jac@paul.rutgers.edu (Jonathan A. Chandross) (11/19/90)
Submitted-by: None
Posting-number: Volume 1, Source:5
Archive-name: unix/simulator/koning/part02
Architecture: UNIX
Version-number: 1.00
=6502.c
-
-/*
- *6502.c -- Mostek/Rockwell/Synertek/Siliconix 6502 for Apple II Emulator
- *(C) 1989 Ben Koning [556498717 408/738-1763 ben@apple.com]
- */
-
-#include "apple.h"
-
-
-/*
- * 6502 Globals:
- */
-
-int A,X,Y,P,S;
-ADDR PPC;
-
-void CPUReset (/*_ _*/);
-void _push_ (/*_ BYTE _*/);
-BYTE _pull_ (/*_ _*/);
-BYTE _eaimm_ (/*_ _*/);
-BYTE _eazp_ (/*_ _*/);
-BYTE _eazpx_ (/*_ _*/);
-BYTE _eazpy_ (/*_ _*/);
-ADDR _eaabs_ (/*_ _*/);
-ADDR _eaabsind_ (/*_ _*/);
-ADDR _eaabsx_ (/*_ _*/);
-ADDR _eaabsy_ (/*_ _*/);
-ADDR _eaindx_ (/*_ _*/);
-ADDR _eaindy_ (/*_ _*/);
-
-
-void CPUReset ()
-{
- /* Setup registers: */
- A = X = Y = P = 0;
- S = 0xff;
-
- /* Set PPC to pointer at $FFFC: */
- PPC = MegaGetMem (0xfffc) + MegaGetMem (0xfffd) * 0x0100;
-
- /* Should execute instructions forever after this */
-}
-
-/* This internal routine pushes a byte onto the stack */
-void _push_ (byte)
-BYTE byte;
-{
- MegaPutMem ((ADDR)(0x100 + S--), byte);
- S &= 0xff;
-}
-
-/* This internal routine pulls a byte from the stack */
-BYTE _pull_ ()
-{
- S++;
- S &= 0xff;
- return MegaGetMem (0x100 + S);
-}
-
-/* This internal routine fetches an immediate operand value */
-BYTE _eaimm_ ()
-{
- register BYTE i;
-
- i = MegaGetMem (PPC++);
- PPC &= 0xffff;
- return i;
-}
-
-/* This internal routine fetches a zero-page operand address */
-BYTE _eazp_ ()
-{
- register BYTE a;
-
- a = MegaGetMem (PPC++);
- PPC &= 0xffff;
-
- return a;
-}
-
-/* This internal routine fetches a zpage,X operand address */
-BYTE _eazpx_ ()
-{
- register BYTE a;
-
- a = MegaGetMem (PPC++);
- PPC &= 0xffff;
- a += X;
- a &= 0xff;
-
- return a;
-}
-
-/* This internal routine fetches a zpage,Y operand address */
-BYTE _eazpy_ ()
-{
- register BYTE a;
-
- a = MegaGetMem (PPC++);
- PPC &= 0xffff;
- a += Y;
- a &= 0xff;
-
- return a;
-}
-
-/* This internal routine fetches an absolute operand address */
-ADDR _eaabs_ ()
-{
- register BYTE lo, hi;
-
- lo = MegaGetMem (PPC++);
- PPC &= 0xffff;
- hi = MegaGetMem (PPC++);
- PPC &= 0xffff;
-
- return lo + hi * 0x0100;
-}
-
-/* This internal routine fetches an indirect absolute operand address */
-ADDR _eaabsind_ ()
-{
- register int a, lo, hi;
-
- a = _eaabs_();
- lo = MegaGetMem ((ADDR)a++);
- a &= 0xffff;
- hi = MegaGetMem ((ADDR)a);
-
- return lo + hi * 0x0100;
-}
-
-/* This internal routine fetches an absolute,X operand address */
-ADDR _eaabsx_ ()
-{
- register int a;
-
- a = _eaabs_() + X;
-
- return (a & 0xffff); /* Not entirely correct */
-}
-
-/* This internal routine fetches an absolute,Y operand address */
-ADDR _eaabsy_ ()
-{
- register int a;
-
- a = _eaabs_() + Y;
-
- return (a & 0xffff); /* Not entirely correct */
-}
-
-/* This internal routine fetches a (zpage,X) operand address */
-ADDR _eaindx_ ()
-{
- register int a, lo, hi;
-
- a = _eazpx_();
- lo = MegaGetMem ((ADDR)a++);
- a &= 0xff;
- hi = MegaGetMem ((ADDR)a);
-
- return lo + hi * 0x0100;
-}
-
-/* This internal routine fetches a (zpage),Y operand address */
-ADDR _eaindy_ ()
-{
- register int a, lo, hi;
-
- a = _eazp_();
- lo = MegaGetMem ((ADDR)a++);
- a &= 0xff;
- hi = MegaGetMem ((ADDR)a);
-
- return ( (Y + lo + hi * 0x0100) & 0xffff ); /* Not entirely correct */
-}
-#ifdef NEVER
-/* Macros to set the P flags: */
-#define _setN_(b) if ((b)!=0) P |= 0x80; else P &= ~0x80
-#define _setV_(b) if ((b)!=0) P |= 0x40; else P &= ~0x40
-/* This bit not implemented */
-#define _setB_(b) if ((b)!=0) P |= 0x10; else P &= ~0x10
-#define _setD_(b) if ((b)!=0) P |= 0x08; else P &= ~0x08
-#define _setI_(b) if ((b)!=0) P |= 0x04; else P &= ~0x04
-#define _setZ_(b) if ((b)!=0) P |= 0x02; else P &= ~0x02
-#define _setC_(b) if ((b)!=0) P |= 0x01; else P &= ~0x01
