Ans : Dual Purpose Devices :
Devices that can perform both input as well as output functions are known as dual purpose devices.
Examples Of Dual Purpose Devices :
(a) Disk Drives.
(b) CD-Writers.
Disk Drive :
Disk drive is a peripheral device that reads data from disk or writes data to the disk and store it as information like hard disk , floppy disk , flash drive etc. They are also called ‘Storage Devices’ because they store information on portable or permanent disks.
Dual Functionality :
When the disk drive is used to read some data from a disk it performs input function. When the disk drive is used to write some data to the disk and store it this is called output function.
CD - Writer:
A CD – Writer is a device which can read or write on a compact disk ( CD ). CD-RW discs may be written , erased and rewritten while CD-R discs may be written only once. CD-Writer’s performance is measured in
‘X’ units . 1’X’ = 150 kilobytes / second.
Dual Functionality :
When the CD-Writer is used to read some data from a CD it performs input function. When the CD-Writer is used to write some data to the CD and store it this is called output function.