CRCCHECK Written 1996 by William H. Decorie

The purpose of this program is to scan the files in the current directory
and calculate their 32-bit CRC.  This CRC value is then compared against a
list of previously calculated CRCs stored in a special file in the directory.

This program isn't very fancy, or for that matter very useful as is.
However, it does provide the basis for a much more powerful program.  Also,
it's good for showing how to calculate a 32-bit CRC in Turbo Pascal.  It
demonstrates how to use 32-bit instructions in Turbo Pascal.  There is also
a routine which determines whether or not the machine is capable of running
32-bit instructions.

Why would you want to check the CRC of files?  Two answers jump immediately
to my mind.  The first is to protect against viruses.  This program does
not scan for the presence of viruses; rather, it can detect if a file has
been infected (even though the size, time & date in the directory listing
hasn't changed, doesn't mean an executable isn't infected).  Second, data
corruption, especially on compressed drives.  A few years ago I lost a lot
of data on a compressed drive (this was back when hard drives cost $$$),
even though outwardly everything appeared OK.  Had I run a CRC check on my
data, I would have been able to catch the problem earlier.
