diff --git a/src/main/java/dk/camelot64/cpufamily6502/CpuAddressingMode.java b/src/main/java/dk/camelot64/cpufamily6502/CpuAddressingMode.java
index b221e8aca..f602f8dc0 100644
--- a/src/main/java/dk/camelot64/cpufamily6502/CpuAddressingMode.java
+++ b/src/main/java/dk/camelot64/cpufamily6502/CpuAddressingMode.java
@@ -10,14 +10,14 @@ public enum CpuAddressingMode {
     * ACCUMULATOR ADDRESSING — This form of addressing is represented with a one byte instruction, implying an operation
     * on the accumulator"
     */
-   NON("", "%i", 1),
+   NON("", "%i", 0),
 
    /**
     * #imm Immediate <br>
     * IMMEDIATE ADDRESSING — In immediate addressing, the operand is contained in the second byte of the instruction,
     * with no further memory addressing required.
     */
-   IMM("#imm", "%i #%p", 2),
+   IMM("#imm", "%i #%p", 1),
 
    /**
     * zp Zeropage <br>
@@ -25,7 +25,7 @@ public enum CpuAddressingMode {
     * second byte of the instruction and assuming a zero high address byte. Careful use of the zero page can result in
     * significant increase in code efficiency.
     */
-   ZP("zp", "%i.z %p", 2),
+   ZP("zp", "%i.z %p", 1),
 
    /**
     * zp,x X Indexed Zeropage <br>
@@ -35,7 +35,7 @@ public enum CpuAddressingMode {
     * the second byte references a location in page zero. Additionally, due to the “Zero Page" addressing nature of this
     * mode, no carry is added to the high order 8 bits of memory and crossing of page boundaries does not occur.
     */
-   ZPX("zp,x", "%i.z %p,x", 2),
+   ZPX("zp,x", "%i.z %p,x", 1),
 
    /**
     * zp,y Y Indexed Zeropage <br>
@@ -45,7 +45,7 @@ public enum CpuAddressingMode {
     * of the second byte references a location in page zero. Additionally, due to the “Zero Page" addressing nature of
     * this mode, no carry is added to the high order 8 bits of memory and crossing of page boundaries does not occur.
     */
-   ZPY("zp,y", "%i.z %p,y", 2),
+   ZPY("zp,y", "%i.z %p,y", 1),
 
    /**
     * abs Absolute <br>
@@ -53,7 +53,7 @@ public enum CpuAddressingMode {
     * bits of the effective address while the third byte specifies the eight high order bits. Thus, the absolute
     * addressing mode allows access to the entire 65 K bytes of addressable memory.
     */
-   ABS("abs", "%i %p", 3),
+   ABS("abs", "%i %p", 2),
 
    /**
     * abs,x Absolute X <br>
@@ -64,7 +64,7 @@ public enum CpuAddressingMode {
     * of indexing allows any location referencing and the index to modify multiple fields resulting in reduced coding
     * and execution time.
     */
-   ABX("abs,x", "%i %p,x", 3),
+   ABX("abs,x", "%i %p,x", 2),
 
    /**
     * abs,y Absolute Y <br>
@@ -75,7 +75,7 @@ public enum CpuAddressingMode {
     * indexing allows any location referencing and the index to modify multiple fields resulting in reduced coding and
     * execution time.
     */
-   ABY("abs,y", "%i %p,y", 4),
+   ABY("abs,y", "%i %p,y", 2),
 
    /**
     * (zp,x) Indirect Zeropage X <br>
@@ -86,7 +86,7 @@ public enum CpuAddressingMode {
     * location in page zero contains the high order eight bits of the effective address. Both memory locations
     * specifying the high and low order bytes of the effective address must be in page zero."
     */
-   IZX("(zp,x)", "%i (%p,x)", 2),
+   IZX("(zp,x)", "%i (%p,x)", 1),
 
    /**
     * (abs,x) Indirect Absolute X <br>
@@ -95,7 +95,7 @@ public enum CpuAddressingMode {
     * the instruction to form an address to a pointer. This address mode is only used with the JMP/JSR instruction and the
     * program Counter is loaded with the first and second bytes at this pointer."
     */
-   IAX("(abs,x)", "%i (%p,x)", 3),
+   IAX("(abs,x)", "%i (%p,x)", 2),
 
