diff --git a/grafproc.asm b/grafproc.asm
index dcb1b89..b9fd115 100644
--- a/grafproc.asm
+++ b/grafproc.asm
@@ -224,6 +224,8 @@ PutPixelinDraw
     bit drawFunction
     bpl @+
     inw LineLength
+	bit Vdebug
+	bmi MeasureVisualisation
     jmp ContinueDraw  ; was `bne` - not good, because LineLength starts from $ffff
 @
     bvc @+
@@ -271,6 +273,7 @@ CheckCollisionDraw
 StopHitChecking
     jmp ContinueDraw
 @
+MeasureVisualisation
     jsr plot   
 
 ContinueDraw
diff --git a/scorch.asm b/scorch.asm
index 82e9658..efe486a 100644
--- a/scorch.asm
+++ b/scorch.asm
@@ -27,12 +27,13 @@
     icl 'definitions.asm'
 ;---------------------------------------------------
 
-FirstZpageVariable = $5A
+FirstZpageVariable = $59
     .zpvar DliColorBack		.byte = FirstZpageVariable
 	.zpvar GradientNr		.byte
 	.zpvar GradientColors	.word
 	.zpvar WindChangeInRound	.byte	; wind change after each turn (not round only) flag - (0 - round only, >0 - each turn)
 	.zpvar JoystickNumber	.byte
+	.zpvar Vdebug			.byte ; "visual debug" flag ($00 - off, $ff - on)
     .zpvar xdraw            .word ;= $64 ;variable X for plot
     .zpvar ydraw            .word ;variable Y for plot (like in Atari Basic - Y=0 in upper right corner of the screen)
     .zpvar xbyte            .word
diff --git a/scorch.bin b/scorch.bin
index 16c7f87..4d65866 100644
Binary files a/scorch.bin and b/scorch.bin differ
diff --git a/scorch.xex b/scorch.xex
index 21236d1..d2a8fff 100644
Binary files a/scorch.xex and b/scorch.xex differ
diff --git a/weapons.asm b/weapons.asm
index 3e091af..bdf9023 100644
--- a/weapons.asm
+++ b/weapons.asm
@@ -1185,6 +1185,13 @@ jumpFromStick
     cmp #@kbcode._S  ; $3e  ; S
     jeq pressedS
 	.IF TARGET = 800
+	cmp #38	; /
+	bne NoVdebugSwitch
+	lda Vdebug
+	eor #$ff
+	sta Vdebug
+	jmp ReleaseAndLoop
+NoVdebugSwitch	
 	cmp #61	; G
 	bne EndKeys
 	jsr SelectNextGradient
@@ -1789,10 +1796,16 @@ SkipCollisionCheck
     mwa ytraj+1 ydraw
 	
 	bit TestFlightFlag
-	bvs NoUnPlot
-    lda tracerflag
+	bvc NoTestFlight
+	bit Vdebug
+	bpl NoTestFlight
+	jsr WaitOneFrame	; visualize AI targeting
+	jmp YesUnPlot
+NoTestFlight
+	lda tracerflag
     bne NoUnPlot
-
+	
+YesUnPlot
     jsr UnPlot
 
 NoUnPlot