Apple Macintosh PowerBook 150 - Manual (Page 17)

What you need
Just as you need paper to make copies of important documents, you need
floppy disks to copy the information on your hard disk. You can probably buy
the floppy disks at the same place you bought your computer.
Floppy disks come in a variety of sizes and capacities. The ones you need for
backing up your hard disk are called high-density 3.5-inch disks. You can
recognize the disks by the way they look:
Even though these disks have a hard plastic casing, they are called “floppy
disks” because the disk inside the casing is floppy.
Depending on exactly what was installed on your computer at the factory, the
information on your hard disk will fill more than 20 high-density disks. Disks
usually come in boxes of 10, so you should have three boxes of disks before
starting to follow the backup instructions in this chapter.
If you don’t have enough disks, you can skip this section for the moment. But
the sooner you make the backup copy, the better. Buy the disks as soon as
possible, then return to this section and follow the instructions.
For more information on using floppy disks, see “Using Disks” in the
Macintosh Reference book.
High-density disks
have two holes...
...and they have
this symbol.
7 Setting Up Your PowerBook