diff --git a/scorch.asm b/scorch.asm
index 9572160..7ab22b5 100644
--- a/scorch.asm
+++ b/scorch.asm
@@ -26,7 +26,8 @@
 ;---------------------------------------------------
     icl 'definitions.asm'
 ;---------------------------------------------------
-    .zpvar DliColorBack		.byte = $62
+FirstZpageVariable = $62
+    .zpvar DliColorBack		.byte = FirstZpageVariable
     .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
@@ -230,6 +231,12 @@ FirstSTART
 	  dey
 	bpl @-
 	
+	; one time zero variables in RAM (zero page)
+	ldy #FirstZpageVariable
+@	sta $0000,y
+	iny
+	bne @-
+	
 	; initialize variables in RAM (non zero page)
 	ldy #initialvaluesCount-1
 @	  lda initialvaluesStart,y
diff --git a/scorch.bin b/scorch.bin
index 62f1bac..070d2f8 100644
Binary files a/scorch.bin and b/scorch.bin differ
diff --git a/scorch.xex b/scorch.xex
index 2765f57..7bc3ef3 100644
Binary files a/scorch.xex and b/scorch.xex differ