Epson 20 - Manual (Page 68)

Note
You must format new diskettes before you can use them with an
operating system, Formatting erases all the data an a diskette and
prepares it to receive- new data; so be sure to format only new
blank diskettes or diskettes that contain data you
want to erase,
‘See Chapter 5 for instructions on formatting diskettes.
Drive and diskette incompatibilities
Because of the size difference, you cannot use 3½-inch diskettes in a
5¼-inch drive or vice versa. There are also certain limitations on
using diskettes that are the same size as the drive but have different
capacities. The tables below summarize the possibilities and
limitations.
5¼-inch drive/diskette compatibility
Drive type Diskette types it can read from and write to
360KB 160KB, 180KB, 320KB, or 360KB
1.2MB 160KB, 180KB, 320KB, 360KB, or 1.2MB
WARNING
If you write to a 360KB (or 160KB, 180KB, or 320KB) diskette
while it is in
a 1.2MB
drive, you may not be able to read it or write
to it in a 360KB drive later.
3½-inch drive/diskette compatibility
Drive type Diskette types it can read from and write to
720KB 720KB
1.44MB 720KB, 1.44MB
Because of these incompatibilities, you should indicate the density
and diskette type when you label your diskettes. (Usually this
information appears on the manufacturer’s label.)
Using the Equity 386 4-11