-#endif
-/* Macros to set the P flags: */
-void _setN_(b){ if ((b)!=0) P |= 0x80; else P &= ~0x80;}
-void _setV_(b){ if ((b)!=0) P |= 0x40; else P &= ~0x40;}
-/* This bit not implemented */
-void _setB_(b){ if ((b)!=0) P |= 0x10; else P &= ~0x10;}
-void _setD_(b){ if ((b)!=0) P |= 0x08; else P &= ~0x08;}
-void _setI_(b){ if ((b)!=0) P |= 0x04; else P &= ~0x04;}
-void _setZ_(b){ if ((b)!=0) P |= 0x02; else P &= ~0x02;}
-void _setC_(b){ if ((b)!=0) P |= 0x01; else P &= ~0x01;}
-
- /* Macros to read the P flags: */
-#define _getN_ ((P & 0x80) ? 1 : 0)
-#define _getV_ ((P & 0x40) ? 1 : 0)
-/* This bit not implemented */
-#define _getB_ ((P & 0x10) ? 1 : 0)
-#define _getD_ ((P & 0x08) ? 1 : 0)
-#define _getI_ ((P & 0x04) ? 1 : 0)
-#define _getZ_ ((P & 0x02) ? 1 : 0)
-#define _getC_ ((P & 0x01) ? 1 : 0)
-
-/* This routine executes a single instruction. */
-void CPUExecute ()
-{
- register int opcode; /* Scratch: Opcode fetched */
- register int d; /* Scratch: Data byte fetched */
- register int lo; /* Scratch: Lo8 for building ptr */
- register int hi; /* Scratch: Hi8 for building ptr */
- register int al; /* Scratch: Accumulator lo nibble */
- register int ah; /* Scratch: Accumulator hi nibble */
- register int ol; /* Scratch: Operand lo nibble */
- register int oh; /* Scratch: Operand hi nibble */
-
- if (PPC == 0xc780)
- prodos();
- opcode = MegaGetMem (PPC++);
- PPC &= 0xffff;
-
- switch (opcode)
- {
- case 0x69: /* ADC #dd */
- d = _eaimm_();
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah * 16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x65: /* ADC aa */
- d = MegaGetMem ((ADDR)_eazp_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x75: /* ADC aa,X */
- d = MegaGetMem ((ADDR)_eazpx_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x6d: /* ADC aaaa */
- d = MegaGetMem (_eaabs_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x7d: /* ADC aaaa,X */
- d = MegaGetMem (_eaabsx_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah * 16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x79: /* ADC aaaa,Y */
- d = MegaGetMem (_eaabsy_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah * 16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x61: /* ADC (aa,X) */
- d = MegaGetMem (_eaindx_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah * 16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0x71: /* ADC (aa),Y */
- d = MegaGetMem (_eaindy_ ());
- if (!_getD_) {
- A = A + d + _getC_;
- _setC_ (A > 0xff);
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al = al + _getC_ + ol;
- if (al >= 10) { al -= 10; ah++; }
- ah += oh;
- _setC_ (ah >= 10);
- if (ah >= 10) ah -= 10;
- A = al + (ah * 16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
-
-
- case 0x29: /* AND #dd */
- A &= _eaimm_ ();
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x25: /* AND aa */
- A &= MegaGetMem ((ADDR)_eazp_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x35: /* AND aa,X */
- A &= MegaGetMem ((ADDR)_eazpx_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x2d: /* AND aaaa */
- A &= MegaGetMem (_eaabs_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x3d: /* AND aaaa,X */
- A &= MegaGetMem (_eaabsx_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x39: /* AND aaaa,Y */
- A &= MegaGetMem (_eaabsy_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x21: /* AND (aa,X) */
- A &= MegaGetMem (_eaindx_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x31: /* AND (aa),Y */
- A &= MegaGetMem (_eaindy_ ());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- case 0x0a: /* ASL A */
- _setC_ (A >= 0x80);
- A = (A << 1) & 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x06: /* ASL aa */
- hi = _eazp_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x16: /* ASL aa,X */
- hi = _eazpx_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x0e: /* ASL aaaa */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x1e: /* ASL aaaa,X */
