Epson 10020 - Manual (Page 56)

Chapter 1 describes how to use DISKCOPY to copy your
MS-DOS and Reference diskettes. To make backups of other
diskettes, use the DISKCOPY command or the MENU
program. See Chapter 3 for more instructions on using
DISKCOPY and MENU.
If you have the Apex 100\20, it is best to put most of the
programs and data files you use regularly on the hard disk. Keep
backup copies of all your program files on diskettes, however,
and regularly copy important data files to diskettes as well. For
more information, see “Backing Up Data” in Chapter 3 and
check your MS-DOS Reference Manual.
Using a Single Diskette Drive
The operating system expects the computer to have at least
two diskette drives, and it displays prompts and messages
accordingly. If your system has only one diskette drive,
MS-DOS treats your one drive like two logical drives. This
helps you perform operations that normally require two diskette
drives.
Usually, MS-DOS recognizes the first diskette drive (the top
drive) as drive A and a second diskette drive as B. If you have
only one diskette drive, MS-DOS recognizes it as both A
and B.
For example, if you give a command to copy from A to B,
MS-DOS copies data from the first diskette you place in the
drive (A) to the computer’s memory. Then MS-DOS prompts
you to insert another diskette (for drive B) and copies the
data from memory to the new diskette. When the copying is
complete, you see a prompt to insert the original diskette (for
drive A).
Because you may often swap diskettes this way, it is important
to remember which diskette is which. One way to avoid
accidentally losing data is to hold the diskette for one drive in
your left hand and the diskette for the other in your right. It is
also a good idea to write-protect your original diskette.
Using Your Computer 2-15