Date   : Tue, 28 Sep 1982 04:33:00-EDT
From   : Keith Petersen <W8SDZ@Mit-Mc>
Subject: directory checksums

CRCK.COM does that, gives a "cyclic redundancy check" rather than
simple checksum. CRC is less prone to errors than checksums.  The
source code, COM file and HEX file (in case you cannot FTP COM files)
is available on MIT-MC as AR24:CPM;CRCK 42BASM and CRCK 42BCOM.  The
HEX file is in AR13:CPM;CRCK 42BHEX.  The program prints the file
names as it reads each file, has optional command to write that output
to a disk file on the default drive.