- hi = _eaabsx_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
-
-
- case 0x90: /* BCC rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (!_getC_) PPC += lo;
- break;
-
-
-
- case 0xb0: /* BCS rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (_getC_) PPC += lo;
- break;
-
-
-
- case 0xf0: /* BEQ rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (_getZ_) PPC += lo;
- break;
-
-
-
- case 0x24: /* BIT aa */
- d = MegaGetMem ((ADDR)_eazp_ ());
- _setN_ (d >= 0x80);
- _setV_ ((d & 64) != 0);
- _setZ_ ((d & A) == 0);
- break;
-
- case 0x2c: /* BIT aaaa */
- d = MegaGetMem (_eaabs_ ());
- _setN_ (d >= 0x80);
- _setV_ ((d & 64) != 0);
- _setZ_ ((d & A) == 0);
- break;
-
-
-
- case 0x30: /* BMI rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (_getN_) PPC += lo;
- break;
-
-
-
- case 0xd0: /* BNE rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (!_getZ_) PPC += lo;
- break;
-
-
-
- case 0x10: /* BPL rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (!_getN_) PPC += lo;
- break;
-
-
-
- case 0x00: /* BRK */
- lo = (PPC+1) & 65535;
- _push_ ((BYTE)(lo / 0x0100));
- _push_ ((BYTE)(lo % 0x0100));
- _push_ ((BYTE)P);
- _setB_ (1);
- lo = MegaGetMem (0xfffe);
- hi = MegaGetMem (0xffff);
- PPC = lo + (hi*0x0100);
- break;
-
-
-
- case 0x50: /* BVC rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (!_getV_) PPC += lo;
- break;
-
-
-
- case 0x70: /* BVS rr */
- lo = _eaimm_ ();
- if (lo >= 0x80) lo -= 0x0100;
- if (_getV_) PPC += lo;
- break;
-
-
-
- case 0x18: /* CLC */
- _setC_ (0);
- break;
-
-
-
- case 0xd8: /* CLD */
- _setD_ (0);
- break;
-
-
-
- case 0x58: /* CLI */
- _setI_ (0);
- break;
-
-
-
- case 0xb8: /* CLV */
- _setV_ (0);
- break;
-
-
-
- case 0xc9: /* CMP #dd */
- d = _eaimm_();
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xc5: /* CMP aa */
- d = MegaGetMem ((ADDR)_eazp_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xd5: /* CMP aa,X */
- d = MegaGetMem ((ADDR)_eazpx_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xcd: /* CMP aaaa */
- d = MegaGetMem (_eaabs_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xdd: /* CMP aaaa,X */
- d = MegaGetMem (_eaabsx_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xd9: /* CMP aaaa,Y */
- d = MegaGetMem (_eaabsy_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xc1: /* CMP (aa,X) */
- d = MegaGetMem (_eaindx_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xd1: /* CMP (aa),y */
- d = MegaGetMem (_eaindy_());
- _setZ_ (A == d);
- _setC_ (A >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = A;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
-
-
- case 0xe0: /* CPX #dd */
- d = _eaimm_();
- _setZ_ (X == d);
- _setC_ (X >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = X;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xe4: /* CPX aa */
- d = MegaGetMem ((ADDR)_eazp_());
- _setZ_ (X == d);
- _setC_ (X >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = X;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xec: /* CPX aaaa */
- d = MegaGetMem (_eaabs_());
- _setZ_ (X == d);
- _setC_ (X >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = X;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
-
-
- case 0xc0: /* CPY #dd */
- d = _eaimm_();
- _setZ_ (Y == d);
- _setC_ (Y >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = Y;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xc4: /* CPY aa */
- d = MegaGetMem ((ADDR)_eazp_());
- _setZ_ (Y == d);
- _setC_ (Y >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = Y;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
- case 0xcc: /* CPY aaaa */
- d = MegaGetMem (_eaabs_());
- _setZ_ (Y == d);
- _setC_ (Y >= d);
- if (d >= 0x80) d -= 0x0100;
- lo = Y;
- if (lo >= 0x80) lo -= 0x0100;
- hi = lo - d;
- _setN_ ( (hi >= 0x80) || (hi < 0) );
- if (hi < -0x80) _setN_(0);
