Explanation of the DISKCOMP command. It is EXTERNAL.

This command will compare the contents of two different disks,
and tell you if and what kind of differences there are between
the two disks.

Example:
       To compare only the contents of one side, even though 
       the disks and drives are made for double sided, of two
       disks, one in drive A and the other in B you type this:
            diskcomp a: b: /1