1 CLS:CALL17001:PRINTSTRING$(40,32):PRINT@12,"Checksum 
Utility":CALL17006:PRINT:CLEAR999:MAXFILES=1:LINEINPUT"Filename : ";F$:OPENF$FORINPUTAS1
2 LINEINPUT#1,A$:L=LEN(A$):IFL=0THEN3ELSEFORX=1TOL:C=C+ASC(MID$(A$,X)):NEXTX
3 IFNOTEOF(1)THEN2ELSEPRINT"Checksum =";C:BEEP:CLOSE:MAXFILES=0:END