- break;
-
-
-
- case 0xc6: /* DEC aa */
- hi = _eazp_();
- d = MegaGetMem ((ADDR)hi) - 1;
- if (d < 0) d += 0x0100;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0xd6: /* DEC aa,X */
- hi = _eazpx_();
- d = MegaGetMem ((ADDR)hi) - 1;
- if (d < 0) d += 0x0100;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0xce: /* DEC aaaa */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi) - 1;
- if (d < 0) d += 0x0100;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0xde: /* DEC aaaa,X */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi) - 1;
- if (d < 0) d += 0x0100;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
-
-
- case 0xca: /* DEX */
- X--;
- if (X < 0) X += 0x0100;
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
-
-
- case 0x88: /* DEY */
- Y--;
- if (Y < 0) Y += 0x0100;
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
-
-
- case 0x49: /* EOR #dd */
- d = _eaimm_();
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x45: /* EOR aa */
- d = MegaGetMem ((ADDR)_eazp_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x55: /* EOR aa,X */
- d = MegaGetMem ((ADDR)_eazpx_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x4d: /* EOR aaaa */
- d = MegaGetMem (_eaabs_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x5d: /* EOR aaaa,X */
- d = MegaGetMem (_eaabsx_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x59: /* EOR aaaa,Y */
- d = MegaGetMem (_eaabsy_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x41: /* EOR (aa,X) */
- d = MegaGetMem (_eaindx_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x51: /* EOR (aa),Y */
- d = MegaGetMem (_eaindy_());
- A ^= d; A &= 0xff;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- case 0xe6: /* INC aa */
- hi = _eazp_();
- d = MegaGetMem ((ADDR)hi) + 1;
- d &= 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0xf6: /* INC aa,X */
- hi = _eazpx_();
- d = MegaGetMem ((ADDR)hi) + 1;
- d &= 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0xee: /* INC aaaa */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi) + 1;
- d &= 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0xfe: /* INC aaaa,X */
- hi = _eaabsx_();
- d = MegaGetMem ((ADDR)hi) + 1;
- d &= 0xff;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
-
-
- case 0xe8: /* INX */
- X++;
- X &= 0xff;
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
-
-
- case 0xc8: /* INY */
- Y++;
- Y &= 0xff;
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
-
-
- case 0x4c: /* JMP aaaa */
- PPC = _eaabs_();
- break;
-
- case 0x6c: /* JMP (aaaa) */
- PPC = _eaabsind_();
- break;
-
-
-
- case 0x20: /* JSR aaaa */
- /* Push address of 3rd byte of jsr: */
- lo = (PPC+1) & 65535;
- _push_ ((BYTE)(lo / 0x0100));
- _push_ ((BYTE)(lo % 0x0100));
- PPC = _eaabs_();
- break;
-
-
-
- case 0xa9: /* LDA #dd */
- A = _eaimm_();
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xa5: /* LDA aa */
- A = MegaGetMem ((ADDR)_eazp_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xb5: /* LDA aa,X */
- A = MegaGetMem ((ADDR)_eazpx_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xad: /* LDA aaaa */
- A = MegaGetMem (_eaabs_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xbd: /* LDA aaaa,X */
- A = MegaGetMem (_eaabsx_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xb9: /* LDA aaaa,Y */
- A = MegaGetMem (_eaabsy_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xa1: /* LDA (aa,X) */
- A = MegaGetMem (_eaindx_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0xb1: /* LDA (aa),Y */
- A = MegaGetMem (_eaindy_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- case 0xa2: /* LDX #dd */
- X = _eaimm_();
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
- case 0xa6: /* LDX aa */
- X = MegaGetMem ((ADDR)_eazp_());
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
- case 0xb6: /* LDX aa,Y */
- X = MegaGetMem ((ADDR)_eazpy_());
