Update Makefile and main with new stuff.

Makefile

@@ -5,6 +5,7 @@ SERIALPORT = /dev/ttyUSB0
 SRC = \
 	  src/ceda_print_a.asm	\
 	  src/ceda_print_c.c	\
+	  src/crt.c             \
 	  src/cursor.c          \
 	  src/delay.asm         \
 	  src/main.c 			\

src/main.c

@@ -1,30 +1,69 @@
 #include "ceda_print.h"
+#include "crt.h"
 #include "cursor.h"
 #include "delay.h"
 #include "io.h"
 
+static void wait(void) {
+    (void)io_in(0xA0);
+
+    for (;;) {
+        const uint8_t port_c = io_in(0x82);
+        if (port_c & 0x2)
+            break;
+    }
+}
+
 int main(void) {
     ceda_print("Hello world!");
 
-    // ceda_cls();
+    ceda_cls();
 
+#if 0
+    for (int i = 0; i < 80; ++i) {
+        cursor_setXY(i, 0);
+
+        // TODO(giomba): add vsync?
+        delay_loop(US_TO_LOOPS(10000ULL));
+    }
+#endif
+
+    int counter = 0;
+    __asm__("di");
+
+#if 0
     for (;;) {
-        for (int i = 0; i < 80; ++i) {
-            cursor_setXY(i, 0);
+        for (int i = 0; i < 50; ++i)
+            crt_waitNextFrame();
 
-            // TODO(giomba): add vsync?
-            delay_loop(US_TO_LOOPS(200000ULL));
+        // wait();
+        counter++;
+
+        int scratch = counter;
+        uint8_t digits[4];
+        digits[3] = scratch % 10;
+        scratch /= 10;
+        digits[2] = scratch % 10;
+        scratch /= 10;
+        digits[1] = scratch % 10;
+        scratch /= 10;
+        digits[0] = scratch % 10;
+
+        for (int i = 0; i < 4; ++i) {
+            digits[i] += '0';
+            *((char *)(0xd000 + i)) = digits[i];
         }
     }
+#endif
 
-    cursor_setStartRaster(5);
-    cursor_setEndRaster(10);
+    cursor_setXY(39, 10);
 
     for (;;) {
-        for (int i = 0; i < (16 - 1); ++i) {
-            cursor_setStartRaster(i);
-            cursor_setEndRaster(i + 1);
-            delay_loop(US_TO_LOOPS(200000UL));
+        for (int i = 0; i < 16; ++i) {
+            cursor_setStartRaster(0);
+            cursor_setEndRaster(i);
+            for (int j = 0; j < 8; ++j)
+                crt_waitNextFrame();
         }
     }