]> Shamusworld >> Repos - stargem2/blobdiff - src/v6809.cpp
Finalizing move to trunk...
[stargem2] / src / v6809.cpp
index 494b9f11abf117e749b37ab0c8204882fa5918f8..648d02b8d2f15ee5632cb545edc1c0e762add828 100755 (executable)
 // ---  ----------  ------------------------------------------------------------
 // JLH  06/15/2006  Added changelog ;-)
 // JLH  06/15/2006  Scrubbed all BYTE, WORD & DWORD references from the code
+// JLH  11/11/2006  Removed all SignedX() references
 //
 
 // Mebbe someday I'll get around to fixing the core to be more like V65C02...
+// We have a start... ;-)
 //
 
+#define __DEBUG__
+
 #include "v6809.h"
 
 #ifdef __DEBUG__
 #include "log.h"               // Temporary...
 #endif
 
+// Various macros
+
+#define CLR_Z                          (regs.cc &= ~FLAG_Z)
+#define CLR_ZN                         (regs.cc &= ~(FLAG_Z | FLAG_N))
+#define CLR_ZNC                                (regs.cc &= ~(FLAG_Z | FLAG_N | FLAG_C))
+#define CLR_V                          (regs.cc &= ~FLAG_V)
+#define CLR_N                          (regs.cc &= ~FLAG_N)
+#define SET_Z(r)                       (regs.cc = ((r) == 0 ? regs.cc | FLAG_Z : regs.cc & ~FLAG_Z))
+#define SET_N(r)                       (regs.cc = ((r) & 0x80 ? regs.cc | FLAG_N : regs.cc & ~FLAG_N))
+
+//Not sure that this code is computing the carry correctly... Investigate! [Seems to be]
+#define SET_C_ADD(a,b)         (regs.cc = ((uint8)(b) > (uint8)(~(a)) ? regs.cc | FLAG_C : regs.cc & ~FLAG_C))
+//#define SET_C_SUB(a,b)               (regs.cc = ((uint8)(b) >= (uint8)(a) ? regs.cc | FLAG_C : regs.cc & ~FLAG_C))
+#define SET_C_CMP(a,b)         (regs.cc = ((uint8)(b) >= (uint8)(a) ? regs.cc | FLAG_C : regs.cc & ~FLAG_C))
+#define SET_ZN(r)                      SET_N(r); SET_Z(r)
+#define SET_ZNC_ADD(a,b,r)     SET_N(r); SET_Z(r); SET_C_ADD(a,b)
+//#define SET_ZNC_SUB(a,b,r)   SET_N(r); SET_Z(r); SET_C_SUB(a,b)
+#define SET_ZNC_CMP(a,b,r)     SET_N(r); SET_Z(r); SET_C_CMP(a,b)
+
+//Small problem with the EA_ macros: ABS macros don't increment the PC!!! !!! FIX !!!
+#define EA_IMM                         regs.pc++
+#define EA_ZP                          regs.RdMem(regs.pc++)
+#define EA_ZP_X                                (regs.RdMem(regs.pc++) + regs.x) & 0xFF
+#define EA_ZP_Y                                (regs.RdMem(regs.pc++) + regs.y) & 0xFF
+#define EA_ABS                         RdMemW(regs.pc)
+#define EA_ABS_X                       RdMemW(regs.pc) + regs.x
+#define EA_ABS_Y                       RdMemW(regs.pc) + regs.y
+#define EA_IND_ZP_X                    RdMemW((regs.RdMem(regs.pc++) + regs.x) & 0xFF)
+#define EA_IND_ZP_Y                    RdMemW(regs.RdMem(regs.pc++)) + regs.y
+#define EA_IND_ZP                      RdMemW(regs.RdMem(regs.pc++))
+
+#define READ_IMM                       regs.RdMem(EA_IMM)
+#define READ_ZP                                regs.RdMem(EA_ZP)
+#define READ_ZP_X                      regs.RdMem(EA_ZP_X)
+#define READ_ZP_Y                      regs.RdMem(EA_ZP_Y)
+#define READ_ABS                       regs.RdMem(EA_ABS);     regs.pc += 2
+#define READ_ABS_X                     regs.RdMem(EA_ABS_X);   regs.pc += 2
+#define READ_ABS_Y                     regs.RdMem(EA_ABS_Y);   regs.pc += 2
+#define READ_IND_ZP_X          regs.RdMem(EA_IND_ZP_X)
+#define READ_IND_ZP_Y          regs.RdMem(EA_IND_ZP_Y)
+#define READ_IND_ZP                    regs.RdMem(EA_IND_ZP)
+
+#define READ_IMM_WB(v)         uint16 addr = EA_IMM;      v = regs.RdMem(addr)
+#define READ_ZP_WB(v)          uint16 addr = EA_ZP;       v = regs.RdMem(addr)
+#define READ_ZP_X_WB(v)                uint16 addr = EA_ZP_X;     v = regs.RdMem(addr)
+#define READ_ABS_WB(v)         uint16 addr = EA_ABS;      v = regs.RdMem(addr); regs.pc += 2
+#define READ_ABS_X_WB(v)       uint16 addr = EA_ABS_X;    v = regs.RdMem(addr); regs.pc += 2
+#define READ_ABS_Y_WB(v)       uint16 addr = EA_ABS_Y;    v = regs.RdMem(addr); regs.pc += 2
+#define READ_IND_ZP_X_WB(v)    uint16 addr = EA_IND_ZP_X; v = regs.RdMem(addr)
+#define READ_IND_ZP_Y_WB(v)    uint16 addr = EA_IND_ZP_Y; v = regs.RdMem(addr)
+#define READ_IND_ZP_WB(v)      uint16 addr = EA_IND_ZP;   v = regs.RdMem(addr)
+
+#define WRITE_BACK(d)          regs.WrMem(addr, (d))
+
 // Private global variables
 
