diff --git a/DevCPU/src/devcpu/emulation/DCPU.java b/DevCPU/src/devcpu/emulation/DCPU.java
index f081db1..45fe77d 100644
--- a/DevCPU/src/devcpu/emulation/DCPU.java
+++ b/DevCPU/src/devcpu/emulation/DCPU.java
@@ -12,6 +12,8 @@
  */
 public class DCPU
 {
+  private static final boolean SHIFT_DISTANCE_5_BITS = true;
+
   private static final boolean DISASSEMBLE = false;
   public char[] ram = new char[65536];
   public char pc;
@@ -225,14 +227,14 @@ public static int getInstructionLength(char opcode) {
       cmd = opcode >> 5 & 0x1F;
       if (cmd > 0) {
         int atype = opcode >> 10 & 0x3F;
-        if (((atype & 0xF8) == 16) || (atype == 31) || (atype == 30)) len++; 
+        if (((atype & 0xF8) == 16) || (atype == 26) || (atype == 31) || (atype == 30)) len++; 
       }
     }
     else {
       int atype = opcode >> 5 & 0x1F;
       int btype = opcode >> 10 & 0x3F;
-      if (((atype & 0xF8) == 16) || (atype == 31) || (atype == 30)) len++;
-      if (((btype & 0xF8) == 16) || (btype == 31) || (btype == 30)) len++;
+      if (((atype & 0xF8) == 16) || (atype == 26) || (atype == 31) || (atype == 30)) len++;
+      if (((btype & 0xF8) == 16) || (atype == 26) || (btype == 31) || (btype == 30)) len++;
     }
     return len;
   }
@@ -384,45 +386,49 @@ public void tick() {
       case 2:{ //ADD
         cycles++;
         int val = b + a;
-        b = (char)val;
+        set(baddr, (char)val);
         ex = (char)(val >> 16);
-        break;
+        return;
       }case 3:{ //SUB
         cycles++;
         int val = b - a;
-        b = (char)val;
+        set(baddr, (char)val);
         ex = (char)(val >> 16);
-        break;
+        return;
       }case 4:{ //MUL
         cycles++;
         int val = b * a;
-        b = (char)val;
+        set(baddr, (char)val);
         ex = (char)(val >> 16);
-        break;
+        return;
       }case 5:{ //MLI
         cycles++;
         int val = (short)b * (short)a;
-        b = (char)val;
+        set(baddr, (char)val);
         ex = (char)(val >> 16);
-        break;
+        return;
       }case 6:{ //DIV
         cycles += 2;
         if (a == 0) {
-          b = ex = 0;
+          set(baddr, (char) 0);
+          ex = 0;
+          return;
         } else {
-          b /= a;
-          ex = (char)((b << 16) / a);
+          set(baddr, (char) (b / a));
+          ex = (char) (((long) b << 16) / a);
+          return;
         }
-        break;
       }case 7:{ //DVI
         cycles += 2;
         if (a == 0) {
-          b = ex = 0;
+          set(baddr, (char) 0);
+          ex = 0;
+          return;
         } else {
-          b = (char)((short)b / (short)a);
-          ex = (char)(((short)b << 16) / (short)a);
+          set(baddr, (char) ((short) b / (short) a));
+          ex = (char) ((b << 16) / ((short) a));
+          return;
         }
-        break;
       }case 8: //MOD
         cycles += 2;
         if (a == 0)
@@ -449,17 +455,30 @@ public void tick() {
         b = (char)(b ^ a);
         break;
       case 13: //SHR
-        ex = (char)(b << 16 >> a);
-        b = (char)(b >>> a);
-        break;
+        if(!SHIFT_DISTANCE_5_BITS && a > 31) {
+          set(baddr, (char) 0);
+          ex = (char) 0;
+        } else {
+          set(baddr, (char) (b >>> a));
+          ex = (char) (b << 16 >>> a);
+        }
+        return;
       case 14: //ASR
-        ex = (char)((short)b << 16 >>> a);
-        b = (char)((short)b >> a);
-        break;
+        if(!SHIFT_DISTANCE_5_BITS && a > 31) {
+          a = 31;
+        }
+        set(baddr, (char)((short)b >> a));
+        ex = (char)(b << 16 >> a);
+        return;
       case 15: //SHL
-        ex = (char)(b << a >> 16);
-        b = (char)(b << a);
-        break;
+        if(!SHIFT_DISTANCE_5_BITS && a > 31) {
+          set(baddr, (char) 0);
+          ex = (char) 0;
+        } else {
+          set(baddr, (char) (b << a));
+          ex = (char) (b << a >> 16);
+        }
+        return;
       case 16: //IFB
         cycles++;
         if ((b & a) == 0) skip();
@@ -495,15 +514,15 @@ public void tick() {
       case 26:{ //ADX
         cycles++;
         int val = b + a + ex;
-        b = (char)val;
+        set(baddr, (char)val);
         ex = (char)(val >> 16);
-        break;
+        return;
       }case 27:{ //SBX
         cycles++;
         int val = b - a + ex;
-        b = (char)val;
+        set(baddr, (char)val);
         ex = (char)(val >> 16);
-        break;
+        return;
       }case 30: //STI
         b = a;
         set(baddr, b);