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First preparations for configurable CPU definitions

This commit is contained in:
tudnai 2020-07-27 23:55:55 -07:00
parent 675959e389
commit c948865ece
5 changed files with 419 additions and 3 deletions
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4
A2Mac.xcodeproj/project.pbxproj
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@ -310,6 +310,8 @@
320B3FC324AD88B0005EA133 /* power.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = power.png; sourceTree = "<group>"; };
320B4FC024B182DD00070038 /* Apple Disk II.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "Apple Disk II.png"; sourceTree = "<group>"; };
320F2A8724CFD74000671B35 /* Steve2Icon.icns */ = {isa = PBXFileReference; lastKnownFileType = image.icns; path = Steve2Icon.icns; sourceTree = "<group>"; };
320F2A8924CFFBE300671B35 /* 6502_std.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = 6502_std.h; sourceTree = "<group>"; };
320F2A8A24D0001600671B35 /* 6502_und.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = 6502_und.h; sourceTree = "<group>"; };
323D042D248980600086A901 /* Preferences.storyboard */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; path = Preferences.storyboard; sourceTree = "<group>"; };
323D042F24898AB70086A901 /* PreferencesViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesViewController.swift; sourceTree = "<group>"; };
323D04312489BFD80086A901 /* PreferencesWindowController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesWindowController.swift; sourceTree = "<group>"; };
@ -675,6 +677,8 @@
32439F7522ECD8AD0077AAE0 /* instructions */,
32439F8522ECD8AD0077AAE0 /* 6502.h */,
32439F7422ECD8AD0077AAE0 /* 6502.c */,
320F2A8924CFFBE300671B35 /* 6502_std.h */,
320F2A8A24D0001600671B35 /* 6502_und.h */,
32440B69247CA1CE000F9DA1 /* 65C02.c */,
32440B67247CA1AF000F9DA1 /* 6502_vanilla.c */,
);

4
A2Mac.xcodeproj/xcshareddata/xcschemes/A2Mac.xcscheme
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@ -61,8 +61,8 @@
</TestAction>
<LaunchAction
buildConfiguration = "Release"
selectedDebuggerIdentifier = ""
selectedLauncherIdentifier = "Xcode.IDEFoundation.Launcher.PosixSpawn"
selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
disableMainThreadChecker = "YES"
launchStyle = "0"
useCustomWorkingDirectory = "NO"

2
src/cpu/6502.c
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@ -495,7 +495,7 @@ INLINE int m6502_Step() {
case 0xF7: ISB( addr_zp_X() ); return 6; // ISB* zpx 6 (undocumented)
case 0xF8: SED(); return 2; // SED
case 0xF9: SBC( src_abs_Y() ); return 4+1; // SBC abs,Y
case 0xFA: NOP(); return 2; // NOP
case 0xFA: NOP(); return 2; // NOP (undocumented)
case 0xFB: ISB( addr_abs_Y() ); return 7; // ISB* aby 7 (undocumented)
case 0xFC: NOP(); src_abs_X(); return 4; // NOP* abx 4 (undocumented)
case 0xFD: SBC( src_abs_X() ); return 4+1; // SBC abs,X

229
src/cpu/6502_std.h Normal file
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@ -0,0 +1,229 @@
//
// 6502_std.h
// A2Mac
//
// Created by Tamas Rudnai on 7/27/20.
// Copyright © 2020 GameAlloy. All rights reserved.
