


                             ---------------------
                             ZAPCHK - What It Does
                             ---------------------

         ZAPCHK is a quick and dirty utility that patches MSDOS
         CHKDSK.EXE v6.2x to remove these SCANDISK advertising
         messages:


         "Instead of using CHKDSK, try using SCANDISK.  SCANDISK can
         reliably detect and fix a much wider range of disk problems.
         For more information, type HELP SCANDISK from the command
         prompt."


         There are two advertising messages posted, depending upon how
         CHKDSK is started.  CHKDSK /F produces a slightly different
         method, and asks the user for a (Y/N) answer to proceed.
         This is irritating, at the least.


                             ----------------------
                             ZAPCHK - How To Use It
                             ----------------------

         CHKDSK.EXE *must* be first unpacked with PKLITE before it can
         be patched.

         (1) Copy CHKDSK.EXE to a temporary working directory.
         (2) Issue PKLITE -x CHKDSK.EXE to unpack it.
         (3) Run ZAPCHK against CHKDSK.EXE in the default directory.
         (4) Issue PKLITE -o CHKDSK.EXE to repack it again.


                             ---------------------
                             ZAPCHK - How It Works
                             ---------------------

         This utility prevents these two messages from being called
         during the operation of CHKDSK by NOP'ing the calls to the
         message display.  No other logical operation of CHKDSK has
         been changed.

         Borland C v3.1 source code is included.


                            ------------------------
                            ZAPCHK - Error Detection
                            ------------------------

         ZAPCHK does a 17 byte signature compare within CHKDSK.EXE.
         All 17 bytes must match, or the patch operation is aborted.

         ZAPCHK also performs a CRC-16 calculation on the CHKDSK.EXE
         file. It determines the file version, and whether or not it
         has been uncompressed with PKLITE.  Messages are posted
         accordingly.


                             ---------------------
                             ZAPCHK - Who To Thank
                             ---------------------

         Bruce Gavin
         Online Reference BBS
         CIS    : [70137,3244]
         Voice  : (916) 988-7551
         FAX/BBS: (916) 988-0920
