false
+OP_STX_ZPY,"stx",ZPY,2,emul_stx,false
+OP_SMB1_ZP,"smb1",ZP,2,NULL,false
+OP_TYA,"tya",IMPLIED,1,emul_tya,false
+OP_STA_ABSY,"sta",ABSOLUTEY,3,emul_sta,false
+OP_TXS,"txs",IMPLIED,1,emul_txs,false
+OP_NOPI_9C,"nop",IMPLIED,1,NULL,false
+OP_STZ_ABS,"stz",ABSOLUTE,3,emul_stz,false
+OP_STA_ABSX,"sta",ABSOLUTEX,3,emul_sta,false
+OP_STZ_ABSX,"stz",ABSOLUTEX,3,emul_stz,false
+OP_BBS1_REL,"bbs1",ZPR,2,NULL,true
+OP_LDY_IMM,"ldy",IMMEDIATE,2,emul_ldy,false
+OP_LDA_IZPX,"lda",IZPX,2,emul_lda,false
+OP_LDX_IMM,"ldx",IMMEDIATE,2,emul_ldx,false
+OP_NOPI_A4,"nop",IMPLIED,1,NULL,false
+OP_LDY_ZP,"ldy",ZP,2,emul_ldy,false
+OP_LDA_ZP,"lda",ZP,2,emul_lda,false
+OP_LDX_ZP,"ldx",ZP,2,emul_ldx,false
+OP_SMB2_ZP,"smb2",ZP,2,NULL,false
+OP_TAY,"tay",IMPLIED,1,emul_tay,false
+OP_LDA_IMM,"lda",IMMEDIATE,2,emul_lda,false
+OP_TAX,"tax",IMPLIED,1,emul_tax,false
+OP_NOPI_AC,"nop",IMPLIED,1,NULL,false
+OP_LDY_ABS,"ldy",ABSOLUTE,3,emul_ldy,false
+OP_LDA_ABS,"lda",ABSOLUTE,3,emul_lda,false
+OP_LDX_ABS,"ldx",ABSOLUTE,3,emul_ldx,false
+OP_BBS2_REL,"bbs2",ZPR,2,NULL,true
+OP_BCS_REL,"bcs",RELATIVE,2,NULL,true
+OP_LDA_IZPY,"lda",IZPY,2,emul_lda,false
+OP_LDA_IZP,"lda",IZP,2,emul_lda,false
+OP_NOPI_B4,"nop",IMPLIED,1,NULL,false
+OP_LDY_ZPX,"ldy",ZPX,2,emul_ldy,false
+OP_LDA_ZPX,"lda",ZPX,2,emul_lda,false
+OP_LDX_ZPY,"ldx",ZPY,1,emul_ldx,false
+OP_SMB3_ZP,"smb3",ZP,2,NULL,false
+OP_CLV,"clv",IMPLIED,1,NULL,false
+OP_LDA_ABSY,"lda",ABSOLUTEY,3,emul_lda,false
+OP_TSX,"tsx",IMPLIED,1,emul_tsx,false
+OP_NOPI_BC,"nop",IMPLIED,1,NULL,false
+OP_LDY_ABSX,"ldy",ABSOLUTEX,3,emul_ldy,false
+OP_LDA_ABSX,"lda",ABSOLUTEX,3,emul_lda,false
+OP_LDX_ABSY,"ldx",ABSOLUTEY,3,emul_ldx,false
+OP_BBS3_REL,"bbs3",ZPR,2,NULL,true
+OP_CPY_IMM,"cpy",IMMEDIATE,2,NULL,false
+OP_CMP_IZPX,"cmp",IZPX,2,NULL,false
+OP_NOPI_C3,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_C4,"nop",IMPLIED,1,NULL,false
+OP_CPY_ZP,"cpy",ZP,2,NULL,false
+OP_CMP_ZP,"cmp",ZP,2,NULL,false
+OP_DEC_ZP,"dec",ZP,2,emul_dec,false
+OP_SMB4_ZP,"smb4",ZP,2,NULL,false
+OP_INY,"iny",IMPLIED,1,emul_iny,false
+OP_CMP_IMM,"cmp",IMMEDIATE,2,NULL,false
+OP_DEX,"dex",IMPLIED,1,emul_dex,false
+OP_WAI,"wai",IMPLIED,1,NULL,false
+OP_CPY_ABS,"cpy",ABSOLUTE,3,NULL,false
+OP_CMP_ABS,"cmp",ABSOLUTE,3,NULL,false
+OP_DEC_ABS,"dec",ABSOLUTE,3,emul_dec,false
+OP_BBS4_REL,"bbs4",ZPR,2,NULL,true
+OP_BNE_REL,"bne",RELATIVE,2,NULL,true
+OP_CMP_IZPY,"cmp",IZPY,2,NULL,false
+OP_CMP_IZP,"cmp",IZP,2,NULL,false
+OP_NOPI_D4,"nop",IMPLIED,1,NULL,false
+OP_NOPI_D5,"nop",ZPX,2,NULL,false
+OP_CMP_ZPX,"cmp",ZPX,2,NULL,false
+OP_DEC_ZPX,"dec",ZPX,2,emul_dec,false
+OP_SMB5_ZP,"smb5",ZP,2,NULL,false
+OP_CLD,"cld",IMPLIED,1,NULL,false
+OP_CMP_ABSY,"cmp",ABSOLUTEY,3,NULL,false
+OP_PHX,"phx",IMPLIED,1,emul_phx,false
+OP_STP,"stp",IMPLIED,1,emul_stp,false
+OP_NOPI_DD,"nop",ABSOLUTE,3,NULL,false
+OP_CMP_ABSX,"cmp",ABSOLUTEX,3,NULL,false
+OP_DEC_ABSX,"dec",ABSOLUTEX,3,emul_dec,false
+OP_BBS5_REL,"bbs5",ZPR,2,NULL,true
+OP_CPX_IMM,"cpx",IMMEDIATE,2,NULL,false
+OP_SBC_IZPX,"sbc",IZPX,2,NULL,false
+OP_NOPI_E3,"nop",IMMEDIATE,2,NULL,false
+OP_NOPI_E4,"nop",IMPLIED,1,NULL,false
+OP_CPX_ZP,"cpx",ZP,2,NULL,false
+OP_SBC_ZP,"sbc",ZP,2,NULL,false
+OP_INC_ZP,"inc",ZP,2,emul_inc,false
+OP_SMB6_ZP,"smb6",ZP,2,NULL,false
+OP_INX,"inx",IMPLIED,1,emul_inx,false
+OP_SBC_IMM,"sbc",IMMEDIATE,2,NULL,false
+OP_NOP,"nop",IMPLIED,1,emul_nop,false
+OP_NOPI_EC,"nop",IMPLIED,1,NULL,false
+OP_CPX_ABS,"cpx",ABSOLUTE,3,NULL,false
+OP_SBC_ABS,"sbc",ABSOLUTE,3,NULL,false
+OP_INC_ABS,"inc",ABSOLUTE,3,emul_inc,false
+OP_BBS6_REL,"bbs6",ZPR,2,NULL,true
+OP_BEQ_REL,"beq",RELATIVE,2,NULL,true
+OP_SBC_IZPY,"sbc",IZPY,2,NULL,false
+OP_SBC_IZP,"sbc",IZP,2,NULL,false
+OP_NOPI_F4,"nop",IMPLIED,1,NULL,false
+OP_NOPI_F5,"nop",ZPX,2,NULL,false
+OP_SBC_ZPX,"sbc",ZPX,2,NULL,false
+OP_INC_ZPX,"inc",ZPX,2,emul_inc,false
+OP_SMB7_ZP,"smb7",ZP,2,NULL,false
+OP_SED,"sed",IMPLIED,1,NULL,false
+OP_SBC_ABSY,"sbc",ABSOLUTEY,3,NULL,false
+OP_PLX,"plx",IMPLIED,1,emul_plx,false
+OP_NOPI_FC,"nop",IMPLIED,1,NULL,false
+OP_NOPI_FD,"nop",ABSOLUTE,3,NULL,false
+OP_SBC_ABSX,"sbc",ABSOLUTEX,3,NULL,false
+OP_INC_ABSX,"inc",ABSOLUTEX,3,emul_inc,false
+OP_BBS7_REL,"bbs7",ZPR,2,NULL,true
diff --git a/src/instruction.c b/src/instruction.c
index 054e1ff..1a70512 100644
--- a/src/instruction.c
+++ b/src/instruction.c
@@ -327,3 +327,10 @@ program_counter_increment(rk65c02emu_t *e, instrdef_t *id)
 	e->regs.PC += id->size;
 }	
 