    /**
     * (zp),y Indirect Zeropage Y
@@ -105,7 +105,7 @@ public enum CpuAddressingMode {
     * address. The carry from this addition is added to the contents of the next page zero memory location, the result
     * being the high order eight bits of the effective address."
     */
-   IZY("(zp),y", "%i (%p),y", 2),
+   IZY("(zp),y", "%i (%p),y", 1),
 
    /**
     * (zp),z Indirect Zeropage Z <br>
@@ -115,7 +115,7 @@ public enum CpuAddressingMode {
     * address. The carry from this addition is added to the contents of the next page zero memory location, the result
     * being the high order eight bits of the effective address."
     */
-   IZZ("(zp),z", "%i.z (%p),z", 2),
+   IZZ("(zp),z", "%i.z (%p),z", 1),
 
    /**
     * (abs) Indirect Absolute <br>
@@ -125,14 +125,14 @@ public enum CpuAddressingMode {
     * The next memory location contains the high order byte of the effective address which is loaded into the sixteen
     * bits of the program counter.
     */
-   IND("(abs)", "%i (%p)", 3),
+   IND("(abs)", "%i (%p)", 2),
 
    /**
     * (zp) Indirect Zeropage <br>
     * ZEROPAGE INDIRECT
     * The second byte of the instruction contains address of a zeropage memory location.
     */
-   INZ("(zp)", "%i.z (%p)", 2),
+   INZ("(zp)", "%i.z (%p)", 1),
 
    /**
     * ((zp)) 32-bit Indirect Zeropage <br>
@@ -140,7 +140,7 @@ public enum CpuAddressingMode {
     * In indirect addressing the second byte of the instruction points to a memory location in page zero. This mode is
     * formed by preceding a Base Page Indirect Mode instruction with NEG NEG NOP instructions.
     */
-   LIN("((zp))", "%i.z ((%p))", 2),
+   LIN("((zp))", "%i.z ((%p))", 1),
 
    /**
     * ((zp)),z 32-bit Indirect Zeropage Z <br>
@@ -148,7 +148,7 @@ public enum CpuAddressingMode {
     * In indirect indexed addressing the second byte of the instruction points to a memory location in page zero. This
     * mode is formed by preceding a Base Page Indirect Z-Indexed Mode instruction with the NOP instruction (opcode $EA).
     */
-   LIZ("((zp)),z", "%i.z ((%p)),z", 2),
+   LIZ("((zp)),z", "%i.z ((%p)),z", 1),
 
    /**
     * (zp,sp),y Stack Pointer Indirect Indexed <br>
@@ -159,7 +159,7 @@ public enum CpuAddressingMode {
     * addition is added to the contents of the next (D -1) stack location the result being the high order eight bits of
     * the effective address."	STA ($12,SP),Y
     */
-   ISY("(zp,sp),y", "%i.z (%p,sp),y", 2),
+   ISY("(zp,sp),y", "%i.z (%p,sp),y", 1),
 
    /**
     * Relative <br>
@@ -168,7 +168,7 @@ public enum CpuAddressingMode {
     * contents of the lower eight bits of the program counter when the counter is set at the next instruction. The range
     * of the offset is — 128 to + 127 bytes from the next instruction."
     */
-   REL("rel", "%i %p", 2),
+   REL("rel", "%i %p", 1),
 
    /**
     * zp,rel Zeropage Test Relative
@@ -176,7 +176,7 @@ public enum CpuAddressingMode {
     * test, and one indicating the signed relative PC offset if the branch is taken. This makes BBRi and BBSi the single
     * instructions with two explicit operands.
     */
-   REZ("zp,rel", "%i %p,%q", 3);
+   REZ("zp,rel", "%i %p,%q", 2);
 
    /** The short name of the addressing mode. */
    private String name;
@@ -184,7 +184,9 @@ public enum CpuAddressingMode {
    /** The template for an instruction using the addressing mode. */
    private String template;
 