//
#ifndef _502_std_h
#define _502_std_h
case 0x00: BRK(); return 7; // BRK
case 0x01: ORA( src_X_ind() ); return 6; // ORA X,ind
case 0x05: ORA( src_zp() ); return 3; // ORA zpg
case 0x06: ASL( addr_zp() ); return 5; // ASL zpg
case 0x08: PHP(); return 3; // PHP
case 0x09: ORA( imm() ); return 2; // ORA imm
case 0x0A: ASLA(); return 2; // ASL A
case 0x0D: ORA( src_abs() ); return 4; // ORA abs
case 0x0E: ASL( addr_abs() ); return 6; // ASL abs
case 0x10: BPL( rel_addr() ); return 3; // BPL rel
case 0x11: ORA( src_ind_Y() ); return 5; // ORA ind,Y
case 0x15: ORA( src_zp_X() ); return 4; // ORA zpg,X
case 0x16: ASL( addr_zp_X() ); return 6; // ASL zpg,X
case 0x18: CLC(); return 2; // CLC
case 0x19: ORA( src_abs_Y() ); return 4+1; // ORA abs,Y
case 0x1D: ORA( src_abs_X() ); return 4+1; // ORA abs,X
case 0x1E: ASL( addr_abs_X() ); return 7; // ASL abs,X
case 0x20: JSR( abs_addr() ); return 6; // JSR abs
case 0x21: AND( src_X_ind() ); return 6; // AND X,ind
case 0x24: BIT( src_zp() ); return 3; // BIT zpg
case 0x25: AND( src_zp() ); return 3; // AND zpg
case 0x26: ROL( addr_zp() ); return 5; // ROL zpg
case 0x28: PLP(); return 4; // PLP
case 0x29: AND( imm() ); return 2; // AND imm
case 0x2A: ROLA(); return 2; // ROL A
case 0x2C: BIT( src_abs() ); return 4; // BIT abs
case 0x2D: AND( src_abs() ); return 4; // AND abs
case 0x2E: ROL( addr_abs() ); return 6; // ROL abs
case 0x30: BMI( rel_addr() ); return 3; // BMI rel
case 0x31: AND( src_ind_Y() ); return 5; // AND ind,Y
case 0x35: AND( src_zp_X() ); return 4; // AND zpg,X
case 0x36: ROL( addr_zp_X() ); return 6; // ROL zpg,X
case 0x38: SEC(); return 2; // SEC
case 0x39: AND( src_abs_Y() ); return 4+1; // AND abs,Y
case 0x3D: AND( src_abs_X() ); return 4+1; // AND abs,X
case 0x3E: ROL( addr_abs_X() ); return 7; // ROL abs,X
case 0x40: RTI(); return 6; // RTI
case 0x41: EOR( src_X_ind() ); return 6; // EOR X,ind
case 0x45: EOR( src_zp() ); return 3; // EOR zpg
case 0x46: LSR( addr_zp() ); return 5; // LSR zpg
case 0x48: PHA(); return 3; // PHA
case 0x49: EOR( imm() ); return 2; // EOR imm
case 0x4A: LSRA(); return 2; // LSR A
case 0x4C: JMP( abs_addr() ); return 3; // JMP abs
case 0x4D: EOR( src_abs() ); return 4; // EOR abs
case 0x4E: LSR( addr_abs() ); return 6; // LSR abs
case 0x50: BVC( rel_addr() ); return 3; // BVC rel
case 0x51: EOR( src_ind_Y() ); return 5; // EOR ind,Y
case 0x55: EOR( src_zp_X() ); return 4; // AND zpg,X
case 0x56: LSR( addr_zp_X() ); return 6; // LSR zpg,X
case 0x58: CLI(); return 2; // CLI
case 0x59: EOR( src_abs_Y() ); return 4+1; // EOR abs,Y
case 0x5D: EOR( src_abs_X() ); return 4+1; // EOR abs,X
case 0x5E: LSR( addr_abs_X() ); return 7; // LSR abs,X
case 0x60: RTS(); return 6; // RTS
case 0x61: ADC( src_X_ind() ); return 6; // ADC X,ind
case 0x65: ADC( src_zp() ); return 3; // ADC zpg
case 0x66: ROR( addr_zp() ); return 5; // ROR zpg
case 0x68: PLA(); return 4; // PLA
case 0x69: ADC( imm() ); return 2; // ADC imm
case 0x6A: RORA(); return 2; // ROR A
case 0x6C: JMP( ind_addr() ); return 5; // JMP ind
case 0x6D: ADC( src_abs() ); return 4; // ADC abs
case 0x6E: ROR( addr_abs() ); return 6; // ROR abs
case 0x70: BVS( rel_addr() ); return 3; // BVS rel
case 0x71: ADC( src_ind_Y() ); return 5; // ADC ind,Y
case 0x75: ADC( src_zp_X() ); return 4; // ADC zpg,X
case 0x76: ROR( addr_zp_X() ); return 6; // ROR zpg,X
case 0x78: SEI(); return 2; // SEI
case 0x79: ADC( src_abs_Y() ); return 4+1; // ADC abs,Y
case 0x7D: ADC( src_abs_X() ); return 4+1; // ADC abs,X
case 0x7E: ROR( addr_abs_X() ); return 7; // ROR abs,X
case 0x81: STA( addr_ind_X() ) ; return 6; // STA X,ind
case 0x84: STY( addr_zp() ); return 3; // STY zpg
case 0x85: STA( addr_zp() ); return 3; // STA zpg
case 0x86: STX( addr_zp() ); return 3; // STX zpg
case 0x88: DEY(); return 2; // DEY
case 0x8A: TXA(); return 2; // TXA
case 0x8C: STY( addr_abs() ); return 4; // STY abs
case 0x8D: STA( addr_abs() ); return 4; // STA abs
case 0x8E: STX( addr_abs() ); return 4; // STX abs
case 0x90: BCC( rel_addr() ); return 3; // BCC rel
case 0x91: STA( addr_ind_Y() ); return 6; // STA ind,Y
case 0x94: STY( addr_zp_X() ); return 4; // STY zpg,X
case 0x95: STA( addr_zp_X() ); return 4; // STA zpg,X
case 0x96: STX( addr_zp_Y() ); return 4; // STX zpg,Y
case 0x98: TYA(); return 2; // TYA
case 0x99: STA( addr_abs_Y() ); return 5; // STA abs,Y
case 0x9A: TXS(); return 2; // TXS
case 0x9D: STA( addr_abs_X() ); return 5; // STA abs,X
case 0xA0: LDY( imm() ); return 2; // LDY imm
case 0xA1: LDA( src_X_ind() ) ; return 6; // LDA X,ind
case 0xA2: LDX( imm() ); return 2; // LDX imm
case 0xA4: LDY( src_zp() ); return 3; // LDY zpg
case 0xA5: LDA( src_zp() ); return 3; // LDA zpg
case 0xA6: LDX( src_zp() ); return 3; // LDX zpg
case 0xA8: TAY(); return 2; // TAY
case 0xA9: LDA( imm() ); return 2; // LDA imm
case 0xAA: TAX(); return 2; // TAX
case 0xAC: LDY( src_abs() ); return 4; // LDY abs
case 0xAD: LDA( src_abs() ); return 4; // LDA abs
case 0xAE: LDX( src_abs() ); return 4; // LDX abs
case 0xB0: BCS( rel_addr() ); return 3; // BCS rel
case 0xB1: LDA( src_ind_Y() ); return 5; // LDA ind,Y
case 0xB4: LDY( src_zp_X() ); return 4+1; // LDY zpg,X
case 0xB5: LDA( src_zp_X() ); return 4+1; // LDA zpg,X
case 0xB6: LDX( src_zp_Y() ); return 4+1; // LDX zpg,Y
case 0xB8: CLV(); return 2; // CLV
case 0xB9: LDA( src_abs_Y() ); return 4; // LDA abs,Y
case 0xBA: TSX(); return 2; // TSX
case 0xBC: LDY( src_abs_X() ); return 4; // LDY abs,X
case 0xBD: LDA( src_abs_X() ); return 4; // LDA abs,X
case 0xBE: LDX( src_abs_Y() ); return 4;
// LDX abs,Y
case 0xC0: CPY( imm() ); return 2; // CPY imm
case 0xC1: CMP( src_X_ind() ) ; return 6; // LDA X,ind
case 0xC4: CPY( src_zp() ); return 3; // CPY zpg
case 0xC5: CMP( src_zp() ); return 3; // CMP zpg
case 0xC6: DEC( addr_zp() ); return 5; // DEC zpg
case 0xC8: INY(); return 2; // INY
case 0xC9: CMP( imm() ); return 2; // CMP imm
case 0xCA: DEX(); return 2; // DEX