 static V6809REGS regs;
+//Let's see if we can nuke this shit.
 static uint16 addr;                                                            // Temporary variables common to all funcs...
 static uint8 tmp;
 
 // Private function prototypes
 
-static int SignedB(uint8);                                             // Return signed byte from unsigned
-static int SignedW(uint16);                                            // Return signed word from unsigned
 static uint16 FetchW(void);
 static uint16 RdMemW(uint16 addr);
 static void WrMemW(uint16 addr, uint16 w);
@@ -186,22 +243,6 @@ void WrMemW(uint16 addr, uint16 w)
        regs.WrMem(addr + 1, w & 0xFF);
 }
 
-//
-// return signed byte from unsigned
-//
-int SignedB(uint8 b)
-{
-       return (b & 0x80 ? b - 256 : b);
-}
-
-//
-// return signed word from unsigned
-//
-int SignedW(uint16 w)
-{
-       return (w & 0x8000 ? w - 65536 : w);
-}
-
 //
 // Function to read TFR/EXG post byte
 //
@@ -343,31 +384,38 @@ uint16 DecodeIDX(uint8 code)
                                addr = RdMemW(woff);
                                break;
                        case 5:
-                               woff = DecodeReg(reg) + SignedB(regs.b);
+//                             woff = DecodeReg(reg) + SignedB(regs.b);
+                               woff = DecodeReg(reg) + (int16)(int8)regs.b;
                                addr = RdMemW(woff);
                                break;
                        case 6:
-                               woff = DecodeReg(reg) + SignedB(regs.a);
+//                             woff = DecodeReg(reg) + SignedB(regs.a);
+                               woff = DecodeReg(reg) + (int16)(int8)regs.a;
                                addr = RdMemW(woff);
                                break;
                        case 8:
-                               woff = DecodeReg(reg) + SignedB(regs.RdMem(regs.pc++));
+//                             woff = DecodeReg(reg) + SignedB(regs.RdMem(regs.pc++));
+                               woff = DecodeReg(reg) + (int16)(int8)regs.RdMem(regs.pc++);
                                addr = RdMemW(woff);
                                break;
                        case 9:
-                               woff = DecodeReg(reg) + SignedW(FetchW());
+//                             woff = DecodeReg(reg) + SignedW(FetchW());
+                               woff = DecodeReg(reg) + FetchW();
                                addr = RdMemW(woff);
                                break;
                        case 11:
-                               woff = DecodeReg(reg) + SignedW((regs.a << 8) | regs.b);
+//                             woff = DecodeReg(reg) + SignedW((regs.a << 8) | regs.b);
+                               woff = DecodeReg(reg) + ((regs.a << 8) | regs.b);
                                addr = RdMemW(woff);
                                break;
                        case 12:
-                               woff = regs.pc + SignedB(regs.RdMem(regs.pc++));
+//                             woff = regs.pc + SignedB(regs.RdMem(regs.pc++));