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
- case 0xae: /* LDX aaaa */
- X = MegaGetMem (_eaabs_());
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
- case 0xbe: /* LDX aaaa,Y */
- X = MegaGetMem (_eaabsy_());
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
-
-
- case 0xa0: /* LDY #dd */
- Y = _eaimm_();
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
- case 0xa4: /* LDY aa */
- Y = MegaGetMem ((ADDR)_eazp_());
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
- case 0xb4: /* LDY aa,X */
- Y = MegaGetMem ((ADDR)_eazpx_());
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
- case 0xac: /* LDY aaaa */
- Y = MegaGetMem (_eaabs_());
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
- case 0xbc: /* LDY aaaa,X */
- Y = MegaGetMem (_eaabsx_());
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
-
-
- case 0x4a: /* LSR A */
- _setC_ (A & 1);
- A = A >> 1;
- _setN_ (0);
- _setZ_ (A == 0);
- break;
-
- case 0x46: /* LSR aa */
- hi = _eazp_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d & 1);
- d = d >> 1;
- _setN_ (0);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x56: /* LSR aa,X */
- hi = _eazpx_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d & 1);
- d = d >> 1;
- _setN_ (0);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x4e: /* LSR aaaa */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d & 1);
- d = d >> 1;
- _setN_ (0);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x5e: /* LSR aaaa,X */
- hi = _eaabsx_();
- d = MegaGetMem ((ADDR)hi);
- _setC_ (d & 1);
- d = d >> 1;
- _setN_ (0);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
-
-
- case 0xea: /* NOP */
-nop:
- break;
-
-
-
- case 0x09: /* ORA #dd */
- A |= _eaimm_();
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x05: /* ORA aa */
- A |= MegaGetMem ((ADDR)_eazp_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x15: /* ORA aa,X */
- A |= MegaGetMem ((ADDR)_eazpx_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x0d: /* ORA aaaa */
- A |= MegaGetMem (_eaabs_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x1d: /* ORA aaaa,X */
- A |= MegaGetMem (_eaabsx_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x19: /* ORA aaaa,Y */
- A |= MegaGetMem (_eaabsy_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x01: /* ORA (aa,X) */
- A |= MegaGetMem (_eaindx_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x11: /* ORA (aa),Y */
- A |= MegaGetMem (_eaindy_());
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- case 0x48: /* PHA */
- _push_ ((BYTE)A);
- break;
-
-
-
- case 0x08: /* PHP */
- _push_ ((BYTE)P);
- break;
-
-
-
- case 0x68: /* PLA */
- A = _pull_();
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- case 0x28: /* PLP */
- P = _pull_();
- break;
-
-
-
- case 0x2a: /* ROL A */
- al = _getC_;
- _setC_ (A >= 0x80);
- A = (A << 1) & 0xff;
- A |= al;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x26: /* ROL aa */
- hi = _eazp_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- d |= al;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x36: /* ROL aa,X */
- hi = _eazpx_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- d |= al;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x2e: /* ROL aaaa */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- d |= al;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x3e: /* ROL aaaa,X */
- hi = _eaabsx_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d >= 0x80);
- d = (d << 1) & 0xff;
- d |= al;
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
-
-
- case 0x6a: /* ROR A */
- al = _getC_;
- _setC_ (A & 1);
- A = A >> 1;
- A |= (al*0x80);
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
- case 0x66: /* ROR aa */
- hi = _eazp_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d & 1);
- d = d >> 1;
- d |= (al*0x80);
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x76: /* ROR aa,X */