case 0xCC: CPY( src_abs() ); return 4; // CPY abs
case 0xCD: CMP( src_abs() ); return 4; // CMP abs
case 0xCE: DEC( addr_abs() ); return 6; // DEC abs
case 0xD0: BNE( rel_addr() ); return 3; // BNE rel
case 0xD1: CMP( src_ind_Y() ); return 5; // CMP ind,Y
case 0xD5: CMP( src_zp_X() ); return 4; // CMP zpg,X
case 0xD6: DEC( addr_zp_X() ); return 6; // DEC zpg,X
case 0xD8: CLD(); return 2; // CLD
case 0xD9: CMP( src_abs_Y() ); return 4; // CMP abs,Y
case 0xDD: CMP( src_abs_X() ); return 4; // CMP abs,X
case 0xDE: DEC( addr_abs_X() ); return 7; // DEC abs,X
case 0xE0: CPX( imm() ); return 2; // CPX imm
case 0xE1: SBC( src_X_ind() ) ; return 6; // SBC (X,ind)
case 0xE4: CPX( src_zp() ); return 3; // CPX zpg
case 0xE5: SBC( src_zp() ); return 3; // SBC zpg
case 0xE6: INC( addr_zp() ); return 5; // INC zpg
case 0xE8: INX(); return 2; // INX
case 0xE9: SBC( imm() ); return 2; // SBC imm
case 0xEA: NOP(); return 2; // NOP
case 0xEC: CPX( src_abs() ); return 4; // CPX abs
case 0xED: SBC( src_abs() ); return 4; // SBC abs
case 0xEE: INC( addr_abs() ); return 6; // INC abs
case 0xF0: BEQ( rel_addr() ); return 3; // BEQ rel
case 0xF1: SBC( src_ind_Y() ); return 5; // SBC ind,Y
case 0xF5: SBC( src_zp_X() ); return 4; // SBC zpg,X
case 0xF6: INC( addr_zp_X() ); return 6; // INC zpg,X
case 0xF8: SED(); return 2; // SED
case 0xF9: SBC( src_abs_Y() ); return 4+1; // SBC abs,Y
case 0xFD: SBC( src_abs_X() ); return 4+1; // SBC abs,X
case 0xFE: INC( addr_abs_X() ); return 7; // INC abs,X
#endif /* _502_std_h */

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src/cpu/6502_und.h Normal file
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@ -0,0 +1,183 @@
//
// 6502_und.h
// A2Mac
//
// Created by Tamas Rudnai on 7/27/20.
// Copyright © 2020 GameAlloy. All rights reserved.
//
#ifndef _502_und_h
#define _502_und_h
case 0x02: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x03: SLO( addr_zp_X() ); return 8; // SLO* zpg,X (undocumented)
case 0x04: NOP(); src_zp(); return 3; // NOP* zpg (undocumented)
case 0x07: SLO( addr_zp() ); return 5; // SLO* zpg (undocumented)
case 0x0B: ANC( imm() ); return 2; // ANC** imm (undocumented)
case 0x0C: NOP(); src_abs(); return 4; // NOP* (undocumented)
case 0x0F: SLO( addr_abs() ); return 6; // SLO* (undocumented)
case 0x12: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x13: SLO( addr_zp_Y() ); return 8; // SLO* zpg,Y (undocumented)
case 0x14: NOP(); addr_zp_X(); return 4; // NOP* zpg,X (undocumented)
case 0x17: SLO( addr_zp_X() ); return 6; // SLO* zpg,X (undocumented)
case 0x1A: NOP(); return 2; // NOP* (undocumented)
case 0x1B: SLO( addr_abs_Y() ); return 7; // SLO* abs,Y (undocumented)
case 0x1C: NOP(); src_abs_X(); return 4; // NOP* (undocumented)
case 0x1F: SLO( addr_abs_X() ); return 7; // SLO* abs,X (undocumented)
case 0x22: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x23: RLA( addr_ind_X() ); return 8; // RLA* ind,X 8 (undocumented)
