Commodore VIC-20 User Manual page 280

266
The VIC 20 User Guide
I. Turn off all drives except the one you are changing.
2. Open a command file, such as
OPEN
l~le,l~
3. Enter the following command sequence. Note: Don't worry if you
don't understand this sequence; this kind of instruction is covered in
more detail in the section on advanced disk commands.
PRINTll~,IM-W"CHR.(119)CHR.(0)CHR'(2)CHR'(9+32)CHR'(9+64)
This instruction will change the disk to device number 9. To
change the disk drive to another device number, add that number,
instead of 9, to 32 and 64 at the end of the command.
4. Turn on the next drive and repeat the command sequence above,
using a different device number for each drive added.
Note: Do not turn off any drive that has been changed. This will erase
the new device number.
Disk Data Flies
Just as there is a difference in the way that data files and program files
are handled by the Datassette, there is a difference in the way that data files
and program files are handled by the disk drive.
There are three different kinds of information that can be stored on the
disk drive. The first, program files, has already been covered. The second
type is sequential data files, and the third, random access files.
SEQUENTIAL FillS
Like sequential data files on the Datassette, sequential data files on the
1540 Disk Drive must be opened before they can be accessed. To open a
sequential data file to the disk, use the following format:
OPEN lin, dn, sa, "drn:file name,SEQ,W"
where:
Ifn
is the logical file number
dn
is the device number for the disk drive