Topic 6: Storage Devices Flashcards
The three main categories of storage devices are;
built-in, external and portable
Built-in storage device means the device is
part of a computer
External storage device means the device is
not part of a computer.
An external storage device is connected to the computer using
an external port
A portable device is
an external device which is easy to carry around
There are two main types of storage device;
magnetic and optical
Magnetic storage devices use
magnetic properties of some metal oxides to store data.
Magnetic storage is used in
hard disk drives and tape drives
Optical storage devices use
lasers, which can “see” and read data on optical discs.
Optical drives have lasers that read
bumps and dips as ones and zeros which the computer can understand
Optical storage is used in
CDs and DVDs
There are two many properties to consider for a storage device and they are
capacity and speed
Capacity is
how much data a disk can hold
Speed means
how fast data can be transferred from computer to disk or vice versa
The speed of transferring data from disk to computer is called the
read speed
The speed of transferring data from computer to disk is called the
write speed
CDs and DVDs can be broken into 2 basic categories and these are;
Re-writable and Read-Only
On a re-writable disk users can
create the disk and contents can be added to.
Re-writable disks are created by
a special dye which creates the 1s and 0s
Read-Only disks can only be
made by a commercial company and the user cannot alter the contents of the disk
Solid state device are devices which
have no moving parts
Solid state storage device store data using a special type of memory called
flash memory
Some solid state devices are;
USBs, Camera flash cards, Chips in smart cards and Internal memory in MP3 players
Advantages of solid state devices are that they are more
robust than hard drives, they use less power and data is accessed quicker than hard drives.
Computer interface is the point where a computer
connects to an external device. Some send/receive data more quickly than others
Most USB devices are now
USB 2 or USB 3
USB 3 is
8 times faster than USB 2
Some drives can connect using
SATA interfaces
Most internal devices now connect using
SATA cables