-   /** The number of bytes that an instruction takes up when using the addressing mode. This includes both opcode and operands. */
+   /**
+    * The number of bytes that the operands of the instruction uses. This does not include the bytes used by the opcode.
+    * TODO: This does not take into account word-relative branches and immediate word*/
    private int bytes;
 
    CpuAddressingMode(String name, String template, int bytes) {
@@ -193,6 +195,12 @@ public enum CpuAddressingMode {
       this.name = name;
    }
 
+   /**
+    * Get the number of bytes that the operands of the instruction uses. This does not include the bytes used by the opcode.
+    * NOTE: This misreports number of bytes for instructions that use immediate word or long relative.
+    * TODO: This does not take into account word-relative branches and immediate word
+    * @return The number of bytes.
+    */
    public int getBytes() {
       return bytes;
    }
diff --git a/src/main/java/dk/camelot64/cpufamily6502/CpuOpcode.java b/src/main/java/dk/camelot64/cpufamily6502/CpuOpcode.java
index 7fcfe0c0f..4454b0e58 100644
--- a/src/main/java/dk/camelot64/cpufamily6502/CpuOpcode.java
+++ b/src/main/java/dk/camelot64/cpufamily6502/CpuOpcode.java
@@ -1,6 +1,7 @@
 package dk.camelot64.cpufamily6502;
 
 import java.util.Arrays;
+import java.util.List;
 
 /** A specific opcode in the instruction set of a 6502 family CPU. */
 public class CpuOpcode {
@@ -65,13 +66,18 @@ public class CpuOpcode {
       return cycles;
    }
 
+   /** Opcodes that use an extra byte for their operand that the addressing mode reports. This is immediate word and long branches.
+    * The format of the string is <code>mnemonic + " " +  addressingMode</code> */
+   public static List<String> LONG_MNEMONICS = Arrays.asList("phw #imm", "lbra rel", "lbne rel", "lbeq rel", "lbcc rel", "lbcs rel", "lbmi rel", "lbpl rel", "lbvs rel", "lbvc rel", "lbsr rel" );
+
    /**
     * Get the number of bytes the instruction with operands takes up in memory
     *
     * @return The number of bytes.
     */
    public int getBytes() {
-      return addressingMode.getBytes();
+      final int numBytes = opcode.length + addressingMode.getBytes() + (LONG_MNEMONICS.contains(mnemonic+" "+addressingMode.getName())?1:0);
+      return numBytes;
    }
 
    /**
@@ -85,16 +91,6 @@ public class CpuOpcode {
       return opcode;
    }
 
-   /**
-    * Determines if this instruction has a specific single byte opcode
-    *
-    * @param opcode The byte opcode to check
-    * @return true if this instruction has a 1-byte opcode that matches the passed value.
-    */
-   public boolean hasOpcode(int opcode) {
-      return this.opcode.length == 1 && this.opcode[0] == (byte) opcode;
-   }
-
    /**
     * Get the printed ASM code for the instruction with an operand value.
     * This prints to the syntax that KickAssembler expects.
diff --git a/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentInstance.java b/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentInstance.java
index 364366709..53a1e2c65 100644
--- a/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentInstance.java
+++ b/src/main/java/dk/camelot64/kickc/fragment/AsmFragmentInstance.java
@@ -181,17 +181,17 @@ public class AsmFragmentInstance {
    private static class AsmSequenceGenerator extends KickCParserBaseVisitor {
 
       private final String name;
-      private final AsmProgram program;
+      private final AsmProgram asmProgram;
       private final AsmFragmentInstance fragmentInstance;
 
-      public AsmSequenceGenerator(String name, AsmFragmentInstance fragmentInstance, AsmProgram program) {
+      public AsmSequenceGenerator(String name, AsmFragmentInstance fragmentInstance, AsmProgram asmProgram) {
          this.name = name;
          this.fragmentInstance = fragmentInstance;
-         this.program = program;
+         this.asmProgram = asmProgram;
       }
 
-      public AsmProgram getProgram() {
-         return program;
+      public AsmProgram getAsmProgram() {
+         return asmProgram;
       }
 
       public void generate(KickCParser.AsmLinesContext context) {
@@ -200,14 +200,14 @@ public class AsmFragmentInstance {
 
