diff --git a/jni/android_driver.c b/jni/android_driver.c
index 4b0b30a..2b31eb2 100644
--- a/jni/android_driver.c
+++ b/jni/android_driver.c
@@ -49,6 +49,7 @@ extern Kimage g_mainwin_kimage;
 
 extern int g_config_kegs_update_needed;
 extern int g_limit_speed;
+extern int g_zipgs_reg_c05a;
 
 extern word32 g_red_mask;
 extern word32 g_green_mask;
@@ -505,17 +506,14 @@ int x_diskimage(jclass diskimage_class, jobject diskimage_event) {
 
 void x_key_special(int key_id) {
   key_id = key_id & 0x7f;  // only use lower 7 bits
-  switch(key_id) {
-    case 0:
-    case 1:
-    case 2:
-    case 3:
-      g_limit_speed = key_id;
-      g_config_kegs_update_needed = 1;
-      break;
-    case 120:
-      set_halt(HALT_WANTTOQUIT);  // request kegsmain to exit
-      break;
+  if (key_id >= 0 && key_id <= 3) {
+    g_limit_speed = key_id;
+    g_config_kegs_update_needed = 1;
+  } else if (key_id >= 0x10 && key_id <= 0x1f) {
+    // run_prog() will see the change and call setup_zip_speeds()
+    g_zipgs_reg_c05a = ((key_id & 0x0f) << 4) | 0x0f;
+  } else if (key_id == 120) {
+    set_halt(HALT_WANTTOQUIT);  // request kegsmain to exit
   }
 }
 
@@ -566,12 +564,12 @@ check_input_events()
 
   // check if paused, first
   jclass cls = (*g_env)->GetObjectClass(g_env, g_thiz);
-  jmethodID mid = (*g_env)->GetMethodID(g_env, cls, "checkForPause", "(I)V");
+  jmethodID mid = (*g_env)->GetMethodID(g_env, cls, "checkForPause", "(II)V");
   (*g_env)->DeleteLocalRef(g_env, cls);
   if (mid == NULL) {
     return;
   }
-  (*g_env)->CallVoidMethod(g_env, g_thiz, mid, g_limit_speed);
+  (*g_env)->CallVoidMethod(g_env, g_thiz, mid, g_limit_speed, g_zipgs_reg_c05a);
 
   do {
     cls = (*g_env)->GetObjectClass(g_env, g_eventqueue);
diff --git a/res/values/strings.xml b/res/values/strings.xml
index e13d77b..b535c7b 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -21,6 +21,7 @@
     <item>1.0 megahertz</item>
     <item>2.8 megahertz</item>
     <item>8.0 megahertz</item>
+    <item>16.0 megahertz</item>
     <item>Unlimited</item>
   </string-array>
 
diff --git a/src/com/froop/app/kegs/KegsThread.java b/src/com/froop/app/kegs/KegsThread.java
index ddea821..5832071 100644
--- a/src/com/froop/app/kegs/KegsThread.java
+++ b/src/com/froop/app/kegs/KegsThread.java
@@ -16,7 +16,8 @@ class KegsThread extends Thread {
 
   private String mConfigFile;  // full path to config_kegs
   private Bitmap mBitmap;
-  private final AtomicInteger mCurrentSpeed = new AtomicInteger(0);
+  private final AtomicInteger mCurrentSpeedLimit = new AtomicInteger(0);
+  private final AtomicInteger mCurrentSpeedZip = new AtomicInteger(0);
   private final ReentrantLock mPauseLock = new ReentrantLock();
   private final ReentrantLock mPowerWait = new ReentrantLock();
 
@@ -50,8 +51,9 @@ class KegsThread extends Thread {
   }
 
   // Called by native thread.
-  private void checkForPause(int currentEmulationSpeed) {
-    mCurrentSpeed.set(currentEmulationSpeed);  // NOTE: This is a hack.
+  private void checkForPause(int currentEmulationSpeed, int currentZipSpeed) {
+    mCurrentSpeedLimit.set(currentEmulationSpeed);  // g_limit_speed
+    mCurrentSpeedZip.set(currentZipSpeed);          // g_zipgs_reg_c05a
     if (mPaused.get()) {
       mPauseLock.lock();
       // deadlock here until onResume.  Maybe not efficient.
@@ -147,16 +149,9 @@ class KegsThread extends Thread {
     return mPowerWait.hasQueuedThreads();
   }
 
