diff --git a/definitions.asm b/definitions.asm
index 9594628..2508f10 100644
--- a/definitions.asm
+++ b/definitions.asm
@@ -10,8 +10,8 @@ PMGraph =  $0800  ; real PM start = $0b00
 
 
 ; Generated tables
-linetableL = $0b00 - screenHeight*2
-linetableH = $0b00 - screenHeight
+linetableL = $0b00 - (screenHeight+1)*2
+linetableH = $0b00 - (screenHeight+1)
 
 display = $1010 ;screen takes $2K due to clearing routine
 
diff --git a/scorch.asm b/scorch.asm
index 3dac628..c6d2174 100644
--- a/scorch.asm
+++ b/scorch.asm
@@ -200,7 +200,7 @@ FirstSTART
       sta (modify),y
       adw temp #40
       iny
-      cpy #screenheight
+      cpy #screenheight+1
     bne @-
 
 
@@ -1362,7 +1362,7 @@ UsageLoop
     sta temp2+1
 	
     cpw RandBoundaryLow temp2
-    bcs RandomizeForce
+    seq:bcs RandomizeForce
 
     cpw RandBoundaryHigh temp2
     bcc RandomizeForce
diff --git a/scorch.xex b/scorch.xex
index 3381abf..2e625ff 100644
Binary files a/scorch.xex and b/scorch.xex differ