diff -r f1b3bbf7c96b sys/src/games/blit/blit.c
--- a/sys/src/games/blit/blit.c	Tue Apr 11 02:26:39 2017 +0200
+++ b/sys/src/games/blit/blit.c	Fri Apr 14 15:57:12 2017 +0200
@@ -10,7 +10,6 @@
 
 int baud = 40000;
 int scale = 1;
-Rectangle picr;
 Image *tmp, *bg;
 Channel *keych, *uartrxch, *uarttxch;
 Mousectl *mc;
@@ -26,10 +25,6 @@
 static void
 screeninit(void)
 {
-	Point p;
-
-	p = divpt(addpt(screen->r.min, screen->r.max), 2);
-	picr = (Rectangle){subpt(p, Pt(scale * SX/2, scale * SY/2)), addpt(p, Pt(scale * SX/2, scale * SY/2))};
 	if(tmp != nil) freeimage(tmp);
 	tmp = allocimage(display, Rect(0, 0, scale * SX, scale > 1 ? 1 : scale * SY), CHAN1(CMap, 1), scale > 1, 0);
 	if(bg != nil) freeimage(bg);
@@ -56,9 +51,9 @@
 		screeninit();
 	}
 	while(nbrecv(mc->c, &m) > 0){
-		if(ptinrect(m.xy, picr)){
-			mousex = picr.max.x - m.xy.x - 1;
-			mousey = picr.max.y - m.xy.y - 1;
+		if(ptinrect(m.xy, screen->r)){
+			mousex = screen->r.max.x - m.xy.x - 1;
+			mousey = screen->r.max.y - m.xy.y - 1;
 		}
 		n = m.buttons >> 2 & 1 | m.buttons & 2 | m.buttons << 2 & 4;
 		if(n != mousebut){
@@ -88,10 +83,10 @@
 
 	loadimage(tmp, r, pic+o, Dy(r)*(SX/8));
 	if(realcolors){
-		draw(screen, rectaddpt(r, picr.min), colfg, nil, r.min);
-		draw(screen, rectaddpt(r, picr.min), colbg, tmp, r.min);
+		draw(screen, rectaddpt(r, screen->r.min), colfg, nil, r.min);
+		draw(screen, rectaddpt(r, screen->r.min), colbg, tmp, r.min);
 	}else
-		draw(screen, rectaddpt(r, picr.min), tmp, nil, r.min);
+		draw(screen, rectaddpt(r, screen->r.min), tmp, nil, r.min);
 	updated = Rect(SX, SY, 0, 0);
 	flushimage(display, 1);
 }
@@ -157,12 +152,13 @@
 void
 threadmain(int argc, char **argv)
 {
-	int n;
+	int n, ms;
 	static Cursor blank;
 	char *telnet;
 	char *p;
 	extern int diag;
 	
+	ms = 0;
 	telnet = nil;
 	ARGBEGIN{
 	case 'b':
@@ -184,6 +180,9 @@
 	case 'd':
 		diag++;
 		break;
+	case 'm':
+		ms++;
+		break;
 	default: usage();
 	}ARGEND;
 	if(argc != 0) usage();
@@ -201,7 +200,8 @@
 	mc = initmouse(nil, screen);
 	if(mc == nil)
 		sysfatal("initmouse: %r");
-	setcursor(mc, &blank);
+	if(ms == 0)
+		setcursor(mc, &blank);
 
 	cpureset();
 	for(;;){