Epson Apex 20020 - Manual (Page 76)

The Default Drive
At any given time, MS-DOS considers one disk drive to be the
default drive. The default drive is the one on which MS-DOS
executes your next command, unless you tell it to do otherwise.
For example, if the default drive is C, and you issue the DIR
(directory) command, MS-DOS lists the files stored on drive
C. If the default drive is A and you type
WP
and press Enter,
MS-DOS looks on the diskette in drive A for a file called WP
and executes it.
The MS-DOS command prompt tells you which drive is the
current default. The command prompt consists of the drive
letter followed by a greater-than symbol, "<". (Depending on
how your system has been set up, the command prompt may
also include additional information.) Thus, when you see A>
displayed on your screen, you know that the default drive is A.
The command prompt also lets you know that MS-DOS is
ready to receive a command from you.
If you need to access a file or program on another drive, you
can either change the default drive or specify the other drive
when you give the command.
Changing the Default Drive
To change the default drive, type the letter of the drive you
want to change to, followed by a colon. Then press
Enter. For
example, to change the default from A to C, type the following
and press Enter:
c :
MS-DOS acknowledges the change by displaying the command
prompt
C
: \>. Changing to a new drive is also called logging
onto that drive.