diff --git a/part12-wgt/examples/wgt03.c b/part12-wgt/examples/wgt03.c
new file mode 100644
index 0000000..53b4904
--- /dev/null
+++ b/part12-wgt/examples/wgt03.c
@@ -0,0 +1,147 @@
+#include "wgt.h"
+
+// ######## REQUIRED FUNCTIONS ########
+
+unsigned long state0 = 1000;
+unsigned long state1 = 2000;
+
+unsigned long rand(void)
+{
+    unsigned long s1 = state0;
+    unsigned long s0 = state1;
+
+    state0 = s0;
+    s1 ^= s1 << 23;
+    s1 ^= s1 >> 17;
+    s1 ^= s0;
+    s1 ^= s0 >> 26;
+    state1 = s1;
+
+    return state0 + state1;
+}
+
+void wait_msec(unsigned int n)
+{
+    register unsigned long f, t, r;
+
+    // Get the current counter frequency
+    asm volatile ("mrs %0, cntfrq_el0" : "=r"(f));
+    // Read the current counter
+    asm volatile ("mrs %0, cntpct_el0" : "=r"(t));
+    // Calculate expire value for counter
+    t+=((f/1000)*n)/1000;
+    do{asm volatile ("mrs %0, cntpct_el0" : "=r"(r));}while(r<t);
+}
+
+// ######## STUB FUNCTIONS ########
+
+unsigned int kb = 0;
+
+unsigned int kbhit(void) {
+    kb++;
+    return kb / 500;
+}
+
+void getch(void) {
+    wait_msec(0x500000);
+    kb = 0;
+}
+
+// ######## WGT EXAMPLES ########
+
+#define TIMERSPEED 60     /* timer_routine is called 60 times per second */
+
+int timer;                /* Counts how many times it has been called */ 
+int clearcount;           /* Counts the number of screen clears. */
+
+int curx = 0;
+int cury = 0;
+
+void debugstr(char *str) {
+    if (curx + (strlen(str) * 8)  >= 1920) {
+       curx = 0; cury += 8;
+    }
+    if (cury + 8 >= 1080) {
+       cury = 0;
+    }
+    wtextcolor(vgapal[15]);
+    wouttextxy (curx, cury, NULL, str);
+
+    curx += (strlen(str) * 8);
+}
+
+void debugcrlf(void) {
+    curx = 0; cury += 8;
+}
+
+void debugch(unsigned char b) {
+    unsigned int n;
+    int c;
+    for(c=4;c>=0;c-=4) {
+        n=(b>>c)&0xF;
+        n+=n>9?0x37:0x30;
+        debugstr((char *)&n);
+    }
+    debugstr(" ");
+}
+
+void debughex(unsigned int d) {
+    unsigned int n;
+    int c;
+    for(c=28;c>=0;c-=4) {
+        n=(d>>c)&0xF;
+        n+=n>9?0x37:0x30;
+        debugstr((char *)&n);
+    }
+    debugstr(" ");
+}
+
+void timer_routine (void)
+{
+  timer++;
+}
+
+void wgt03()
+{
+  vga256 ();                     /* Initialize WGT system        */
+
+  debugstr ("WGT Example #3"); debugcrlf(); debugcrlf(); 
+  debugstr ("This program will use the wcls routine to clear the screen"); debugcrlf();
+  debugstr ("using random colors as fast as it can until you press a key."); debugcrlf();
+  debugstr ("It will then report the highest frame rate possible on your computer."); debugcrlf(); debugcrlf(); debugcrlf();
+  debugstr ("Press any key to continue."); debugcrlf();
+  getch ();
+
+  clearcount = 0;
+  timer = 0;
+
+  winittimer ();
+  wstarttimer (timer_routine, TIMERSPEED);
+
+  curx = 0;
+  cury = 0;
+
+  while (!kbhit ())
+  {
+     wcls(vgapal[rand() % 256]); /* Clear with random color out of 256 */
+     clearcount++;
+  }
+
+  wstoptimer ();
+  wdonetimer ();
+
+  getch ();
+
+  wcls(vgapal[0]);
+
+  unsigned int fps = clearcount / (timer / TIMERSPEED);
+  debughex(fps); debugstr("frames per second"); debugcrlf();
+  debugstr ("This is the highest frame rate your computer can produce for full screen\n"); debugcrlf();
+  debugstr ("animation."); debugcrlf();
+}
+
+void main()
+{
+    wgt03();
+    while (1);
+}
diff --git a/part12-wgt/examples/wgt08.c b/part12-wgt/examples/wgt08.c
index 2061710..802e10d 100644
--- a/part12-wgt/examples/wgt08.c
+++ b/part12-wgt/examples/wgt08.c
@@ -69,7 +69,7 @@ void wgt08()
 
