diff --git a/c_os/devices/PCSPK.cc b/c_os/devices/PCSPK.cc
index ccefa71..0424ef0 100755
--- a/c_os/devices/PCSPK.cc
+++ b/c_os/devices/PCSPK.cc
@@ -56,23 +56,6 @@ void PCSPK::off() {
     ppi.outb((status >> 2) << 2);  // Lautsprecher ausschalten
 }
 
-/*****************************************************************************
- * Methode:         PCSPK::readCounter                                       *
- *---------------------------------------------------------------------------*
- * Beschreibung:    Zaehler von PIT Channel 0 auslesen.                      * 
- *                  (wird fuer delay benoetigt).                             *
- *                                                                           *
- * Rückgabewerte:   counter                                                  *
- *****************************************************************************/
-inline unsigned int PCSPK::readCounter() {
-    unsigned char lo, hi;
-
-    control.outb(0x0);  // Latch Command
-    lo = data0.inb();   // Lobyte des Counters auslesen
-    hi = data0.inb();   // Hibyte des Counters auslesen
-    return (hi << 8) | lo;
-}
-
 /*****************************************************************************
  * Methode:         PCSPK::delay                                             *
  *---------------------------------------------------------------------------*
@@ -84,6 +67,11 @@ inline void PCSPK::delay(int time) {
 
     /* Hier muess Code eingefuegt werden */
 
+    unsigned long start_time = systime;
+
+    // systime is incremented in 10ms steps
+    while ((systime - start_time) * 10 < time) {}
+
 }
 
 /*****************************************************************************
diff --git a/c_os/devices/PCSPK.h b/c_os/devices/PCSPK.h
index 7ce9ac4..bc79fee 100755
--- a/c_os/devices/PCSPK.h
+++ b/c_os/devices/PCSPK.h
@@ -71,9 +71,6 @@ private:
     // Verzoegerung um X ms (in 1ms Schritten; Min. 1ms)
     inline void delay(int time);
 
-    // Zaehler von PIT Channel 0 auslesen (wird fuer delay benoetigt)
-    inline unsigned int readCounter();
-
 public:
     // Konstruktor. Initialisieren der Ports.
     PCSPK() : control(0x43), data0(0x40), data2(0x42), ppi(0x61) {}
diff --git a/c_os/main.cc b/c_os/main.cc
index 15a6abc..646d83a 100755
--- a/c_os/main.cc
+++ b/c_os/main.cc
@@ -75,6 +75,8 @@ int main() {
     // scheduler.ready(new CoopThreadDemo());
     // scheduler.ready(new VBEdemo()); // Switch to VESA graphics mode
 
+    // pcspk.tetris();
+
     // Scheduler starten (schedule() erzeugt den Idle-Thread)
     scheduler.schedule();