6 files changed, 35 insertions, 4 deletions
diff --git a/src/main/kotlin/BitManipulation.kt b/src/main/kotlin/BitManipulation.kt
index b655718..430d840 100644
--- a/src/main/kotlin/BitManipulation.kt
+++ b/src/main/kotlin/BitManipulation.kt
@@ -28,12 +28,12 @@ object BitManipulation {
     }
   }
 
-  fun isSignedBitNegative(value: Int): Boolean {
+  fun isSignedByteNegative(value: Int): Boolean {
     return value and (1 shl 7) != 0
   }
 
   fun getAbsoluteValue(value: Int ): Int{
-    return if(isSignedBitNegative(value)) {
+    return if(isSignedByteNegative(value)) {
       0x0100 - value // 1 00000000 - 1xxxxxx = value, due to 2s compliment
     } else {
       value
diff --git a/src/main/kotlin/cpu/Cpu.kt b/src/main/kotlin/cpu/Cpu.kt
index feb89bc..ce5ba43 100644
--- a/src/main/kotlin/cpu/Cpu.kt
+++ b/src/main/kotlin/cpu/Cpu.kt
@@ -18,6 +18,7 @@ class Cpu {
     stdCommandGroup.putAll(arithmetic16Bit)
     stdCommandGroup.putAll(misc)
     stdCommandGroup.putAll(rotates)
+    stdCommandGroup.putAll(jumps)
     standardOpcodes = stdCommandGroup.toMap()
 
     val extCommandGroup: MutableMap<Int, Operation> = mutableMapOf()
diff --git a/src/main/kotlin/cpu/Registers.kt b/src/main/kotlin/cpu/Registers.kt
index 54539a8..81db1b0 100644
--- a/src/main/kotlin/cpu/Registers.kt
+++ b/src/main/kotlin/cpu/Registers.kt
@@ -131,6 +131,14 @@ class Registers {
     return currentSP
   }
 
+  fun addSignedByteToPC(byte: Int) {
+    PC = if (bm.isSignedByteNegative(byte)) {
+      (PC - bm.getAbsoluteValue(byte)) and 0xFFFF
+    } else {
+      (PC + bm.getAbsoluteValue(byte)) and 0xFFFF
+    }
+  }
+
   fun getFlag(flag: Flag): Int {
     return (F shr flag.bitPosition) and 0x01
   }
diff --git a/src/main/kotlin/cpu/opcodes/Arithmetic16Bit.kt b/src/main/kotlin/cpu/opcodes/Arithmetic16Bit.kt
index 0c2c9cb..0eff88a 100644
--- a/src/main/kotlin/cpu/opcodes/Arithmetic16Bit.kt
+++ b/src/main/kotlin/cpu/opcodes/Arithmetic16Bit.kt
@@ -17,7 +17,7 @@ var arithmetic16Bit = mapOf(
 
     val absoluteValue = bm.getAbsoluteValue(a[0])
 
-    if (bm.isSignedBitNegative(a[0])) {
+    if (bm.isSignedByteNegative(a[0])) {
       r.setFlagFromBool(Flag.HALF_CARRY, r.SP and 0x0F < absoluteValue and 0x0F)
       r.setFlagFromBool(Flag.CARRY,r.SP and 0xFF < absoluteValue)
       r.SP = r.SP - absoluteValue
diff --git a/src/main/kotlin/cpu/opcodes/Jumps.kt b/src/main/kotlin/cpu/opcodes/Jumps.kt
new file mode 100644
index 0000000..6e0ea3e
--- /dev/null
+++ b/src/main/kotlin/cpu/opcodes/Jumps.kt
@@ -0,0 +1,22 @@
+package cpu.opcodes
+
+import cpu.Operation
+import cpu.Registers.Flag
+import BitManipulation as bm
+
+val jumps = mapOf(
+
+  0xC3 to Operation("JP nn", 2, 12, {r, _, a -> r.PC = bm.argsToWord(a)}),
+  0xC2 to Operation("JP NZ,nn", 2, 12, {r, _, a -> if(r.getFlag(Flag.ZERO) == 0) r.PC = bm.argsToWord(a)}),
+  0xCA to Operation("JP Z,nn", 2, 12, {r, _, a -> if(r.getFlag(Flag.ZERO) == 1) r.PC = bm.argsToWord(a)}),
+  0xD2 to Operation("JP NC,nn", 2, 12, {r, _, a -> if(r.getFlag(Flag.CARRY) == 0) r.PC = bm.argsToWord(a)}),
+  0xDA to Operation("JP C,nn", 2, 12, {r, _, a -> if(r.getFlag(Flag.CARRY) == 1) r.PC = bm.argsToWord(a)}),
+  0xE9 to Operation("JP (HL)", 0, 4, {r, m, _ -> r.PC = m.readByte(r.HL)}),
+
+  0x18 to Operation("JR n", 1, 8, {r, _, a -> r.addSignedByteToPC(a[0])}),
+  0x20 to Operation("JR NZ,n", 1, 8, {r, _, a -> if(r.getFlag(Flag.ZERO) == 0) r.addSignedByteToPC(a[0])}),
+  0x28 to Operation("JR Z,n", 1, 8, {r, _, a -> if(r.getFlag(Flag.ZERO) == 1) r.addSignedByteToPC(a[0])}),
+  0x30 to Operation("JR NC,n", 1, 8, {r, _, a -> if(r.getFlag(Flag.CARRY) == 0) r.addSignedByteToPC(a[0])}),
+  0x38 to Operation("JR C,n", 1, 8, {r, _, a -> if(r.getFlag(Flag.CARRY) == 1) r.addSignedByteToPC(a[0])})
+
+)
+\ No newline at end of file
diff --git a/src/main/kotlin/cpu/opcodes/Loads16Bit.kt b/src/main/kotlin/cpu/opcodes/Loads16Bit.kt
index 134b3a9..2f679c3 100644
--- a/src/main/kotlin/cpu/opcodes/Loads16Bit.kt
+++ b/src/main/kotlin/cpu/opcodes/Loads16Bit.kt
@@ -24,7 +24,7 @@ var loads16Bit = mapOf(
 
     val absoluteValue = bm.getAbsoluteValue(a[0])
 
-    if (bm.isSignedBitNegative(a[0])) {
+    if (bm.isSignedByteNegative(a[0])) {
       r.setFlagFromBool(Flag.HALF_CARRY, r.SP and 0x0F < absoluteValue and 0x0F)
       r.setFlagFromBool(Flag.CARRY,r.SP and 0xFF < absoluteValue)
       r.HL = r.SP - absoluteValue