diff --git a/kaleid/kernel/init/init.c b/kaleid/kernel/init/init.c
index 58d4935..fb5841d 100644
--- a/kaleid/kernel/init/init.c
+++ b/kaleid/kernel/init/init.c
@@ -86,6 +86,9 @@ noreturn void BtStartKern(multiboot_info_t *mbInfo, uint mbMagic, void *codeSeg)
     // ACPI
     IoTestAcpi();
 
+    // Scheduler
+    PsInitSched();
+
     // Command line (kernel mode)
     ShStartShell();
 
diff --git a/kaleid/kernel/ke/idt.c b/kaleid/kernel/ke/idt.c
index d6fc0fc..ffc029b 100644
--- a/kaleid/kernel/ke/idt.c
+++ b/kaleid/kernel/ke/idt.c
@@ -153,7 +153,7 @@ void KeSetupIDT(void)
     KeSetIDTGate(0x1F, (ulong)isr31, codeSeg, 0x8E, 2);  // INTEL RESERVED
 
     // Set IDT IRQs Gates
-    KeSetIDTGate(0x20, (ulong)isr32, codeSeg, 0x8E, 3);
+    KeSetIDTGate(0x20, (ulong)isr32, codeSeg, 0x8E, 0);
     KeSetIDTGate(0x21, (ulong)isr33, codeSeg, 0x8E, 3);
     KeSetIDTGate(0x22, (ulong)isr34, codeSeg, 0x8E, 3);
     KeSetIDTGate(0x23, (ulong)isr35, codeSeg, 0x8E, 3);
diff --git a/kaleid/kernel/ke/pit.c b/kaleid/kernel/ke/pit.c
index 4a0ee7b..cd76135 100644
--- a/kaleid/kernel/ke/pit.c
+++ b/kaleid/kernel/ke/pit.c
@@ -25,6 +25,7 @@
 #include <lib/buf.h>
 #include <ke/time.h>
 #include <ke/idt.h>
+#include <ke/sched.h>
 
 #define COUNTDONE 1
 #define PIT_FREQUENCY 1000 // Hz = 1ms
@@ -34,6 +35,8 @@ static ulong Ticks = 0;
 static Time_t CurTime;
 static char TimeFmtBuf[22] = { 0 };
 
+extern bool PsInitialized;
+
 //
 // ISR handler for the Programmable Interval Timer
 //
@@ -53,6 +56,10 @@ static void HandlePIT(ISRFrame_t *regs)
         }
 
         KeSendEOItoPIC(0x28);
+
+        if (PsInitialized && !(Ticks % 100)) {
+            PsSchedOnTick();
+        }
     }
 }
 #pragma GCC pop_options
diff --git a/kaleid/kernel/ps/sched.c b/kaleid/kernel/ps/sched.c
index e157e0a..54a5fb4 100644
--- a/kaleid/kernel/ps/sched.c
+++ b/kaleid/kernel/ps/sched.c
@@ -26,6 +26,9 @@
 #include <ke/proc.h>
 #include <ke/sched.h>
 #include <lib/list.h>
+#include <ke/time.h>
+
+bool PsInitialized = false;
 
 //
 // For test purpose only
@@ -302,6 +305,8 @@ void PsInitSched(void)
     }
 
     PsUnlockSched();
+
+    PsInitialized = true;
 }
 
 //
@@ -311,6 +316,8 @@ void PsFiniSched(void)
 {
     assert(IdlePrioProcs && ReglPrioProcs && ServPrioProcs && TimeCritProcs);
 
+    PsInitialized = false;
+
     PsLockSched();
 
     while (IdlePrioProcs->length > 0)
@@ -372,38 +379,17 @@ void pstest(void)
     KernLog("\nIdle: ");
     PrintList(IdlePrioProcs);
 
-    int tick = 0;
-
     KernLog("\n");
 
-    while (tick < 100) {
-        //if (tick%25==0)ClearTerm(StdOut);
-        if (tick > 0 && tick != 50 && tick % 10 == 0 && KeCurProc) {
-            KernLog("Blocking current process\n");
-            PsBlockCurProc();
-        }
 
-        if (tick == 50) {
-            procs[0].procState = STATE_RUNNABLE;
-            PsSchedThisProc(&procs[0]);
-        }
+    KernLog("Tick %d - Running: ", KeGetTicks());
 
-        KernLog("Tick %d - Running: ", tick);
+    if (KeCurProc == NULL) {
+        KernLog("IDLE\n");
+    }
 
-        if (KeCurProc == NULL) {
-            KernLog("IDLE\n");
-        }
-
-        else {
-            PrintProc(KeCurProc);
-        }
-
-        PsSchedOnTick();
-
-        if (tick == 50) // already done
-            KernLog("Re-scheduling process 0\n");
-
-        tick++;
+    else {
+        PrintProc(KeCurProc);
     }
 }