diff --git a/README.md b/README.md
index 383a8b0..3ae2372 100644
--- a/README.md
+++ b/README.md
@@ -1097,47 +1097,49 @@ See `eightballvm.h` for technical details.
 ## Prime Number Sieve
 
 Here is the well-known Sieve of Eratosthenes algorithm for finding prime numbers, written in EightBall:
+```
+ ' Sieve of Eratosthenes
 
-    ' Sieve of Eratosthenes                                                         
-                                                                                
-    ' Globals                                                                       
-    byte nr = 10                                                                    
-    word n = nr * nr                                                                
-    byte A[100] = 1 ' Has to be a literal                                                                   
-                                                                                
-    pr.msg "Sieve of Eratosthenes ..."; pr.nl                                       
-    call doall()                                                                    
-    end                                                                             
-                                                                                
-    sub doall()                                                                     
-      call sieve()                                                                  
-      call printresults()                                                           
-    endsub                                                                       
-                                                                                
-    sub sieve()                                                                     
-      word i = 0; word j = 0                                                        
-      for i = 2 : (nr - 1)                                                          
-        if A[i]                                                                     
-          j = i * i                                                                 
-          while (j < n)                                                             
-            A[j] = 0                                                                
-            j = j + i                                                               
-          endwhile                                                                  
-        endif                                                                       
-      endfor                                                                        
-    endsub                                                                        
-                                                                                
-    sub printresults()                                                              
-      word i = 0                                                                    
-      for i = 2 : (n - 1)                                                           
-        if A[i]                                                                     
-          if i > 2                                                                  
-            pr.msg ", "                                                             
-          endif                                                                     
-          pr.dec i                                                                  
-        endif                                                                       
-      endfor                                                                        
-      pr.msg "."                                                                    
-    endsub                                                                        
-                                                                                
-  
+byte A[20*20] = 1
+call doall(20, A)
+end
+
+sub doall(word nr, byte array[])
+  word n = nr * nr
+  pr.msg "Sieve of Eratosthenes ..."
+  pr.msg "nr is "; pr.dec nr; pr.nl
+  call sieve(n, nr, array)
+  call printresults(n, array)
+  return 0
+endsub
+
+sub sieve(word n, word nr, byte AA[])
+  pr.msg "Sieve"
+  word i = 0; word j = 0
+  for i = 2 : (nr - 1)
+    if AA[i]
+      j = i * i
+      while (j < n)
+        AA[j] = 0
+        j = j + i
+      endwhile
+    endif
+  endfor
+  return 0
+endsub
+
+sub printresults(word n, byte AA[])
+  word i = 0
+  for i = 2 : (n - 1)
+    if AA[i]
+      if i > 2
+        pr.msg ", "
+      endif
+      pr.dec i
+    endif
+  endfor
+  pr.msg "."
+  pr.nl
+  return 0
+endsub
+```