Download CATEGORIES_OF_HARDWARE_1

NAME: AMURE OLUWATOBILOBA
DEPARTMENT: LAW
COURSE: INTRODUCTION TO ICT
COURSE CODE: GST 115
ASSIGNMENT
CATEGORIES OF HARDWARE
The 6 main categories of Computer hardware are Input Devices, output Devices, CPU ,
Main Memory, Telecommunications Devices, and Secondary Storage.
Input Device
An input device is any hardware device that sends data to a computer, allowing you to interact
with and control the computer. The most commonly used input devices on a computer are
the keyboard and mouse. However, there are dozens of other devices that can also be used to input
data into the computer. Below is a list of computer input devices that can be used with a computer
or a computing device.
Types of input devices

Audio conversion device

Barcode reader

Biometrics(e.g. fingerprint scanner)

Business Card Reader

Digital camera and Digital Camcorder

Electroencephalography (EEG)

Finger (with touchscreen or Windows Touch)

Gamepad, Joystick, Paddle, Steering wheel, and Microsoft Kinect

Gesture recognition

Graphics tablet

Keyboard

Light gun and light pen scanner

Magnetic ink (like the ink found on checks)

Magnetic-stripe reader

Medical imaging devices (e.g., X-Ray, CAT Scan, and Ultrasound images)

Microphone (using voice speech recognition or biometric verification)

MIDI keyboard

MICR

Mouse, touchpad, or other pointing device

Optical Mark Reader (OMR)

Paddle

Pen or Stylus

Punch card reader

Remote

Scanner

Sensors (e.g. heat and orientation sensors)

Sonar imaging devices

Touch screen

Video capture device

VR helmet and gloves

Webcam

Yoke
Output device
An output device is any peripheral that receives data from a computer, usually for display,
projection, or physical reproduction. A good example of an output device is a computer
monitor, which displays an image that is received from the computer. Monitors and printers
are two of the most common output devices used with a computer.
Below is a listing of all the different output devices used with a computer.
Types of output devices

3D Printer

Braille embosser

Braille reader

Flat panel

GPS

Headphones

Computer Output Microfilm (COM)

Monitor

Plotter

Printer(Dot matrix printer, Inkjet printer, and Laser printer)

Projector

Sound card

Speakers

Speech-generating device (SGD)

TV

Video card
CENTRAL PROCESSING UNIT (CPU)
The central processing unit (CPU) is the brain of your computer. It handles all the
instructions you give your computer, and the faster it does this, the better. The CPU is
sometimes also referred to as the central processor unit, or processor for short.It connects
other components and direct them according to the available program.All other hardware
components of computer system connect to CPU in order to carry out instructions.These
other components cannot work on their own withour CPU.
A typical CPU has a number of components. The first is the arithmetic logic unit (ALU), which
performs simple arithmetic and logical operations. Second is the control unit (CU), which
manages the various components of the computer. It reads and interprets instructions from
memory and transforms them into a series of signals to activate other parts of thecomputer.
The control unit calls upon the arithmetic logic unit to perform the necessary calculations.
Third is the cache, which serves as high-speed memory where instructions can be copied to
and retrieved. Early CPUs consisted of many separate components, but since the 1970s, they
have been constructed as a single integrated unit called a microprocessor. As such, a CPU is
a specific type of microprocessor. The individual components of a CPU have become so
integrated that you can't even recognize them from the outside. This CPU is about two
inches by two inches in size. CPUs are located on the motherboard. Motherboards have a
socket for this, which is specific for a certain type of processor. A CPU gets very hot and
therefore needs its own cooling system in the form of a heat sink and/or fan. The ALU is
where the calculations occur, but how do these calculations actually get carried out? To a
computer, the world consists of zeros and ones. Inside a processor, we can store zeros and
ones using transistors. These are microscopic switches that control the flow of electricity
depending on whether the switch is on or off. So the transistor contains binary information:
a one if a current passes through and a zero if a current does not pass through.
Transistors are located on a very thin slice of silicon. A single silicon chip can contain
thousands of transistors. A single CPU contains a large number of chips. Combined, these
only cover about a square inch or so. In a modern CPU, however, that square inch can hold
several hundred million transistors - the very latest high-end CPUs have over one billion!
Calculations are performed by signals turning on or off different combinations of transistors.
And more transistors means more calculations.
MAIN MEMORY
A component of the computer, which is used to store data and instructions, is
called memory. The personal computer contains a main memory. A program is first loaded in
the computer memory before it is executed. The instructions of the loaded program are
executed one by one by the CPU. The data and results of calculations are also stored in the
main memory. The main memory is also known as working area of the computer. A
computer cannot work without having main memory.
A computer system consists of three types of memories.
i) Random Access Memory (RAM)
ii)Read Only Memory( ROM)
iii)Complementary Metal Oxide Semi-Conductor Memory(CMOS)
RAM
RAM (pronounced ramm) is an acronym for random access memory, a type of computer
memory that can be accessed randomly; that is, any byte of memory can be accessed
without touching the preceding bytes. RAM is the most common type of memory found
in computers and other devices, such as printers.
Main Types of RAM
There are two main types of RAM:

