diff --git a/backend/shork/src/main/kotlin/internal/addressing/AddressMode.kt b/backend/shork/src/main/kotlin/internal/addressing/AddressMode.kt
index 65492580..c8810d22 100644
--- a/backend/shork/src/main/kotlin/internal/addressing/AddressMode.kt
+++ b/backend/shork/src/main/kotlin/internal/addressing/AddressMode.kt
@@ -1,32 +1,32 @@
 package software.shonk.interpreter.internal.addressing
 
 internal enum class AddressMode {
-    // #
-    IMMEDIATE,
     // $
     DIRECT,
+    // #
+    IMMEDIATE,
     // *
     A_INDIRECT,
     // @
     B_INDIRECT,
     // {
     A_PRE_DECREMENT,
-    // }
-    A_POST_INCREMENT,
     // <
     B_PRE_DECREMENT,
+    // }
+    A_POST_INCREMENT,
     // >
     B_POST_INCREMENT;
 
     override fun toString(): String {
         return when (this) {
-            IMMEDIATE -> "# (Immediate)"
             DIRECT -> "$ (Direct)"
+            IMMEDIATE -> "# (Immediate)"
             A_INDIRECT -> "* (A Indirect)"
             B_INDIRECT -> "@ (B Indirect)"
             A_PRE_DECREMENT -> "{ (A Pre Decrement)"
-            A_POST_INCREMENT -> "} (A Post Increment)"
             B_PRE_DECREMENT -> "< (B Pre Decrement)"
+            A_POST_INCREMENT -> "} (A Post Increment)"
             B_POST_INCREMENT -> "> (B Post Increment)"
         }
     }
diff --git a/backend/shork/src/test/kotlin/memory/TestAddressMode.kt b/backend/shork/src/test/kotlin/memory/TestAddressMode.kt
new file mode 100644
index 00000000..4d65254c
--- /dev/null
+++ b/backend/shork/src/test/kotlin/memory/TestAddressMode.kt
@@ -0,0 +1,212 @@
+package memory
+
+import getDefaultInternalSettings
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import software.shonk.interpreter.internal.InternalShork
+import software.shonk.interpreter.internal.addressing.AddressMode
+import software.shonk.interpreter.internal.addressing.Modifier
+import software.shonk.interpreter.internal.instruction.Add
+import software.shonk.interpreter.internal.instruction.Dat
+import software.shonk.interpreter.internal.process.Process
+import software.shonk.interpreter.internal.program.Program
+
+internal class TestAddressMode {
+    private val dat = Dat(0, 0, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+    private val settings = getDefaultInternalSettings(dat)
+    private var shork = InternalShork(settings)
+    private var memoryCore = shork.memoryCore
+    private var program = Program("add", shork)
+    private var process = Process(program, 0)
+
+    @BeforeEach
+    fun setup() {
+        shork = InternalShork(settings)
+        program = Program("add", shork)
+        process = Process(program, 0)
+        memoryCore = shork.memoryCore
+    }
+
+    @Test
+    fun `test direct`() {
+        val add = Add(1, 2, AddressMode.DIRECT, AddressMode.DIRECT, Modifier.A)
+        val dat = Dat(42, 0, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, add)
+        shork.memoryCore.storeAbsolute(1, dat)
+
+        add.execute(process, memoryCore.resolveFields(0))
+
+        val resultInstruction = shork.memoryCore.loadAbsolute(2)
+
+        assert(resultInstruction is Dat)
+        assertEquals(42, resultInstruction.aField)
+    }
+
+    @Test
+    fun `test immediate`() {
+        val add = Add(1, 5, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, add)
+
+        add.execute(process, memoryCore.resolveFields(0))
+
+        val resultInstruction = shork.memoryCore.loadAbsolute(0)
+
+        assert(resultInstruction is Add)
+        assertEquals(2, resultInstruction.aField)
+    }
+
+    @Test
+    fun `test A-Indirect`() {
+        val add = Add(1, 1, AddressMode.A_INDIRECT, AddressMode.A_INDIRECT, Modifier.A)
+        val dat = Dat(1, 0, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        val dat2 = Dat(2, 0, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, add)
+        shork.memoryCore.storeAbsolute(1, dat)
+        shork.memoryCore.storeAbsolute(2, dat2)
+
+        add.execute(process, memoryCore.resolveFields(0))
+
+        val resultInstruction = shork.memoryCore.loadAbsolute(2)
+
+        assert(resultInstruction is Dat)
+        assertEquals(4, resultInstruction.aField)
+    }
+
+    @Test
+    fun `test B-Indirect`() {
+        val add = Add(1, 1, AddressMode.B_INDIRECT, AddressMode.B_INDIRECT, Modifier.A)
+        val dat = Dat(0, 1, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        val dat2 = Dat(2, 0, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, add)
+        shork.memoryCore.storeAbsolute(1, dat)
