diff --git a/etc/screen.bounds.tal b/etc/screen.bounds.tal
index 701edb1..dd8dacb 100644
--- a/etc/screen.bounds.tal
+++ b/etc/screen.bounds.tal
@@ -9,6 +9,7 @@
 	#286c .System/g DEO2
 	#2358 .System/b DEO2
 	;on-mouse .Mouse/vector DEO2
+	<draw-guide>
 	BRK
 
 @on-mouse ( -> )
@@ -16,6 +17,7 @@
 	#0000 DUP2 .Screen/x DEO2
 	.Screen/y DEO2
 	#80 .Screen/pixel DEO
+	<draw-guide>
 	( | cursor )
 	#41 ;cursor-icn <update-cursor>
 	( | draw portrait )
@@ -47,6 +49,44 @@
 	#05 .Screen/sprite DEOk DEOk DEOk DEO
 	JMP2r
 
+@<draw-circle> ( color -- )
+	#01 .Screen/auto DEO
+	;circle-chr .Screen/addr DEO2
+	DUP .Screen/sprite DEO
+	DUP #10 ORA .Screen/sprite DEO
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	DUP #20 ORA .Screen/sprite DEO
+	#30 ORA .Screen/sprite DEO
+	JMP2r
+
+@<draw-guide> ( -- )
+	#0000 DUP2 .Screen/x DEO2 .Screen/y DEO2
+	#f2 .Screen/auto DEO
+	;guide-icn .Screen/addr DEO2
+	#1000
+	&l ( -- ) 
+		#01 .Screen/sprite DEO
+		INC GTHk ?&l 
+	POP2
+	( | circles )
+	#0010 DUP2 .Screen/x DEO2 .Screen/y DEO2
+	#02 <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#82 <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#05 <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#85 <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#03 <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#83 <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#0a <draw-circle>
+	.Screen/y DEI2k #0008 ADD2 ROT DEO2
+	#8a <draw-circle>
+	JMP2r
+
 @<update-cursor> ( color addr* -- )
 	[ LIT2 00 -Screen/auto ] DEO
 	;fill-icn .Screen/addr DEO2
@@ -61,6 +101,8 @@
 	.Screen/sprite DEO
 	JMP2r
 
+@guide-icn [ 0101 0101 0101 01ff ]
+
 @fill-icn [ ffff ffff ffff ffff ]
 
 @cursor-icn [ 80c0 e0f0 f8e0 1000 ]
@@ -93,3 +135,7 @@
 	4142 4448 5020 1f00 0000 0000 0000 ff00
 	0000 0000 0000 ff00 8242 2212 0a04 f800 ]
 
+@circle-chr [
+	071f 3c70 60e3 c7c7 0000 030f 1f1f 3f3f ]
+
+
diff --git a/src/devices/screen.c b/src/devices/screen.c
index c9c0c10..f5d7758 100644
--- a/src/devices/screen.c
+++ b/src/devices/screen.c
@@ -60,8 +60,8 @@ screen_2bpp(Uint8 *layer, Uint8 *ram, Uint16 addr, Uint16 x1, Uint16 y1, Uint16
 {
 	int width = uxn_screen.width, height = uxn_screen.height, opaque = (color % 5);
 	Uint8 *ch1 = &ram[addr], *ch2 = ch1 + 8;
-	Uint16 y, ymod = (fy < 0 ? 8 : 0), ymax = y1 + ymod + fy * 8;
-	Uint16 x, xmod = (fx > 0 ? 8 : 0), xmax = x1 + xmod - fx * 8;
+	Uint16 y, ymod = (fy < 0 ? 7 : 0), ymax = y1 + ymod + fy * 8;
+	Uint16 x, xmod = (fx > 0 ? 7 : 0), xmax = x1 + xmod - fx * 8;
 	for(y = y1 + ymod; y != ymax; y += fy) {
 		Uint16 c = *ch1++ | (*ch2++ << 8);
 		for(x = x1 + xmod; x != xmax; x -= fx, c >>= 1) {
@@ -77,8 +77,8 @@ screen_1bpp(Uint8 *layer, Uint8 *ram, Uint16 addr, Uint16 x1, Uint16 y1, Uint16
 {
 	int width = uxn_screen.width, height = uxn_screen.height, opaque = (color % 5);
 	Uint8 *ch1 = &ram[addr];
-	Uint16 y, ymod = (fy < 0 ? 8 : 0), ymax = y1 + ymod + fy * 8;
-	Uint16 x, xmod = (fx > 0 ? 8 : 0), xmax = x1 + xmod - fx * 8;
+	Uint16 y, ymod = (fy < 0 ? 7 : 0), ymax = y1 + ymod + fy * 8;
+	Uint16 x, xmod = (fx > 0 ? 7 : 0), xmax = x1 + xmod - fx * 8;
 	for(y = y1 + ymod; y != ymax; y += fy) {
 		Uint16 c = *ch1++;
 		for(x = x1 + xmod; x != xmax; x -= fx, c >>= 1) {