diff --git a/projects/software/supervisor.tal b/projects/software/supervisor.tal
index 31c1b27..3fa5910 100644
--- a/projects/software/supervisor.tal
+++ b/projects/software/supervisor.tal
@@ -36,14 +36,13 @@
 
 @center
 	&x $2 &y $2
-
 @modal
 	&x $2 &y $2
 
 ( init )
 
 |0100 ( -> )
-
+	
 	.Screen/width DEI2 2// 
 		DUP2 .center/x STZ2
 		MODALW #31 SFT2 -- .modal/x STZ2
@@ -51,11 +50,17 @@
 		DUP2 .center/y STZ2
 		MODALH #31 SFT2 -- .modal/y STZ2
 
+	( vectors )
+	;on-error .System/vector DEO2
+	;on-frame .Screen/vector DEO2
+
+BRK
+
+@on-frame ( -> )
+
 	;draw-cross JSR2
 	;draw-stacks JSR2
 
-	EADDR LDA2 #0000 !! ;on-error JCN2
-
 BRK
 
 @on-error ( -> )
diff --git a/src/devices/system.c b/src/devices/system.c
index 9deaf41..aaf198c 100644
--- a/src/devices/system.c
+++ b/src/devices/system.c
@@ -31,7 +31,7 @@ uxn_halt(Uxn *u, Uint8 error, Uint16 addr)
 	Uint16 vec = d->vector;
 	DEVPOKE16(0x4, addr);
 	d->dat[0x6] = error;
-	uxn_eval(&supervisor, PAGE_PROGRAM);
+	uxn_eval(&supervisor, supervisor.dev[0].vector);
 	if(vec) {
 		d->vector = 0; /* need to rearm to run System/vector again */
 		if(error != 2) /* working stack overflow has special treatment */
diff --git a/src/uxnemu.c b/src/uxnemu.c
index d170343..34e35a9 100644
--- a/src/uxnemu.c
+++ b/src/uxnemu.c
@@ -309,6 +309,8 @@ start(Uxn *u, char *rom)
 	uxn_port(&supervisor, 0x1, nil_dei, console_deo);
 	uxn_port(&supervisor, 0x2, screen_dei, screen_deo);
 
+	uxn_eval(&supervisor, PAGE_PROGRAM);
+
 	if(!uxn_eval(u, PAGE_PROGRAM))
 		return error("Boot", "Failed to start rom.");
 
@@ -485,7 +487,7 @@ run(Uxn *u)
 				console_input(u, event.cbutton.button);
 		}
 		if(devsystem->dat[0xe])
-			uxn_eval(&supervisor, PAGE_PROGRAM);
+			uxn_eval(&supervisor, supervisor.dev[2].vector);
 		uxn_eval(u, devscreen->vector);
 		if(uxn_screen.fg.changed || uxn_screen.bg.changed || devsystem->dat[0xe])
 			redraw();