+        shork.memoryCore.storeAbsolute(2, dat2)
+
+        add.execute(process, memoryCore.resolveFields(0))
+
+        val resultInstruction = shork.memoryCore.loadAbsolute(2)
+
+        assert(resultInstruction is Dat)
+        assertEquals(4, resultInstruction.aField)
+    }
+
+    @Test
+    fun `test A-Pre-Decrement`() {
+        val dat = Dat(3, 2, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        val add = Add(-1, 3, AddressMode.A_PRE_DECREMENT, AddressMode.IMMEDIATE, Modifier.AB)
+        val dat2 = Dat(7, 42, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, dat)
+        shork.memoryCore.storeAbsolute(1, add)
+        shork.memoryCore.storeAbsolute(2, dat2)
+
+        add.execute(process, memoryCore.resolveFields(1))
+
+        val datResult = shork.memoryCore.loadAbsolute(0)
+
+        assert(datResult is Dat)
+        assertEquals(2, datResult.aField)
+        assertEquals(2, datResult.bField)
+
+        val addResult = shork.memoryCore.loadAbsolute(1)
+
+        assert(addResult is Add)
+        assertEquals(-1, addResult.aField)
+        assertEquals(10, addResult.bField)
+
+        val dat2Result = shork.memoryCore.loadAbsolute(2)
+
+        assert(dat2Result is Dat)
+        assertEquals(7, dat2Result.aField)
+        assertEquals(42, dat2Result.bField)
+    }
+
+    @Test
+    fun `test B-Pre-Decrement`() {
+        val dat = Dat(1987, 3, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        val add = Add(-1, 3, AddressMode.B_PRE_DECREMENT, AddressMode.IMMEDIATE, Modifier.AB)
+        val dat2 = Dat(42, 7, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, dat)
+        shork.memoryCore.storeAbsolute(1, add)
+        shork.memoryCore.storeAbsolute(2, dat2)
+
+        add.execute(process, memoryCore.resolveFields(1))
+
+        val datResult = shork.memoryCore.loadAbsolute(0)
+
+        assert(datResult is Dat)
+        assertEquals(1987, datResult.aField)
+        assertEquals(2, datResult.bField)
+
+        val addResult = shork.memoryCore.loadAbsolute(1)
+
+        assert(addResult is Add)
+        assertEquals(-1, addResult.aField)
+        assertEquals(45, addResult.bField)
+
+        val dat2Result = shork.memoryCore.loadAbsolute(2)
+
+        assert(dat2Result is Dat)
+        assertEquals(42, dat2Result.aField)
+        assertEquals(7, dat2Result.bField)
+    }
+
+    @Test
+    fun `test A-Post-Increment`() {
+        val dat = Dat(2, 1984, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        val add = Add(-1, 3, AddressMode.A_POST_INCREMENT, AddressMode.IMMEDIATE, Modifier.AB)
+        val dat2 = Dat(42, 7, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, dat)
+        shork.memoryCore.storeAbsolute(1, add)
+        shork.memoryCore.storeAbsolute(2, dat2)
+
+        add.execute(process, memoryCore.resolveFields(1))
+
+        val datResult = shork.memoryCore.loadAbsolute(0)
+
+        assert(datResult is Dat)
+        assertEquals(3, datResult.aField)
+        assertEquals(1984, datResult.bField)
+
+        val addResult = shork.memoryCore.loadAbsolute(1)
+
+        assert(addResult is Add)
+        assertEquals(-1, addResult.aField)
+        assertEquals(45, addResult.bField)
+
+        val dat2Result = shork.memoryCore.loadAbsolute(2)
+
+        assert(dat2Result is Dat)
+        assertEquals(42, dat2Result.aField)
+        assertEquals(7, dat2Result.bField)
+    }
+
+    @Test
+    fun `test B-Post-Increment`() {
+        val dat = Dat(451, 2, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        val add = Add(69, -1, AddressMode.IMMEDIATE, AddressMode.B_POST_INCREMENT, Modifier.AB)
+        val dat2 = Dat(42, 7, AddressMode.IMMEDIATE, AddressMode.IMMEDIATE, Modifier.A)
+        shork.memoryCore.storeAbsolute(0, dat)
+        shork.memoryCore.storeAbsolute(1, add)
+        shork.memoryCore.storeAbsolute(2, dat2)
+
+        add.execute(process, memoryCore.resolveFields(1))
+
+        val datResult = shork.memoryCore.loadAbsolute(0)
+
+        assert(datResult is Dat)
+        assertEquals(451, datResult.aField)
+        assertEquals(3, datResult.bField)
+
+        val addResult = shork.memoryCore.loadAbsolute(1)
+
+        assert(addResult is Add)
+        assertEquals(69, addResult.aField)
+        assertEquals(-1, addResult.bField)
+
+        val dat2Result = shork.memoryCore.loadAbsolute(2)
+
+        assert(dat2Result is Dat)
+        assertEquals(42, dat2Result.aField)
+        assertEquals(76, dat2Result.bField)
+    }
+}