       @Override
       public Object visitAsmLabelName(KickCParser.AsmLabelNameContext ctx) {
-         program.addLine(new AsmLabel(ctx.ASM_NAME().getText()));
+         asmProgram.addLine(new AsmLabel(ctx.ASM_NAME().getText()));
          return null;
       }
 
       @Override
       public Object visitAsmLabelMulti(KickCParser.AsmLabelMultiContext ctx) {
          String label = ctx.ASM_MULTI_NAME().getText();
-         program.addLine(new AsmLabel(label));
+         asmProgram.addLine(new AsmLabel(label));
          return null;
       }
 
@@ -217,7 +217,7 @@ public class AsmFragmentInstance {
          for(int i = 1; i < ctx.getChildCount(); i = i + 2) {
             values.add(ctx.getChild(i).getText());
          }
-         program.addLine(new AsmDataNumeric(null, AsmDataNumeric.Type.BYTE, values));
+         asmProgram.addLine(new AsmDataNumeric(null, AsmDataNumeric.Type.BYTE, values));
          return null;
       }
 
@@ -231,7 +231,7 @@ public class AsmFragmentInstance {
             instruction = (AsmInstruction) this.visit(paramModeCtx);
          }
          if(instruction != null) {
-            program.addLine(instruction);
+            asmProgram.addLine(instruction);
          } else {
             throw new RuntimeException("Error parsing ASM fragment line " + name + ".asm\n - Line: " + ctx.getText());
          }
@@ -334,7 +334,7 @@ public class AsmFragmentInstance {
          AsmParameter param2 = operand2Ctx == null ? null : (AsmParameter) this.visit(operand2Ctx);
          // Convert to ZP-addressing mode if possible
          boolean isZp = param1 != null && param1.isZp();
-         CpuOpcode cpuOpcode = this.fragmentInstance.fragmentTemplate.getTargetCpu().getCpu65xx().getOpcode(mnemonic, addressingMode, isZp);
+         CpuOpcode cpuOpcode = this.getAsmProgram().getTargetCpu().getCpu65xx().getOpcode(mnemonic, addressingMode, isZp);
          String operand1 = param1 == null ? null : param1.getParam();
          String operand2 = param2 == null ? null : param2.getParam();
          if(cpuOpcode == null) {
diff --git a/src/test/java/dk/camelot64/cpufamily6502/TestCpuFamilyKickAssCompatibility.java b/src/test/java/dk/camelot64/cpufamily6502/TestCpuFamilyKickAssCompatibility.java
index ab0a401cd..6394c5c81 100644
--- a/src/test/java/dk/camelot64/cpufamily6502/TestCpuFamilyKickAssCompatibility.java
+++ b/src/test/java/dk/camelot64/cpufamily6502/TestCpuFamilyKickAssCompatibility.java
@@ -8,8 +8,7 @@ import org.junit.Test;
 
 import java.util.*;
 
-import static junit.framework.TestCase.assertNotNull;
-import static junit.framework.TestCase.assertTrue;
+import static junit.framework.TestCase.*;
 