case 0x27: RLA( addr_zp() ); return 5; // RLA* zpg 5 (undocumented)
case 0x2B: ANC( imm() ); return 2; // ANC* imm 2 (undocumented)
case 0x2F: RLA( addr_abs() ); return 6; // RLA* abs 6 (undocumented)
case 0x32: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x33: RLA( addr_ind_Y() ); return 8; // RLA* izy 8 (undocumented)
case 0x34: NOP(); src_zp_X(); return 4; // NOP* zpx 4 (undocumented)
case 0x37: RLA( addr_zp_X() ); return 6; // RLA* zpx 6 (undocumented)
case 0x3A: NOP(); return 2; // NOP* 2 (undocumented)
case 0x3B: RLA( addr_abs_Y() ); return 7; // RLA* aby 7 (undocumented)
case 0x3C: NOP(); src_abs_X(); return 4; // NOP* abx 4 (undocumented)
case 0x3F: RLA( addr_abs_X() ); return 7; // RLA* abx 7 (undocumented)
case 0x42: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x43: SRE( addr_ind_X() ); return 8; // SRE* izx 8 (undocumented)
case 0x44: NOP(); return 3; // NOP* zp 3 (undocumented)
case 0x47: SRE( addr_zp() ); return 5; // SRE* zp 5 (undocumented)
case 0x4B: ASR( imm() ); return 2; // ASR* imm 2 (undocumented)
case 0x4F: SRE( abs_addr() ); return 6; // SRE* abs 6 (undocumented)
case 0x52: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x53: SRE( addr_ind_Y() ); return 8; // SRE* izy 8 (undocumented)
case 0x54: NOP(); src_zp_X(); return 4; // NOP* zpx 4 (undocumented)
case 0x57: SRE( addr_ind_X() ); return 6; // SRE* zpx 6 (undocumented)
case 0x5A: NOP(); return 2; // NOP* 2 (undocumented)
case 0x5B: SRE( addr_abs_Y() ); return 7; // SRE* aby 7 (undocumented)
case 0x5C: NOP(); src_abs_X(); return 4; // NOP* abx 4 (undocumented)
case 0x5F: SRE( addr_abs_X() ); return 7; // SRE* abx 7 (undocumented)
case 0x62: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x63: RRA( addr_ind_X() ); return 8; // RRA* izx 8 (undocumented)
case 0x64: NOP(); return 3; // NOP* zp 3 (undocumented)
case 0x67: RRA( addr_zp() ); return 5; // RRA* zp 5 (undocumented)
case 0x6B: ARC( imm() ); return 2; // ARR/ARC* imm 2 (undocumented)
case 0x6F: RRA( abs_addr() ); return 6; // RRA* abs 6 (undocumented)
case 0x72: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x73: RRA( addr_ind_Y() ); return 8; // RRA* izy 8 (undocumented)
case 0x74: NOP(); src_zp_X(); return 4; // NOP* zpx 4 (undocumented)
case 0x77: RRA( addr_zp_X() ); return 6; // RRA* zpx 6 (undocumented)
case 0x7A: NOP(); return 2; // NOP* 2 (undocumented)
case 0x7B: RRA( addr_abs_Y() ); return 7; // RRA* aby 7 (undocumented)
case 0x7C: NOP(); src_abs_X(); return 4; // NOP* abx 4 (undocumented)
case 0x7F: RRA( addr_abs_X() ); return 7; // RRA* abx 7 (undocumented)
case 0x80: NOP(); imm(); return 2; // NOP* imm 2 (undocumented)
case 0x82: NOP(); imm(); return 2; // NOP* imm 2 (undocumented)
case 0x83: SAX( addr_ind_X() ); return 6; // SAX* izx 6 (undocumented)
case 0x87: SAX( addr_zp() ); return 3; // SAX* izx 6 (undocumented)
case 0x89: NOP(); imm(); return 2; // NOP* imm (undocumented)
case 0x8B: XAA( imm() ); return 2; // XAA* imm 2 (undocumented, highly unstable!)
