@@ -28,13 +28,12 @@ static Uint32 palette_mono[] = {

 static void

 screen_write(UxnScreen *p, Layer *layer, Uint16 x, Uint16 y, Uint8 color)

 {

-	Uint32 i;

-	if(x > p->width || y > p->height)

-		return;

-	i = x + y * p->width;

-	if(color != layer->pixels[i]) {

-		layer->pixels[i] = color;

-		layer->changed = 1;

+	if(x < p->width && y < p->height) {

+		Uint32 i = x + y * p->width;

+		if(color != layer->pixels[i]) {

+			layer->pixels[i] = color;

+			layer->changed = 1;

+		}

 	}

 }

@@ -189,7 +188,7 @@ screen_deo(Uint8 *ram, Uint8 *d, Uint8 port)

 		n = d[0x6] >> 4;

 		dx = (d[0x6] & 0x01) << 3;

 		dy = (d[0x6] & 0x02) << 2;

-		if(addr > 0xfff0)

+		if(addr > 0x10000 - ((n + 1) << (3 + twobpp)))

 			return;

 		for(i = 0; i <= n; i++) {

 			if(!(d[0xf] & 0xf))