diff --git a/src/main.c b/src/main.c
index e098766..4cff308 100644
--- a/src/main.c
+++ b/src/main.c
@@ -32,12 +32,11 @@ typedef struct Frame
 
 static Frame frames[FRAMES] = {0};
 
-static void vga_program_init(PIO pio, uint sm, uint offset)
+static void vga_pixel_program_init(PIO pio, uint sm, uint offset)
 {
 	// magic definition of the called function?
 	pio_sm_config c = vga_free_run_program_get_default_config(offset);
 	sm_config_set_out_pins(&c, 22, 1);
-
 	pio_gpio_init(pio, 22);
 	pio_sm_set_consecutive_pindirs(pio, sm, 22, 1, true);
 
@@ -53,6 +52,20 @@ static void vga_program_init(PIO pio, uint sm, uint offset)
 	pio_sm_set_enabled(pio, sm, true);
 }
 
+static void vga_sync_program_init(PIO pio, uint sm, uint offset)
+{
+	pio_sm_config config = vga_sync_program_get_default_config(offset);
+	sm_config_set_out_pins(&config, 20, 2);
+	pio_gpio_init(pio, 20);
+	pio_sm_set_consecutive_pindirs(pio, sm, 20, 2, true);
+
+	pio_sm_init(pio, sm, offset, &config);
+
+	pio_sm_set_clkdiv_int_frac(pio, sm, 1, 0);
+
+	pio_sm_set_enabled(pio, sm, true);
+}
+
 int main()
 {
 	// main clock = VCO / divider1 / divider2 = 126MHz
@@ -60,12 +73,6 @@ int main()
 
 	stdio_init_all();
 
-#if 0
-  const uint LED_PIN = PICO_DEFAULT_LED_PIN;
-  gpio_init(LED_PIN);
-  gpio_set_dir(LED_PIN, GPIO_OUT);
-#endif
-
 	// "draw" an horizontal dotted line (?)
 	for (unsigned int c = 0; c < 20; c += 3)
 	{
@@ -76,18 +83,31 @@ int main()
 		frames[0].data[80 * 128 + 20 + c] = 0x99;
 	}
 
+	// PIO and state machines
 	PIO pio = pio0;
-	uint offset = pio_add_program(pio, &vga_free_run_program);
-	uint sm = pio_claim_unused_sm(pio, true);
-	vga_program_init(pio, sm, offset);
+
+	sleep_ms(5000);
+
+	// VGA pixel program
+	uint offset0 = pio_add_program(pio, &vga_free_run_program);
+	uint sm0 = pio_claim_unused_sm(pio, true);
+	printf("Starting VGA pixel machine on %u...\n", sm0);
+	vga_pixel_program_init(pio, sm0, offset0);
+
+	// VGA sync program
+	uint offset1 = pio_add_program(pio, &vga_sync_program);
+	uint sm1 = pio_claim_unused_sm(pio, true);
+	printf("Starting VGA sync machine on %u...\n", sm1);
+	vga_sync_program_init(pio, sm1, offset1);
 
 	printf("Welcome.\n");
 
+	// feed pixel program
 	while (true)
 	{
 		for (size_t i = 0; i < sizeof(frames[0].data); ++i)
 		{
-			pio_sm_put_blocking(pio, sm, frames[0].data[i]);
+			pio_sm_put_blocking(pio, sm0, frames[0].data[i]);
 		}
 		printf(".");
 		sleep_ms(1000);
diff --git a/src/vga.pio b/src/vga.pio
index e17f1df..823f81b 100644
--- a/src/vga.pio
+++ b/src/vga.pio
@@ -1,9 +1,19 @@
 .program vga_free_run
 
-
-entrypoint:
+entrypoint_vga_free_run:
     pull
 loop:
     out pins, 1 [2]
     jmp loop
 
+.program vga_sync
+
+entrypoint_vga_sync:
+loop:
+    set x, 31
+    mov osr, x
+    out pins, 1 [30]
+    set x, 0
+    mov osr, x
+    out pins, 1 [30]
+    jmp loop