get prescaler factor

de/darkress/pic16f84sim/microcontroller/Memory.java

@@ -121,6 +121,11 @@ public class Memory
         memory[0x8A] = data & 0x1F;
     }
 
+    public static int getOption()
+    {
+        return memory[0x81];
+    }
+
     public static boolean getZeroBit()
     {
         return (memory[0x03] & 0x04) == 0x04;

de/darkress/pic16f84sim/microcontroller/Timer.java

@@ -0,0 +1,19 @@
+package de.darkress.pic16f84sim.microcontroller;
+
+public class Timer
+{
+    private boolean getPrescalerAsssignment() {
+        return (Memory.getOption() & 0x08) == 0x08;
+    }
+
+    private int getPrescalerFactor() {
+        final int MULTIPLIER = 2;
+        int prescalerPower = Memory.getOption() & 0x07;
+        int prescaler = (int)Math.pow(2, prescalerPower);
+        if(!getPrescalerAsssignment())
+        {
+            return prescaler * MULTIPLIER;
+        }
+        return prescaler;
+    }
+}