+                               woff = regs.pc + (int16)(int8)regs.RdMem(regs.pc++);
                                addr = RdMemW(woff);
                                break;
                        case 13:
-                               woff = regs.pc + SignedW(FetchW());
+//                             woff = regs.pc + SignedW(FetchW());
+                               woff = regs.pc + FetchW();
                                addr = RdMemW(woff);
                                break;
                        case 15:
@@ -417,13 +465,20 @@ uint16 DecodeIDX(uint8 code)
                    }
                    addr = DecodeReg(reg);  break; }
         case 4:  { addr = DecodeReg(reg);  break; }
-        case 5:  { addr = DecodeReg(reg) + SignedB(regs.b);  break; }
-        case 6:  { addr = DecodeReg(reg) + SignedB(regs.a);  break; }
-        case 8:  { addr = DecodeReg(reg) + SignedB(regs.RdMem(regs.pc++));  break; }
-        case 9:  { addr = DecodeReg(reg) + SignedW(FetchW());  break; }
-        case 11: { addr = DecodeReg(reg) + SignedW((regs.a << 8) | regs.b);  break; }
-        case 12: { addr = regs.pc + SignedB(regs.RdMem(regs.pc++));  break; }
-        case 13: { addr = regs.pc + SignedW(FetchW());  break; }
+//        case 5:  { addr = DecodeReg(reg) + SignedB(regs.b);  break; }
+        case 5:  { addr = DecodeReg(reg) + (int16)(int8)regs.b;  break; }
+//        case 6:  { addr = DecodeReg(reg) + SignedB(regs.a);  break; }
+        case 6:  { addr = DecodeReg(reg) + (int16)(int8)regs.a;  break; }
+//        case 8:  { addr = DecodeReg(reg) + SignedB(regs.RdMem(regs.pc++));  break; }
+        case 8:  { addr = DecodeReg(reg) + (int16)(int8)regs.RdMem(regs.pc++);  break; }
+//        case 9:  { addr = DecodeReg(reg) + SignedW(FetchW());  break; }
+        case 9:  { addr = DecodeReg(reg) + FetchW();  break; }
+//        case 11: { addr = DecodeReg(reg) + SignedW((regs.a << 8) | regs.b);  break; }
+        case 11: { addr = DecodeReg(reg) + ((regs.a << 8) | regs.b);  break; }
+//        case 12: { addr = regs.pc + SignedB(regs.RdMem(regs.pc++));  break; }
+        case 12: { addr = regs.pc + (int16)(int8)regs.RdMem(regs.pc++);  break; }
+//        case 13: { addr = regs.pc + SignedW(FetchW());  break; }
+        case 13: { addr = regs.pc + FetchW();  break; }
                        }
                }
        }
@@ -565,32 +620,41 @@ static void Op10(void)                                                                                    // Page 1 opcode
        exec_op1[regs.RdMem(regs.pc++)]();
 }
 
-static void Op11(void)                                                                                 // Page 2 opcode
+static void Op11(void)                                                 // Page 2 opcode
 {
        exec_op2[regs.RdMem(regs.pc++)]();
 }
 
-static void Op12(void)                                                                                 // NOP
+static void Op12(void)                                                 // NOP
 {
        regs.clock += 2;
 }
 
