Epson EQUITY 386SX/16 PLUS - Manual (Page 66)

Using a Single Diskette Drive System
MS-DOS expects the computer to have at least two diskette
drives and displays prompts and messages accordingly.
Usually, MS-DOS recognizes the first diskette drive (the top
drive) as A and a second diskette drive as B. If you have only
one diskette drive, MS-DOS can treat it as both A and B when
you need to perform operations that normally require two
diskette drives.
For example, if you enter a command to copy data from A
to B, MS-DOS copies the data from the first diskette you place
in the drive (which would be 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 copying is complete, you see a prompt to
insert the original diskette (A).
Because you may often swap diskettes this way, it is
important to remember which diskette is which. It is also a
good idea to write-protect your original diskette. See “Write-
protecting Diskettes,” above.
If you have a hard disk and one diskette drive, 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 or from diskettes.
However, if you have only one diskette drive and no hard
disk, you need to use that drive to load the operating system
as well as any application program you are using. First, insert
the operating system diskette (the Startup diskette, for
example) in drive A and load the operating system; this
copies it to the computer’s memory (RAM) so you do not
need to leave the system diskette in the drive. Then remove
the system diskette and insert your application program
diskette to load that data into memory, too. See your
application program manual for detailed instructions.
3-14 Using Your Computer