>L.

  480 CLS:PROCgrid:F%=0

  520 USED=TRUE:IF W%>D%:M%=W% ELSE M%=D%

 1560 O%=OPENOUT(G$):PRINT#O%,W%,D%,F%:PROCmid

 1580 VDU31,X%,Y%:PROCosbyte:IF POINT(X%*32+8,956-Y%*32)<>3:U%=U%+255

 1590 PRINT#O%,U%:NEXT:NEXT

 1660 O%=OPENIN(G$):INPUT#O%,W%,H%,F%:PROCgrid

 1680 INPUT#O%,U%:COLOUR3:IF U%>255:U%=U%-255:COLOUR2

 1690 VDU31,X%,Y%,U%:NEXT:NEXT

>*SPOOL

