                             JOIN

The JOIN external command tells DOS to use a directory name on one disk as a 
shorthand way of referring to another disk drive. This allows several 
physcial disks or partitions (say, D:, E;, and F:) to be referred to as 
parts of another disk (say, C:).  The opposite of JOIN is SUBST.

    JOIN d1: [d2:]\directory
    JOIN d1: /D

d1 and d2 are disk drive letters.

<directory> is a directory on d2, and must be empty. It cannot be the
    current directory on d2. 

/D is used to delete the connection between d1 and the directory named on
    d2.

After JOINing, the disk drive letter d1: cannot be referenced until the JOIN 
has been deleted. JOIN won't work for disks on another computer in a network.
Trying to use BACKUP, REPLACE, RESTORE, or SUBST on a directory name defined 
by JOIN should be avoided.
