CLS
DEFINT A-Z
KOM$ = ENVIRON$("COMSPEC")
OPEN KOM$ FOR BINARY AS #1
 L& = LOF(1)
 Fragments& = L& \ 10000
 Restbytes = L& - Fragments& * 10000
 FOR f& = 0 TO Fragments& - 1
  frag$ = SPACE$(10000)
  GET #1, , frag$
  FOR p = 1 TO LEN(frag$)
   c& = c& + ASC(MID$(frag$, p, 1))
  NEXT p
 NEXT f&
 IF Restbytes > 0 THEN
  frag$ = SPACE$(Restbytes)
  GET #1, , frag$
  FOR p = 1 TO LEN(frag$)
   c& = c& + ASC(MID$(frag$, p, 1))
  NEXT p
 END IF
CLOSE #1
PRINT "Ergebnis fr "; KOM$
PRINT "------------------------------"
PRINT "L„nge in Bytes:"; L&
PRINT "Checksumme:    "; c&
PRINT "------------------------------"
IF c& = 10679540 AND L& = 106310 THEN
 PRINT "4DOS Version 4.00"
ELSEIF c& = 6191082 AND L& = 56879 THEN
 PRINT "Novell DOS 7"
ELSEIF c& = 5172664 AND L& = 57351 THEN
 PRINT "MS-DOS 6.20"
ELSEIF c& = 5001845 AND L& = 55591 THEN
 PRINT "MS-DOS 6.0"
ELSEIF c& = 4508806 AND L& = 50031 THEN
 PRINT "MS-DOS 5.0"
' hier CHKCOM aktualisieren, neuen
' ELSEIF-Block einfgen!
ELSE
 COLOR 4, 0: BEEP
 PRINT "Unbekannte DOS-Version oder Ver„nderung durch Virus!": COLOR 7, 0
END IF
SYSTEM