Epson 10020 - Manual (Page 80)

Note
MS-DOS provides several commands that make using
pathnames easy:
APPEND lets you set a search path for date files and
executable files so MS-DOS known where to find them
even if you don' specify the drive and directory.
PATH lets you specify a search path for commands and
programs files; so you don't have to type a full pathname
every time you want to run an application program or an
MS-DOS command.
SUBST lets you substitute drive letter for a directory
path, which is convenient if you frequently type long
pathnames.
See your MS-DOS Reference Manual for information on
these helpful commands.
Creating Directories
You use the MKDIR command to create directories in
MS-DOS. For example, to create a LEDGER directory under
your root directory, type the following and press Enter:
MKDIR \LEDGER
You can abbreviate the name of this command to MD. For
example, to create a SALES directory under the LEDGER
directory, type the following and press Enter:
MD \LEDGER\SALES
If you are currently in the LEDGER directory, you could create
the SALES subdirectory with this command:
MD SALES
Using MS-DOS With Your Computer 3-21