diff --git a/assembler.pas b/assembler.pas
index 7b58a79..4a6da48 100644
--- a/assembler.pas
+++ b/assembler.pas
@@ -170,6 +170,7 @@ begin
     LP := 1;
     BP := 0;
     SP := 0;
+    EP := 0;
 
     //Begin the main loop
     repeat
@@ -264,7 +265,9 @@ begin
                         DatOrg := ExtractWord (2, Line, [' ']);
                         try
                             if Hex2Dec (DatOrg) <=$ffff then begin
+                                if BP > EP then EP := BP;
                                 BP := Hex2Dec (DatOrg);
+                                if BP < SP then SP := BP;
                             end
                             else ArgError;
                         except
@@ -434,7 +437,7 @@ begin
     if AllRefsResolved = false then halt (1);
 
     //Set the end pointer and reset the byte pointer to the start of the program
-    EP := BP;
+    if BP > EP then EP := BP;
     BP := SP;
 
     //Write the program file