DRAM (Dynamic Random Access Memory)

SRAM (Static Random Access Memory).
The two types of RAM differ in the technology they use to hold data, with DRAM being the
more common type. In terms of speed, SRAM is faster. DRAM needs to be refreshed
thousands of times per second while SRAM does not need to be refreshed, which is what
makes it faster than DRAM.
ROM
Read-only memory (ROM) is a class of storage medium used in computers and other
electronic devices. Data stored in ROM can only be modified slowly, with difficulty, or not at
all, so it is mainly used to distribute firmware (software that is very closely tied to
specific hardware and unlikely to need frequent updates).
CMOS
Short for complementary metal oxide semiconductor. Pronounced see-moss, CMOS is a
widely used type of semiconductor. CMOS semiconductors use both NMOS (negative
polarity) and PMOS (positive polarity) circuits. Since only one of the circuit types is on at any
given time, CMOS chips require less power than chips using just one type of transistor. This
makes them particularly attractive for use in battery-powered devices, such
as portable computers. Personal computers also contain a small amount of battery-powered
CMOS memory to hold the date, time, and system setup parameters.
TELECOMMUNICATION DEVICES
Telecommunications refers to the exchange of information by electronic and electrical
means over a significant distance. A complete telecommunication arrangement is made up
of two or more stations equipped with transmitter and receiver devices. A single coarrangement of transmitters and receivers, called a transceiver, may also be used in many
telecommunication stations.
Telecommunications devices include telephones, telegraph, radio, microwave
communication arrangements, fiber optics, satellites and the Internet.
Telecommunications is also known as telecom. Telecommunications is a universal term that
is used for a vast range of information-transmitting technologies such as mobile phones,
land lines, VoIP and broadcast networks.
In telecommunications, data is transmitted in the form of electrical signals known as carrier
waves, which are modulated into analog or digital signals for transmitting information.
Analog modulation such as that used in radio broadcasting is an amplitude modulation.
Digital modulation is just an updated form of this.
Telecommunications and broadcasting are administered worldwide by an agency of the
United Nations called the International Telecommunication Union (ITU). Most countries
have their own agencies for enforcing telecommunications regulations.
SECONDARY STORAGE
Alternatively referred to as external memory,secondary memory, and auxiliary
storage, a secondary storage device is a non-volatiledevice that holds data until it is
deleted or overwritten. Secondary storage is about two orders of magnitude cheaper
than primary storage. Consequently, hard drives (a prime example of secondary
storage) are the go-to solution for nearly all data kept on today's computers.
Modern computer systems typically have two orders of magnitude more secondary
storage than primary storage and data are kept for a longer time there.
In modern computers, hard disk drives are usually used as secondary storage. The
time taken to access a given byte of information stored on a hard disk is typically a
few thousandths of a second, or milliseconds. By contrast, the time taken to access a
given byte of information stored in random-access memory is measured in billionths
of a second, or nanoseconds. This illustrates the significant access-time difference
which distinguishes solid-state memory from rotating magnetic storage devices: hard
disks are typically about a million times slower than memory. Rotating optical
storage devices, such as CD and DVD drives, have even longer access times. With disk
drives, once the disk read/write head reaches the proper placement and the data of
interest rotates under it, subsequent data on the track are very fast to access. To
reduce the seek time and rotational latency; data are transferred to and from disks
in large contiguous blocks.
When data reside on disk, block access to hide latency offers a ray of hope in
designing efficient external memory algorithms. Sequential or block access on disks
is orders of magnitude faster than random access, and many sophisticated
paradigms have been developed to design efficient algorithms based upon
sequential and block access. Another way to reduce the I/O bottleneck is to use
multiple disks in parallel in order to increase the bandwidth between primary and
secondary memory.
Some other examples of secondary storage technologies are flash memory (e.g. USB
flash drives or keys), floppy disks, magnetic tape, paper tape, punched cards,
standaloneRAM disks, and Iomega Zip drives.
The secondary storage is often formatted according to a file system format, which
provides the abstraction necessary to organize data into files and directories,
providing also additional information (called metadata) describing the owner of a
certain file, the access time, the access permissions, and other information.
Most computer operating systems use the concept of virtual memory, allowing
utilization of more primary storage capacity than is physically available in the system.
As the primary memory fills up, the system moves the least-used chunks (pages) to
secondary storage devices (to a swap file or page file), retrieving them later when
they are needed. As more of these retrievals from slower secondary storage are
necessary, the more the overall system performance is degraded.