+/* check whether given instruction modify program counter */
+bool
+instruction_modify_pc(instrdef_t *id)
+{
+	return id->modify_pc;
+}
+
diff --git a/src/instruction.h b/src/instruction.h
index 106e83f..29cf621 100644
--- a/src/instruction.h
+++ b/src/instruction.h
@@ -31,11 +31,12 @@ struct instruction {
 typedef struct instruction instruction_t;
 
 struct instrdef {
-	uint8_t opcode;
+	uint8_t opcode;		/* opcode, normally same as in instruction */
 	const char *mnemonic;
 	addressing_t mode;
 	uint8_t size;
 	void (*emul)(rk65c02emu_t *e, void *id, instruction_t *i);
+	bool modify_pc;
 };
 
 typedef struct instrdef instrdef_t;
@@ -51,5 +52,6 @@ void instruction_status_adjust_negative(rk65c02emu_t *, uint8_t);
 void stack_push(rk65c02emu_t *, uint8_t);
 uint8_t stack_pop(rk65c02emu_t *);
 void program_counter_increment(rk65c02emu_t *, instrdef_t *);
+bool instruction_modify_pc(instrdef_t *);
 
 #endif /* _INSTRUCTION_H_ */
diff --git a/src/rk65c02.c b/src/rk65c02.c
index b388f53..1c1dba6 100644
--- a/src/rk65c02.c
+++ b/src/rk65c02.c
@@ -46,8 +46,8 @@ rk65c02_exec(rk65c02emu_t *e)
 
 	if (id.emul != NULL) {
 		id.emul(e, &id, &i);
-		/* if (!instruction_modify_pc) */
-		program_counter_increment(e, &id);
+		if (!instruction_modify_pc(&id)) 
+			program_counter_increment(e, &id);
 	} else {
 		printf("unimplemented opcode %X @ %X\n", i.opcode,
 		    e->regs.PC);