diff --git a/chr6.c b/chr6.c
index 3b14734..efac956 100644
--- a/chr6.c
+++ b/chr6.c
@@ -69,8 +69,6 @@ dispt(Point* a, Point* b)
 	return ((b->x - a->x) * (b->x - a->x)) + ((b->y - a->y) * (b->y - a->y));
 }
 
-/* Draw */
-
 void
 pixel(uint32_t* dst, Point p, int c)
 {
@@ -88,7 +86,7 @@ draw(uint32_t* dst, int id, int color)
 	int ti = id / 64;
 	int px = (ti / (HOR * VER)) * (8 * HOR);
 	int tx = (ti % HOR) * 8;
-	int ty = ((ti / HOR) * 8) % 128;
+	int ty = ((ti / HOR) * 8);
 	int odd = (ti + (ti / HOR + 2)) % 2 == 0;
 	Point p;
 	p.x = px + tx + (id % 8);
@@ -115,14 +113,12 @@ redraw(uint32_t* dst)
 	SDL_RenderPresent(gRenderer);
 }
 
-/* Chr */
-
 void
 write(int tx, int ty, int px, int py, int color)
 {
 	int id = tx + ty * HOR;
-	int row = py + id * VER;
-	if(id > HOR * VER)
+	int row = py + (id * 16);
+	if(row > SZ - 8)
 		return;
 	if(color == 0) {
 		buffer[row] &= ~(1UL << (7 - px));
@@ -144,16 +140,9 @@ edit(int x, int y, int color)
 {
 	if(x < 0 || y < 0 || x > 8 * HOR || y > 8 * VER)
 		return;
-	write(
-	    x / (8),
-	    y / (8),
-	    x % 8,
-	    y % 8,
-	    color);
+	write(x / 8, y / 8, x % 8, y % 8, color);
 }
 
-/* Brush */
-
 int
 patt(int x, int y, int mode, int size)
 {
@@ -436,16 +425,12 @@ main(int argc, char** argv)
 	if(!init())
 		return error("SDL", "failure");
 
-	/* IO */
-
 	if(argc > 1)
 		load(argv[1]);
 	else
 		create();
 	update(&brush);
 
-	/* main loop */
-
 	while(1) {
 		int tick = SDL_GetTicks();
 		SDL_Event event;