     getch ();
 
-    wcls (0);
+    wcls (vgapal[0]);
     for (x = 1; x < 10000; x++)        /* try filling 10,000 random pixels */
     {
         wsetcolor (vgapal[rand() % 255]);
diff --git a/part12-wgt/lib/mem.c b/part12-wgt/lib/mem.c
index 1190709..4e772db 100644
--- a/part12-wgt/lib/mem.c
+++ b/part12-wgt/lib/mem.c
@@ -3,7 +3,7 @@ extern unsigned char _end[];
 // Define the heap
 
 unsigned char *HEAP_START = &_end[0];
-unsigned int   HEAP_SIZE  = 0x40000000; // Max heap size is 1Gb
+unsigned int   HEAP_SIZE  = 0x30000000; // Max heap size is 768Mb
 unsigned char *HEAP_END;
 
 // Set up some globals
diff --git a/part12-wgt/wgt.h b/part12-wgt/wgt.h
index 1b55e4f..a550572 100644
--- a/part12-wgt/wgt.h
+++ b/part12-wgt/wgt.h
@@ -86,3 +86,8 @@ short wgetblockwidth (block ptr);
 short wgetblockheight (block ptr);
 block wnewblock (short x, short y, short x2, short y2);
 block wallocblock (short width, short height);
+void wdonetimer (void);
+void winittimer (void);
+void wsettimerspeed (int speed);
+void wstarttimer (void (*rout)(), int speed);
+void wstoptimer (void);
diff --git a/part12-wgt/wticker.c b/part12-wgt/wticker.c
new file mode 100644
index 0000000..daaff53
--- /dev/null
+++ b/part12-wgt/wticker.c
@@ -0,0 +1,67 @@
+#include "wgt.h"
+#include "include/multicore.h"
+
+short ticker_speed, ticker_running;
+unsigned int ticker_interval;
+void (*ticker_routine)();
+
+void twait(unsigned int n)
+{
+   register unsigned long f, t, r;
+
+   // Get the current counter frequency
+   asm volatile ("mrs %0, cntfrq_el0" : "=r"(f));
+   // Read the current counter
+   asm volatile ("mrs %0, cntpct_el0" : "=r"(t));
+   // Calculate expire value for counter
+   t+=((f/1000)*n)/1000;
+   do{asm volatile ("mrs %0, cntpct_el0" : "=r"(r));}while(r<t);
+}
+
+void widletimer (void)
+{
+   /* do nothing */
+}
+
+void winittimer (void)
+{
+   ticker_running = 0;
+   wsettimerspeed (60);
+}
+
+void wdonetimer (void)
+{
+   wsettimerspeed (60);
+   ticker_running = 0;
+}
+
+void wsettimerspeed (int speed)
+{
+   ticker_speed = speed;
+   ticker_interval = 1000000 / speed;
+}
+
+void wtick(void)
+{
+   clear_core1();
+
+   while (ticker_running) {
+      twait(ticker_interval);
+      ticker_routine();
+   }
+}
+
+void wstarttimer (void (*Rout)(), int speed)
+{
+   ticker_routine = Rout;
+   wsettimerspeed (speed);
+   ticker_running = 1;
+
+   start_core1(wtick);
+}
+
+void wstoptimer (void)
+{
+   ticker_routine = widletimer;
+   wsettimerspeed (19);
+}