-static void Op13(void)  // SYNC
-{ 
-  regs.clock += 2;
+static void Op13(void)                                                 // SYNC
+{
+       // Fix this so it does the right thing (software interrupt!)
+       regs.clock += 2;
 }
-static void Op16(void)  // LBRA
+
+static void Op16(void)                                                 // LBRA
 {
-  regs.pc += SignedW(FetchW());
-  regs.clock += 5;
+//     regs.pc += SignedW(FetchW());
+       regs.pc += FetchW();                                            // No need to make signed, both are 16 bit quantities
+
+       regs.clock += 5;
 }
-static void Op17(void)  // LBSR
+
+static void Op17(void)                                                 // LBSR
 {
-  addr = FetchW();
-  regs.WrMem(--regs.s, regs.pc&0xFF);  regs.WrMem(--regs.s, regs.pc>>8);
-  regs.pc += SignedW(addr);
-  regs.clock += 9;
+       uint16 word = FetchW();
+       regs.WrMem(--regs.s, regs.pc & 0xFF);
+       regs.WrMem(--regs.s, regs.pc >> 8);
+//     regs.pc += SignedW(addr);
+       regs.pc += word;                                                        // No need to make signed, both are 16 bit
+
+       regs.clock += 9;
 }
+
 static void Op19(void)  // DAA
 {
   if ((regs.cc&0x20) || ((regs.a&0x0F) > 0x09))    // H set or lo nyb too big?
@@ -621,7 +685,7 @@ static void Op1C(void)                                                                      // ANDCC #
        regs.clock += 3;
 }
 
-static void Op1D(void)                                                                 // SEX
+static void Op1D(void)                                                 // SEX
 {
        (regs.b & 0x80 ? regs.a = 0xFF : regs.a = 0x00);
 
@@ -631,7 +695,7 @@ static void Op1D(void)                                                                      // SEX
        regs.clock += 2;
 }
 
