Commodore VIC-20 User Manual page 65

Chapter 2: Operating the VIC 20
51
will always initialize itself automatically when you change diskettes.
If
you
have two diskettes that have the same ID number, you should manually
initialize the disk drive by using the following command:
OPEN
l~e
.. le .. "le"
Remember, you need to initialize only when you change diskettes, and
then only if the ID and name of the current diskette are the same as that of
the new diskette.
Note that once a program has been loaded into memory, whether from
tape, from diskette, or by hand, the computer will treat it in the same manner
so the procedures for running, listing, and making changes to the program
remain the same.
FormaHing a Diskette
Before you can record any data on a new diskette, you must first
prepare it using a process called formatting. The computer stores and
retrieves data from the diskette by accessing special locations, called sectors,
on the diskette. These locations are laid out on the diskette before any data
can be stored on it. Each sector is a small part of the tracks on the diskette.
Tracks are similar to the grooves in a phonograph record, but are arranged
in concentric circles rather than as a spiral. Figure 2-1 shows what the tracks
on a diskette might look like if you could see them. Each track is divided into
smaller pieces, called sectors, each of which may contain up to 256 bytes of
data. When you buy a new diskette, it is not divided into these sectors and
will not accept anything you try to record on it. Diskettes are not formatted
when you buy them because each disk drive manufacturer uses a slightly
different format on its diskettes. The VIC diskette must be formatted on a
VIC disk drive.
Here are two methods of formatting a diskette.
Method 1:
OPEN 1,8,15
PRINT#l,"Ndrive no.:disk name,ID no."
Example: