Kreisen 3 8 6 X / X E - Manual (Page 69)

Chapter 1 describes how to use DISKCOPY to copy your
MS-DOS diskette. For more detailed information to make
backups of other diskettes, refer to Chapter 4 “Using MS-DOS
with your computer”.
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.
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 the computer has only one diskette drive, MS-DOS
treats the 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 the second diskette drive as drive 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 diskette you place in the single
drive (A) to the computer’s memory. Then MS-DOS
automatically prompts you to insert another diskette in the
same drive, which it now identifies as drive B. It copies the
data from memory to the new diskette. When the copying is
complete, MS-DOS identifies the drive as drive A again, and
you see a prompt to insert the original diskette into drive A.
You can load the operating system and application programs
from the hard disk, create and store your data there, and use
the diskette drive just for copying data to and from diskettes.
3-16 Using Your Computer