-static void Op1E(void)                                                                 // EXG
+static void Op1E(void)                                                 // EXG
 {
        tmp = regs.RdMem(regs.pc++);
        addr = ReadEXG(tmp >> 4);
@@ -647,100 +711,162 @@ static void Op1F(void)  // TFR
   WriteEXG(tmp&0xF, ReadEXG(tmp>>4));
   regs.clock += 7;
 }
-static void Op20(void)  // BRA
+
+static void Op20(void)                                                 // BRA
 {
-  regs.pc += SignedB(regs.RdMem(regs.pc++));  // Branch always
-  regs.clock += 3;
+//     regs.pc += SignedB(regs.RdMem(regs.pc++));  // Branch always
+       regs.pc += (int16)(int8)regs.RdMem(regs.pc) + 1;        // Branch always
+
+       regs.clock += 3;
 }
-static void Op21(void)  // BRN
+
+static void Op21(void)                                                 // BRN
 {
-  regs.RdMem(regs.pc++);
-  regs.clock += 3;
+       regs.RdMem(regs.pc++);
+
+       regs.clock += 3;
 }
-static void Op22(void)  // BHI
+
+static void Op22(void)                                                 // BHI
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!(regs.cc&0x05))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!(regs.cc & 0x05))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op23(void)  // BLS
+
+static void Op23(void)                                                 // BLS
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (regs.cc&0x05)  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (regs.cc & 0x05)
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op24(void)  // BCC (BHS)
+
+static void Op24(void)                                                 // BCC (BHS)
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!(regs.cc&0x01))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!(regs.cc & 0x01))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op25(void)  // BCS (BLO)
+
+static void Op25(void)                                                 // BCS (BLO)
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (regs.cc&0x01)  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (regs.cc & 0x01)
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op26(void)  // BNE
+
+static void Op26(void)                                                 // BNE
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!(regs.cc&0x04))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!(regs.cc & 0x04))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op27(void)  // BEQ
+
+static void Op27(void)                                                 // BEQ
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (regs.cc&0x04)  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (regs.cc & 0x04)
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op28(void)  // BVC
+
+static void Op28(void)                                                 // BVC
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!(regs.cc&0x02))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!(regs.cc & 0x02))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op29(void)  // BVS
+
+static void Op29(void)                                                 // BVS
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (regs.cc&0x02)  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (regs.cc & 0x02)
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op2A(void)  // BPL
+
+static void Op2A(void)                                                 // BPL
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!(regs.cc&0x08))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!(regs.cc & 0x08))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op2B(void)  // BMI
+
+static void Op2B(void)                                                 // BMI
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (regs.cc&0x08)  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (regs.cc & 0x08)
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op2C(void)  // BGE
+
+static void Op2C(void)                                                 // BGE
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!(((regs.cc&0x08) >> 2) ^ (regs.cc&0x02)))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!(((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02)))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op2D(void)  // BLT
+
+static void Op2D(void)                                                 // BLT
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (((regs.cc&0x08) >> 2) ^ (regs.cc&0x02))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op2E(void)  // BGT
+
+static void Op2E(void)                                                 // BGT
 {
-  tmp = regs.RdMem(regs.pc++);
-  if (!((regs.cc&0x04) | (((regs.cc&0x08) >> 2) ^ (regs.cc&0x02))))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if (!((regs.cc & 0x04) | (((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02))))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
-static void Op2F(void)  // BLE
+
+static void Op2F(void)                                                 // BLE
 {
-  tmp = regs.RdMem(regs.pc++);
-  if ((regs.cc&0x04) | (((regs.cc&0x08) >> 2) ^ (regs.cc&0x02)))  regs.pc += SignedB(tmp);
-  regs.clock += 3;
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+
+       if ((regs.cc & 0x04) | (((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02)))
+               regs.pc += word;
+
+       regs.clock += 3;
 }
+
 static void Op30(void)  // LEAX
 {
   regs.x = DecodeIDX(regs.RdMem(regs.pc++));
@@ -1394,13 +1520,17 @@ static void Op8C(void)  // CMPX #
         (dw&0x8000 ? regs.cc |= 0x08 : regs.cc &= 0xF7);  // Adjust Negative flag
         regs.clock += 4;
 }
-static void Op8D(void)  // Bregs.s
-      {
-        tmp = regs.RdMem(regs.pc++);
-        regs.WrMem(--regs.s, regs.pc&0xFF);  regs.WrMem(--regs.s, regs.pc>>8);
-        regs.pc += SignedB(tmp);
-        regs.clock += 7;
-      }
+
+static void Op8D(void)                                                 // Bregs.s
+{
+       uint16 word = (int16)(int8)regs.RdMem(regs.pc++);
+       regs.WrMem(--regs.s, regs.pc & 0xFF);
+       regs.WrMem(--regs.s, regs.pc >> 8);
+       regs.pc += word;
+
+       regs.clock += 7;
+}
+
 static void Op8E(void)  // LDX #
       {
         regs.x = FetchW();
@@ -2445,95 +2575,153 @@ static void OpFF(void)  // STU ABS
 // Page one opcodes' execute code
 //
 