- hi = _eazpx_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d & 1);
- d = d >> 1;
- d |= (al*0x80);
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x6e: /* ROR aaaa */
- hi = _eaabs_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d & 1);
- d = d >> 1;
- d |= (al*0x80);
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
- case 0x7e: /* ROR aaaa,X */
- hi = _eaabsx_();
- d = MegaGetMem ((ADDR)hi);
- al = _getC_;
- _setC_ (d & 1);
- d = d >> 1;
- d |= (al*0x80);
- _setN_ (d >= 0x80);
- _setZ_ (d == 0);
- MegaPutMem ((ADDR)hi,(BYTE)d);
- break;
-
-
-
- case 0x40: /* RTI */
- P = _pull_();
- lo = _pull_();
- hi = _pull_();
- PPC = lo + (hi*0x0100);
- break;
-
-
-
-
- case 0x60: /* RTS */
- lo = _pull_();
- hi = _pull_();
- PPC = 1 + lo + (hi*0x0100);
- break;
-
-
-
- case 0xe9: /* SBC #dd */
- d = _eaimm_ ();
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xe5: /* SBC aa */
- d = MegaGetMem ((ADDR)_eazp_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xf5: /* SBC aa,x */
- d = MegaGetMem ((ADDR)_eazpx_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xed: /* SBC aaaa */
- d = MegaGetMem (_eaabs_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xfd: /* SBC aaaa,X */
- d = MegaGetMem (_eaabsx_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xf9: /* SBC aaaa,Y */
- d = MegaGetMem (_eaabsy_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xe1: /* SBC (aa,X) */
- d = MegaGetMem (_eaindx_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
- case 0xf1: /* SBC (aa),Y */
- d = MegaGetMem (_eaindy_ ());
- if (!_getD_) {
- A -= d; A -= !_getC_;
- _setC_ (! (A < 0));
- } else {
- ah = A / 16; al = A % 16;
- oh = d / 16; ol = d % 16;
- al -= !_getC_; al -= ol;
- if (al < 0) { al += 10; ah--; }
- ah -= oh;
- _setC_ (! (ah < 0));
- if (ah < 0) ah += 10;
- A = al + (ah*16);
- }
- _setV_ ((A < -0x80) || (A > 0x7f));
- if (A < 0) A += 0x0100;
- A %= 0x0100;
- _setZ_ (A == 0);
- _setN_ (A >= 0x80);
- break;
-
-
-
- case 0x38: /* SEC */
- _setC_ (1);
- break;
-
-
-
- case 0xf8: /* SED */
- _setD_ (1);
- break;
-
-
-
- case 0x78: /* SEI */
- _setI_ (1);
- break;
-
-
-
- case 0x85: /* STA aa */
- hi = _eazp_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x95: /* STA aa,X */
- hi = _eazpx_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x8d: /* STA aaaa */
- hi = _eaabs_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x9d: /* STA aaaa,X */
- hi = _eaabsx_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x99: /* STA aaaa,Y */
- hi = _eaabsy_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x81: /* STA (aa,X) */
- hi = _eaindx_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x91: /* STA (aa),Y */
- hi = _eaindy_();
- MegaPutMem ((ADDR)hi,(BYTE)A);
- break;
-
-
-
- case 0x86: /* STX aa */
- hi = _eazp_();
- MegaPutMem ((ADDR)hi,(BYTE)X);
- break;
-
-
-
- case 0x96: /* STX aa,Y */
- hi = _eazpy_();
- MegaPutMem ((ADDR)hi,(BYTE)X);
- break;
-
-
-
- case 0x8e: /* STX aaaa */
- hi = _eaabs_();
- MegaPutMem ((ADDR)hi,(BYTE)X);
- break;
-
-
-
- case 0x84: /* STY aa */
- hi = _eazp_();
- MegaPutMem ((ADDR)hi,(BYTE)Y);
- break;
-
-
-
- case 0x94: /* STY aa,X */
- hi = _eazpx_();
- MegaPutMem ((ADDR)hi,(BYTE)Y);
- break;
-
-
-
- case 0x8c: /* STY aaaa */
- hi = _eaabs_();
- MegaPutMem ((ADDR)hi,(BYTE)Y);
- break;
-
-
-
- case 0xaa: /* TAX */
- X = A;
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
-
-
- case 0xa8: /* TAY */
- Y = A;
- _setN_ (Y >= 0x80);
- _setZ_ (Y == 0);
- break;
-
-
-
- case 0xba: /* TSX */
- X = S;
- _setN_ (X >= 0x80);
- _setZ_ (X == 0);
- break;
-
-
-
- case 0x8a: /* TXA */
- A = X;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- case 0x9a: /* TXS */
- S = X;
- break;
-
-
-
- case 0x98: /* TYA */
- A = Y;
- _setN_ (A >= 0x80);
- _setZ_ (A == 0);
- break;
-
-
-
- default: /* Undefined opcode */
- goto nop;
- break;
- }
-}
-
-
+ END OF ARCHIVE