Epson Apex 20020 - Manual (Page 116)

If you need to change anything in the AUTOEXEC.BAT file
later, you can use the same procedure to modify the commands.
See your MS-DOS Reference Manual for instructions.
Using HDCACHE for the Hard Disk
You can use the MS-DOS program HDCACHE to enhance the
performance of your hard disk. This program makes the hard
disk work more efficiently by storing data requests in a reserved
part of memory. See your MS-DOS Reference Manual for more
information.