-static void Op1021(void)  // LBRN
+static void Op1021(void)                                               // LBRN
 {
-  addr = FetchW();
-  regs.clock += 5;
+       addr = FetchW();
+
+       regs.clock += 5;
 }
-static void Op1022(void)  // LBHI
+
+static void Op1022(void)                                               // LBHI
 {
-  addr = FetchW();
-  if (!((regs.cc&0x01)|(regs.cc&0x04)))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!((regs.cc & 0x01) | (regs.cc & 0x04)))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1023(void)  // LBLS
+
+static void Op1023(void)                                               // LBLS
 {
-  addr = FetchW();
-  if ((regs.cc&0x01)|(regs.cc&0x04))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if ((regs.cc & 0x01) | (regs.cc & 0x04))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1024(void)  // LBCC (LBHS)
+
+static void Op1024(void)                                               // LBCC (LBHS)
 {
-  addr = FetchW();
-  if (!(regs.cc&0x01))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!(regs.cc & 0x01))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1025(void)  // LBCS (LBLO)
+
+static void Op1025(void)                                               // LBCS (LBLO)
 {
-  addr = FetchW();
-  if (regs.cc&0x01)  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (regs.cc & 0x01)
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1026(void)  // LBNE
+
+static void Op1026(void)                                               // LBNE
 {
-  addr = FetchW();
-  if (!(regs.cc&0x04))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!(regs.cc & 0x04))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1027(void)  // LBEQ
+
+static void Op1027(void)                                               // LBEQ
 {
-  addr = FetchW();
-  if (regs.cc&0x04)  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (regs.cc & 0x04)
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1028(void)  // LBVC
+
+static void Op1028(void)                                               // LBVC
 {
-  addr = FetchW();
-  if (!(regs.cc&0x02))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!(regs.cc & 0x02))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op1029(void)  // LBVS
+
+static void Op1029(void)                                               // LBVS
 {
-  addr = FetchW();
-  if (regs.cc&0x02)  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (regs.cc & 0x02)
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op102A(void)  // LBPL
+
+static void Op102A(void)                                               // LBPL
 {
-  addr = FetchW();
-  if (!(regs.cc&0x08))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!(regs.cc & 0x08))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op102B(void)  // LBMI
+
+static void Op102B(void)                                               // LBMI
 {
-  addr = FetchW();
-  if (regs.cc&0x08)  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (regs.cc & 0x08)
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op102C(void)  // LBGE
+
+static void Op102C(void)                                               // LBGE
 {
-  addr = FetchW();
-  if (!(((regs.cc&0x08) >> 2) ^ (regs.cc&0x02)))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!(((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02)))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op102D(void)  // LBLT
+
+static void Op102D(void)                                               // LBLT
 {
-  addr = FetchW();
-  if (((regs.cc&0x08) >> 2) ^ (regs.cc&0x02))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op102E(void)  // LBGT
+
+static void Op102E(void)                                               // LBGT
 {
-  addr = FetchW();
-  if (!((regs.cc&0x04) | (((regs.cc&0x08) >> 2) ^ (regs.cc&0x02))))  regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if (!((regs.cc & 0x04) | (((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02))))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
-static void Op102F(void)  // LBLE
+
+static void Op102F(void)                                               // LBLE
 {
-  addr = FetchW();
-  if ((regs.cc&0x04) | (((regs.cc&0x08) >> 2) ^ (regs.cc&0x02))) regs.pc += SignedW(addr);
-  regs.clock += 5;
+       uint16 word = FetchW();
+
+       if ((regs.cc & 0x04) | (((regs.cc & 0x08) >> 2) ^ (regs.cc & 0x02)))
+               regs.pc += word;
+
+       regs.clock += 5;
 }
+
 static void Op103F(void)  // SWI2 (Not yet implemented)
 {
   regs.clock += 20;
@@ -2846,20 +3034,24 @@ static void Op11BC(void)  // CMPS ABS
 }
 
 //temp, for testing...
-/*static uint8 backTrace[256];
+#ifdef __DEBUG__
+static uint8 backTrace[256];
 static uint16 btPC[256];
 static int btPtr = 0;//*/
+#endif
 static void Op__(void)                                                                 // Illegal opcode
 {
        regs.clock++;
 //     illegal = true;
        regs.cpuFlags |= V6809_STATE_ILLEGAL_INST;
+#ifdef __DEBUG__
 /*WriteLog("V6809: Executed illegal opcode %02X at PC=%04X...\n\nBacktrace:\n\n", regs.RdMem(regs.pc - 1), regs.pc - 1);
 for(int i=0; i<256; i++)
 {
-       dpc = btPC[(btPtr+i)&0xFF];
-       Decode_6809();
+       Decode6809(btPC[(btPtr + i) & 0xFF]);
+       WriteLog("\n");
 }//*/
+#endif
 }
 
 
@@ -2884,15 +3076,20 @@ void Execute6809(V6809REGS * context, uint32 cycles)
        // Execute here...
        while (regs.clock < cycles)
        {
-/*static bool disasm = false;
-if (regs.pc == 0x15BA) disasm = true;
-if (disasm) { dpc = regs.pc; Decode_6809(); }
-if (regs.pc == 0x164A) disasm = false;//*/
+#ifdef __DEBUG__
+//Decode6809(regs.pc);
+static bool disasm = false;
+/*//if (regs.pc == 0x15BA)     disasm = true;
+//if (regs.pc == 0xFE76)       disasm = true;
+if (regs.x == 0xFED4)  disasm = true;
+if (disasm) Decode6809(regs.pc);
+//if (regs.pc == 0x164A)       disasm = false;//*/
 