-  public void setEmulationSpeed(int speed) {
-    // Speed matches g_limit_speed inside KEGS.
-    // Instead of a separate "control" event, key ids with bit 8 high are
-    // special events.  See android_driver.c:x_key_special()
-    getEventQueue().add(new Event.KeyKegsEvent(speed + 0x80, true));
-  }
-
-  public int getEmulationSpeed() {
-    // Equal to g_limit_speed inside KEGS.
-    return mCurrentSpeed.get();
+  public SpeedSetting getEmulationSpeed() {
+    return new SpeedSetting(getEventQueue(),
+                            mCurrentSpeedLimit.get(), mCurrentSpeedZip.get());
   }
 
   public void doWarmReset() {
diff --git a/src/com/froop/app/kegs/SpeedFragment.java b/src/com/froop/app/kegs/SpeedFragment.java
index dc3f340..f382a19 100644
--- a/src/com/froop/app/kegs/SpeedFragment.java
+++ b/src/com/froop/app/kegs/SpeedFragment.java
@@ -13,24 +13,15 @@ public class SpeedFragment extends SherlockDialogFragment {
   public Dialog onCreateDialog(Bundle savedInstanceState) {
     AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
 
-    int currentSpeed = ((KegsMain)getActivity()).getThread().getEmulationSpeed();
-    // Adjust g_limit_speed to match default item number.
-    currentSpeed--;
-    if (currentSpeed < 0) {
-      currentSpeed = 3;
-    }
+    final SpeedSetting currentSpeed = ((KegsMain)getActivity()).getThread().getEmulationSpeed();
 
     builder.setTitle(R.string.speed_title);
-    builder.setSingleChoiceItems(R.array.speed_choices, currentSpeed,
+    builder.setSingleChoiceItems(R.array.speed_choices,
+                                 currentSpeed.getMenuItem(),
         new DialogInterface.OnClickListener() {
       public void onClick(DialogInterface dialog, int item) {
         dismiss();
-        // Adjust selected item number to match g_limit_speed.
-        item++;
-        if (item > 3) {
-          item = 0;
-        }
-        ((KegsMain)getActivity()).getThread().setEmulationSpeed(item);
+        currentSpeed.setFromMenuItem(item);
       }
     });
     return builder.create();
diff --git a/src/com/froop/app/kegs/SpeedSetting.java b/src/com/froop/app/kegs/SpeedSetting.java
new file mode 100644
index 0000000..b428af1
--- /dev/null
+++ b/src/com/froop/app/kegs/SpeedSetting.java
@@ -0,0 +1,60 @@
+package com.froop.app.kegs;
+
+import android.util.Log;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+// Ugh.
+
+class SpeedSetting {
+  private ConcurrentLinkedQueue mEventQueue;
+  private int mSpeedLimit;  // 0 = unlimited, 1=1mhz, 2=2.8mhz, 3=zipgs
+  private int mSpeedZip;    // 0-15, zipgs, 0=16/16ths, 8=8/16th, 15=1/16th
+
+  public SpeedSetting(ConcurrentLinkedQueue q,
+                      int g_limit_speed, int g_zipgs_reg_c05a) {
+    mEventQueue = q;
+    mSpeedLimit = g_limit_speed;
+    mSpeedZip = (g_zipgs_reg_c05a & 0xf0) >> 4;
+  }
+
+  public int getMenuItem() {
+    // Map g_limit_speed to R.array.speed_choices
+    int item = mSpeedLimit - 1;
+    if (item < 0) {
+      item = 5;
+    }
+
+    if (mSpeedLimit == 3 && mSpeedZip < 0x08) {
+      item++;  // Bump from 8mhz item to 16mhz item
+    }
+
+    return item;
+  }
+
+  public void setFromMenuItem(int item) {
+    // Map R.array.speed_choices to g_limit_speed
+    if (item == 2) {
+      mSpeedZip = 0x08;  // limit zip to 8/16ths (8mhz)
+    } else {
+      mSpeedZip = 0x00;  // default no zip limit
+    }
+
+    mSpeedLimit = item + 1;
+    if (mSpeedLimit >= 5) {
+      mSpeedLimit = 0;
+    } else if (mSpeedLimit == 4) {
+      mSpeedLimit = 3;  // turn 16mhz setting into "zipgs" speed
+    }
+    sendUpdateEvent();
+  }
+
+  private void sendUpdateEvent() {
+    if (mEventQueue != null) {
+      // Instead of a separate "control" event, key ids with bit 8 high are
+      // special events.  See android_driver.c:x_key_special()
+      Log.w("kegs", "updating limit to " + mSpeedLimit + " " + mSpeedZip);
+      mEventQueue.add(new Event.KeyKegsEvent(0x80 + mSpeedLimit, true));
+      mEventQueue.add(new Event.KeyKegsEvent(0x80 + 0x10 + mSpeedZip, true));
+    }
+  }
+}