 public class TestCpuFamilyKickAssCompatibility {
 
@@ -49,41 +48,57 @@ public class TestCpuFamilyKickAssCompatibility {
          assertNotNull("KickAss CPU " + kaCpu.name + " does not know the KickC CPU " + kcCpu.getName() + " mnemonic", kcOpcode.getMnemonic());
          final List<_65xxArgType> kaArgTypes = kaAddressingModeMap.get(kcOpcode.getAddressingMode());
          assertNotNull("KickAss addressing mode not found " + kcOpcode.getAddressingMode().getName(), kaArgTypes);
-         // Try each argtype
+         // Try each argtype to find the one that works
          boolean found = false;
          for(_65xxArgType kaArgType : kaArgTypes) {
             final int kaArgTypeIdx = kaArgType.getIdNo();
-            if(kaOpcodes!=null && kaOpcodes.length>kaArgTypeIdx) {
+            if(kaOpcodes != null && kaOpcodes.length > kaArgTypeIdx) {
                final int kaOpcodeRaw = kaOpcodes[kaArgTypeIdx];
                if(kaOpcodeRaw >= 0) {
                   found = true;
-                  int[] kaOpcode;
-                  if(kcOpcode.getOpcode().length==1) {
-                     kaOpcode  = new int[]{kaOpcodeRaw};
-                  }  else {
-                     List<Integer> kaOpcodeList = new ArrayList<>();
-                     if(CPU_45GS02.R32_MNEMONICS.contains(kcOpcode.getMnemonic())) {
-                        kaOpcodeList.add((int)CPU_45GS02.R32_OPCODE_PREFIX);
-                        kaOpcodeList.add((int)CPU_45GS02.R32_OPCODE_PREFIX);
-                     }
-                     if (kaArgType == _65xxArgType.indirect32ZeropageZ || kaArgType == _65xxArgType.indirect32Zeropage) {
-                        // Make sure the prefix is unsigned
-                        kaOpcodeList.add(CPU_45GS02.A32_OPCODE_PREFIX&0xff);
-                     }
-                     kaOpcodeList.add(kaOpcodeRaw);
-                     kaOpcode = kaOpcodeList.stream().mapToInt(i->i).toArray();
-                  }
+                  int[] kaOpcode = getKAOpcode(kaOpcodeRaw, kaArgType, kcOpcode.getMnemonic());
                   Assert.assertArrayEquals("KickAss opcode not matching for mnemonic " + kcOpcode.toString(), kcOpcode.getOpcode(), kaOpcode);
+
+                  int kaByteSize = kaOpcode.length + kaArgType.getByteSize();
+                  assertEquals("KickAss opcode byte size not matching KickC byte size "+kcOpcode.toString(), kcOpcode.getBytes(), kaByteSize);
                }
             }
          }
          assertTrue("KickAss opcode not found for mnemonic " + kcOpcode.toString(), found);
       }
 
+      // Test that each KickAss opcode has a matching KickC opcode
+
+
+   }
+
+   /**
+    * Convert KickAssembler opcode to int array, that also contains the prefix opcodes used by 45GS02.
+    *
+    * @param kaOpcodeRaw The "raw" one-byte opcode
+    * @param kaArgType The addressing mode
+    * @param mnemonic The instruction mnemonic
+    * @return The opcode list.
+    */
+   private int[] getKAOpcode(int kaOpcodeRaw, _65xxArgType kaArgType, String mnemonic) {
+      List<Integer> kaOpcodeList = new ArrayList<>();
+      if(CPU_45GS02.R32_MNEMONICS.contains(mnemonic)) {
+         // Make sure the prefix is unsigned
+         kaOpcodeList.add((int) CPU_45GS02.R32_OPCODE_PREFIX & 0xff);
+         kaOpcodeList.add((int) CPU_45GS02.R32_OPCODE_PREFIX & 0xff);
+      }
+      if(kaArgType == _65xxArgType.indirect32ZeropageZ || kaArgType == _65xxArgType.indirect32Zeropage) {
+         // Make sure the prefix is unsigned
+         kaOpcodeList.add(CPU_45GS02.A32_OPCODE_PREFIX & 0xff);
+      }
+      kaOpcodeList.add(kaOpcodeRaw);
+      int[] kaOpcode = kaOpcodeList.stream().mapToInt(i -> i).toArray();
+      return kaOpcode;
    }
 
    /**
     * Get the KickAss ArgType that matches a KickC addressing mode.
+    *
     * @return The argtype.
     */
    Map<CpuAddressingMode, List<_65xxArgType>> getKAAddressingModeMap() {
@@ -107,7 +122,6 @@ public class TestCpuFamilyKickAssCompatibility {
       map.put(CpuAddressingMode.ISY, Collections.singletonList(_65xxArgType.indirectStackZeropageY));
       map.put(CpuAddressingMode.REL, Arrays.asList(_65xxArgType.relative, _65xxArgType.relativeWord));
       map.put(CpuAddressingMode.REZ, Collections.singletonList(_65xxArgType.zeropageRelative));
-      // TODO: Handle Immediate Word, relative Word
       return map;
    }