Would be easier to debug if you showed source code. 2 things might be wrong. 1: If you're using BGFILL then it should be BGFILL 2,0,0,25,15 2: If you're using BGPUT in a FOR loop, then. FOR X=0 TO 25 FOR X=0 TO 15 BGPUT 2,X,Y,91 NEXT NEXT