diff --git a/UNKNOWN/createImages b/UNKNOWN/createImages
index 82737a9ed1061ef698bc57b39f7c3daa07732cca..7de143027d7ee57b2534f724e3c9185df68351cb 100755
--- a/UNKNOWN/createImages
+++ b/UNKNOWN/createImages
@@ -51,6 +51,7 @@ digitFile[7]='digit-7.png'
 digitFile[8]='digit-8.png'
 digitFile[9]='digit-9.png'
 digitFile[10]='digit-E.png'
+digitFile[11]=$emptyCanvas
 
 digitPos[1]='+273+190'
 digitPos[2]='+319+190'
@@ -71,6 +72,7 @@ NUM2CHAR[7]='7'
 NUM2CHAR[8]='8'
 NUM2CHAR[9]='9'
 NUM2CHAR[10]='E'
+NUM2CHAR[11]='_'
 
 for ((FNb=1; FNb<=MAX_FILES; FNb++)); do
 
@@ -78,7 +80,7 @@ value=""
 DPR=$((RANDOM % $NUMBER_OF_DIGITS + 1)) # random dot position (1..$NUMBER_OF_DIGITS)
 for (( i=1; i<=$MAX_DIGITS; i++ )); do
   if (( $i <= $NUMBER_OF_DIGITS )); then
-    R=$((RANDOM % 11)) # random digit number (0..10='0'..'E')
+    R=$((RANDOM % 12)) # random digit number (0..11='0'..'_')
     eval DIGIT$i=${digitFile[R]}
     value+="${NUM2CHAR[R]}"
     if [ $DPR == $i ]; then
diff --git a/UNKNOWN/dot.png b/UNKNOWN/dot.png
index 24dd38436ccb26a51fa7ebe4478e5699fbc8cef4..beaade4ab34f32d047f02d862779578b1a2541c8 100644
Binary files a/UNKNOWN/dot.png and b/UNKNOWN/dot.png differ