case 0x8F: SAX( addr_abs() ); return 4; // SAX* abs 4 (undocumented)
case 0x92: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0x93: SHA( addr_ind_Y() ); return 6; // SHA* izy 6 (undocumented, unstable)
case 0x97: SAX( addr_zp_Y() ); return 4; // SAX* izy 4 (undocumented)
case 0x9B: SAS( addr_abs_Y() ); return 5; // SAS* aby 5 (undocumented, unstable)
case 0x9C: SHY( addr_abs_X() ); return 5; // SHY* abx 5 (undocumented, unstable)
case 0x9E: SHX( addr_abs_Y() ); return 5; // SHX* aby 5 (undocumented, unstable)
case 0x9F: SAX( addr_abs_Y() ); return 5; // SAX* aby 5 (undocumented, unstable)
case 0xA3: LAX( src_X_ind() ); return 6; // LAX* izx 6 (undocumented)
case 0xA7: LAX( src_zp() ); return 3; // LAX* zpg 3 (undocumented)
case 0xAB: LAX( imm() ); return 2; // LAX* imm 2 (undocumented, highly unstable)
case 0xAF: LAX( src_abs() ); return 4; // LAX* abs 4 (undocumented)
case 0xB2: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0xB3: LAX( src_ind_Y() ); return 5; // LAX* izy 5 (undocumented)
case 0xB7: LAX( src_zp_Y() ); return 4+1; // LAX* zpy 4 (undocumented)
case 0xBB: LAS( src_abs_Y() ); return 4; // LAX* aby 4 (undocumented)
case 0xBF: LAX( src_abs_Y() ); return 4; // LAX* aby 4 (undocumented)
case 0xC2: NOP(); imm(); return 2; // NOP* imm 2 (undocumented)
case 0xC3: DCP( addr_ind_X() ); return 8; // DCP* izx 8 (undocumented)
case 0xC7: DCP( addr_zp() ); return 5; // DCP* zpg 5 (undocumented)
case 0xCB: SBX( imm() ); return 2; // SBX* imm 2 (undocumented)
case 0xCF: DCP( addr_abs() ); return 6; // DCP* abs 6 (undocumented)
case 0xD2: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0xD3: DCP( addr_ind_Y() ); return 8; // DCP* izy 8 (undocumented)
case 0xD4: NOP(); src_zp_X(); return 4; // NOP* zpx 4 (undocumented)
case 0xD7: DCP( addr_zp_X() ); return 6; // DCP* zpx 6 (undocumented)
case 0xDA: NOP(); return 2; // NOP* 2 (undocumented)
case 0xDB: DCP( addr_abs_Y() ); return 7; // DCP* aby 7 (undocumented)
case 0xDC: NOP(); src_abs_X(); return 4; // NOP* abx 4 (undocumented)
case 0xDF: DCP( addr_abs_X() ); return 7; // DCP* abx 7 (undocumented)
case 0xE2: NOP(); imm(); return 2; // NOP* imm 2 (undocumented)
case 0xE3: ISB( addr_ind_X() ); return 8; // ISB* izx 8 (undocumented)
case 0xE7: ISB( addr_zp() ); return 5; // ISB* zpg 5 (undocumented)
case 0xEB: SBC( imm() ); return 2; // SBC* imm 2 (undocumented)
case 0xEF: ISB( addr_abs() ); return 6; // ISB* abs 6 (undocumented)
case 0xF2: HLT(); return 0; // HLT* - Halts / Hangs / Jams / Kills the CPU (undocumented)
case 0xF3: ISB( addr_ind_Y() ); return 8; // ISB* izy 8 (undocumented)
case 0xF4: NOP(); src_zp_X(); return 4; // NOP* zpx 4 (undocumented)
case 0xF7: ISB( addr_zp_X() ); return 6; // ISB* zpx 6 (undocumented)
case 0xFA: NOP(); return 2; // NOP (undocumented)
case 0xFB: ISB( addr_abs_Y() ); return 7; // ISB* aby 7 (undocumented)
case 0xFC: NOP(); src_abs_X(); return 4; // NOP* abx 4 (undocumented)
case 0xFF: ISB( addr_abs_X() ); return 7; // ISB* abx 7 (undocumented)
#endif /* _502_und_h */