 //temp, for testing...
 /*backTrace[btPtr] = regs.RdMem(regs.pc);
 btPC[btPtr] = regs.pc;
-btPtr = (btPtr++) & 0xFF;//*/
+btPtr = (btPtr + 1) & 0xFF;//*/
+#endif
                exec_op0[regs.RdMem(regs.pc++)]();
 
                // Handle any pending interrupts
@@ -2901,6 +3098,9 @@ btPtr = (btPtr++) & 0xFF;//*/
 
                if (flags & V6809_ASSERT_LINE_RESET)                    // *** RESET handler ***
                {
+#ifdef __DEBUG__
+if (disasm) WriteLog("\nV6809: RESET line asserted!\n");
+#endif
                        regs.cc |= (FLAG_F | FLAG_I);                           // Set F, I
                        regs.dp = 0;                                                            // Reset direct page register
                        regs.pc = RdMemW(0xFFFE);                                       // And load PC with the RESET vector
@@ -2909,6 +3109,9 @@ btPtr = (btPtr++) & 0xFF;//*/
                }
                else if (flags & V6809_ASSERT_LINE_NMI)                 // *** NMI handler ***
                {
+#ifdef __DEBUG__
+if (disasm) WriteLog("\nV6809: NMI line asserted!\n");
+#endif
                        regs.cc |= FLAG_E;                                                      // Set the Entire flag
 
                        regs.WrMem(--regs.s, regs.pc & 0xFF);           // Save all regs...
@@ -2932,8 +3135,14 @@ btPtr = (btPtr++) & 0xFF;//*/
                }
                else if (flags & V6809_ASSERT_LINE_FIRQ)                // *** FIRQ handler ***
                {
+#ifdef __DEBUG__
+if (disasm) WriteLog("\nV6809: FIRQ line asserted!\n");
+#endif
                        if (!(regs.cc & FLAG_F))                                        // Is the FIRQ masked (F == 1)?
                        {
+#ifdef __DEBUG__
+if (disasm) WriteLog("       FIRQ taken...\n");
+#endif
                                regs.cc &= ~FLAG_E;                                             // Clear the Entire flag
 
                                regs.WrMem(--regs.s, regs.pc & 0xFF);   // Save PC, CC regs...
@@ -2949,8 +3158,14 @@ btPtr = (btPtr++) & 0xFF;//*/
                }
                else if (flags & V6809_ASSERT_LINE_IRQ)                 // *** IRQ handler ***
                {
+#ifdef __DEBUG__
+if (disasm) WriteLog("\nV6809: IRQ line asserted!\n");
+#endif
                        if (!(regs.cc & FLAG_I))                                        // Is the IRQ masked (I == 1)?
                        {
+#ifdef __DEBUG__
+if (disasm) WriteLog("       IRQ taken...\n");
+#endif
                                regs.cc |= FLAG_E;                                              // Set the Entire flag
 
                                regs.WrMem(--regs.s, regs.pc & 0xFF);   // Save all regs...
@@ -2973,8 +3188,12 @@ btPtr = (btPtr++) & 0xFF;//*/
                                regs.cpuFlags &= ~V6809_ASSERT_LINE_IRQ;        // Reset the asserted line (IRQ)...
                        }
                }
-/*if (disasm) WriteLog("\tA=%02X B=%02X CC=%02X DP=%02X X=%04X Y=%04X S=%04X U=%04X PC=%04X\n",
+#ifdef __DEBUG__
+if (disasm) WriteLog("\tA=%02X B=%02X CC=%02X DP=%02X X=%04X Y=%04X S=%04X U=%04X PC=%04X\n",
+       regs.a, regs.b, regs.cc, regs.dp, regs.x, regs.y, regs.s, regs.u, regs.pc);//*/
+/*WriteLog("\tA=%02X B=%02X CC=%02X DP=%02X X=%04X Y=%04X S=%04X U=%04X PC=%04X\n",
        regs.a, regs.b, regs.cc, regs.dp, regs.x, regs.y, regs.s, regs.u, regs.pc);//*/
+#endif
        }
 
        myMemcpy(context, &regs, sizeof(V6809REGS));