Kreisen 3 8 6 X / X E - Manual (Page 62)

Note
You must format new diskettes before you can use them
with an operating system. Formatting erases all the data on
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 following tables
summarize the possiblities and limitations.
5¼-inch drive/diskette compatibility
Drive type Diskette types it can read from and write to
360KB 180KB, or 360KB
1.2MB 180KB, 360KB. or 1.2MB
3½-inch drive/diskette compatibility
Drive type
720KB
1.44MB
Diskette types it can read from and write to
720KB
720KB, or 1.44MB
Warning
If you write to a 360KB (or 180KB) 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.
Using Your Computer 3-9