Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Secondary Storage
▪ Used in a computer system to overcome the limitations
of primary storage
▪ Has virtually unlimited capacity because the cost per bit
of storage is very low
▪ Has an operating speed far slower than that of the
primary storage
▪ Used to store large volumes of data on a
permanent basis
▪ Also known as auxiliary memory
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 1/98
, Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Classification of Commonly Used Secondary
Storage Devices
Secondary Storage
Devices
Sequential Access Direct Access Devices
Device
Magnetic Tape
Magnetic Optical Disks Memory Storage
Disks Devices
Flash Memory
Floppy Hard CD-ROM Card
WORM CD-RW Drive
Disk Disks
(CD-R) DVD
Zip Disk Disk Pack
Winchester Disk
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 2/98
, Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Sequential-access Storage Devices
▪ Arrival at the desired storage location may be preceded
by sequencing through other locations
▪ Data can only be retrieved in the same sequence in which
it is stored
▪ Access time varies according to the storage location of
the information being accessed
▪ Suitable for sequential processing applications where
most, if not all, of the data records need to be processed
one after another
▪ Magnetic tape is a typical example of such a storage
device
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 3/98
, Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Direct-access Storage Devices
▪ Devices where any storage location may be selected
and accessed at random
▪ Permits access to individual information in a
more direct or immediate manner
▪ Approximately equal access time is required for
accessing information from any storage location
▪ Suitable for direct processing applications such as on-
line ticket booking systems, on-line banking systems
▪ Magnetic, optical, and magneto-optical disks
are typical examples of such a storage device
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 4/98
Secondary Storage
▪ Used in a computer system to overcome the limitations
of primary storage
▪ Has virtually unlimited capacity because the cost per bit
of storage is very low
▪ Has an operating speed far slower than that of the
primary storage
▪ Used to store large volumes of data on a
permanent basis
▪ Also known as auxiliary memory
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 1/98
, Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Classification of Commonly Used Secondary
Storage Devices
Secondary Storage
Devices
Sequential Access Direct Access Devices
Device
Magnetic Tape
Magnetic Optical Disks Memory Storage
Disks Devices
Flash Memory
Floppy Hard CD-ROM Card
WORM CD-RW Drive
Disk Disks
(CD-R) DVD
Zip Disk Disk Pack
Winchester Disk
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 2/98
, Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Sequential-access Storage Devices
▪ Arrival at the desired storage location may be preceded
by sequencing through other locations
▪ Data can only be retrieved in the same sequence in which
it is stored
▪ Access time varies according to the storage location of
the information being accessed
▪ Suitable for sequential processing applications where
most, if not all, of the data records need to be processed
one after another
▪ Magnetic tape is a typical example of such a storage
device
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 3/98
, Computer Fundamentals: Pradeep K. Sinha & Priti Sinha
Direct-access Storage Devices
▪ Devices where any storage location may be selected
and accessed at random
▪ Permits access to individual information in a
more direct or immediate manner
▪ Approximately equal access time is required for
accessing information from any storage location
▪ Suitable for direct processing applications such as on-
line ticket booking systems, on-line banking systems
▪ Magnetic, optical, and magneto-optical disks
are typical examples of such a storage device
Ref Page 117 Chapter 8: Secondary Storage Devices Slide 4/98
