diff --git a/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/app/TimeCalcKeyAdapter.java b/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/app/TimeCalcKeyAdapter.java
index 2c94382..2da74fb 100644
--- a/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/app/TimeCalcKeyAdapter.java
+++ b/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/app/TimeCalcKeyAdapter.java
@@ -129,6 +129,7 @@ public class TimeCalcKeyAdapter extends KeyAdapter {
             
             case KeyEvent.VK_U: {
                 int ms_ = msToAdd;
+                System.out.println("going to add ms:" +msToAdd);
                 int s_ = msToAdd / 1000;
                 ms_ = ms_ - s_ * 1000;
                 int m_ = msToAdd / 1000 / 60;
@@ -181,9 +182,12 @@ public class TimeCalcKeyAdapter extends KeyAdapter {
                 final double newSpeed = this.mainWindow.getSpeed();
                 
                 if(oldSpeed != newSpeed) {
+                    TTime t= TTime.ofMilliseconds(((int)(Math.pow(2,newSpeed) * 1000)));
                 Utils.showNotification("Speed was changed from " + 
                         ((int)oldSpeed) + 
-                        " to: " + ((int)newSpeed) + " (" + (NumberFormats.FORMATTER_TWO_DECIMAL_PLACES.format(Math.pow(2, newSpeed))) + ") (" + (newSpeed <= 21 ? TTime.ofMilliseconds(((int)(Math.pow(2,newSpeed) * 1000))) : "many") +" /1s)");
+                        " to: " + ((int)newSpeed) + " (" + (NumberFormats.FORMATTER_FIVE_DECIMAL_PLACES.format(Math.pow(2, newSpeed))) + ") (" + 
+                        (newSpeed <= -10 ? "few" : (newSpeed <=21 ? t : "many"))
+                        +" /1s)");
                 } else {
                     if(decrease){
                     Utils.showNotification("Current speed cannot be decreased: " + 
diff --git a/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/windows/MainWindow.java b/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/windows/MainWindow.java
index af38566..c1d3ea7 100644
--- a/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/windows/MainWindow.java
+++ b/modules/time-calc-app/src/main/java/org/nanoboot/utils/timecalc/swing/windows/MainWindow.java
@@ -829,6 +829,28 @@ public class MainWindow extends TWindow {
               timeCalcConfiguration.testEnabledProperty.setValue(false);
               return;
           }
+          if(speed < -6) {
+              if(speed == -7) {
+                  if(Math.random() > 0.5) {
+                      return;
+                  }
+              }
+              if(speed == -8) {
+                  if(Math.random() > 0.25) {
+                      return;
+                  }
+              }
+              if(speed == -9) {
+                  if(Math.random() > 0.125) {
+                      return;
+                  }
+              }
+              if(speed == -10) {
+                  if(Math.random() > 0.625) {
+                      return;
+                  }
+              }
+          }
           if(timeCalcConfiguration.testEnabledProperty.isDisabled()) {
               timeCalcConfiguration.testEnabledProperty.enable();
           }
@@ -853,7 +875,7 @@ public class MainWindow extends TWindow {
           if(time.millisecondCustomProperty.getValue() == Integer.MAX_VALUE) {
               time.millisecondCustomProperty.setValue(time.millisecondProperty.getValue());
           }
-          int msShouldBeAdded = (int) (Math.pow(2, speed) * 100d);
+          int msShouldBeAdded = speed < -6 ? 1 : (int) (Math.pow(2, speed) * 100d);
           this.timeCalcKeyAdapter.setMsToAdd(msShouldBeAdded);
           this.timeCalcKeyAdapter.processShifCtrlAltModeKeyCodes(KeyEvent.VK_U, true, false, false);
 
@@ -1279,12 +1301,13 @@ public class MainWindow extends TWindow {
         if(speed == Integer.MIN_VALUE) {
             speed = 0;
         }
-        if(speed == -3){
+        if(speed == MIN_SPEED){
             //nothing to do
             return;
         }
         --this.speed;
     }
+    public static final int MIN_SPEED = -10;
     
     public int getSpeed() {
         return speed;