COMPUTER HARDWARELecturer: Leah Marie Udtohan NiluagNursing Informatics

Objectives

List the key hardware components of a computer and the four basic operations of the central processing unit (CPU).

Describe how power is measured for computers.

Describe common computer input, output, and storage devices.

Discuss the history of computers. Describe the three classes of computers

and key functionality of each class. Describe computer

network/communications devices and functionality.

Hardware

Defined as all of the physical components of the machine itself.Basic hardware:

Electronic circuits Microchips Processors Motherboard

Includes devices that are peripheral to the main computer box such as input and output devices.

Computer Hardware Fundamentals Motherboard - a thin, flat sheet made of a

firm, non conducting material on which the internal components-printed circuits, chips, slots and so on- of the computer are mounted.- made of dielectric or non conducting plastic material and the electric conductions are etched or soldered onto the bottom of the board.

- has holes or perforations through which components can be affixed.

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Computer Hardware Fundamentals Central Processing Unit – the “brains” of

the computer - Consists of at least one arithmetic and

logic unit and memory.* the arithmetic and logic units control mathematical functions* the control unit carries out the machine language functions called fetch, execute, decode and store

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Computer Hardware Fundamentals Memory

2 types: ROM RAM

ROM (Read Only Memory) – a form of permanent storage- generally contains the programs called firmware, used by the control unit of the CPU to oversee computer functions

*ROM storage is not erased when the computer is turned off.

Computer Hardware Fundamentals

RAM (Random Access Memory) – refers to working memory used for primary storage.- a volatile and used as temporary storage- can be accessed, used, change and written on repeatedly- contains data and instructions that are stored and processed by computer programs called applications programs- the work area available to the CPU for all processing applications- the contents are lost whenever the power of the computer is turned off.

Computer Hardware Fundamentals Input and Output

Input devices – allow the computer to receive information from the outside world.

e.g. keyboard, mouse, touch screen, light pen, voice and scanner

Touch screen – both input and output device combined.

Light pen – a device attached to the computer that has special software that allows the computer to sense when the light pen is focused on a particular part of the screen.

Computer Hardware Fundamentals

Voice system – allow the nurse to speak into a microphone to record data.• Some devices are used for security and can

detect user’s finger prints, retinal prints, voice prints or other personally unique physical characteristics that identify users who have clearance to use the system.

Output devices – allow the computer to report its results to the external world- can be in the form of text, data files, sound, graphics or signals to other devices

e.g. monitor and printer

Computer Hardware Fundamentals Storage Media

common storage devices:o Hard drive o Diskettes magnetic storage mediao CD-ROMs – form of optical storage* Optical media are read by a laser “eye”

rather than a magnet

Computer Hardware Fundamentals Hard Drive – a peripheral that has very high

speed and high density- a very fast means of storing & retrieving data as well as having a large storage capacity in comparison with the other types of storage

Diskettes – a round magnetic disk encased in a flexible or rigid case- it allows the user to transport data & programs from one computer site to another

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Computer Hardware Fundamentals CD-ROM – a rigid disk that holds a much

higher density of information than a diskette & has a much higher speed

USB disk – a small removable hard drive that is inserted into the USB port of the computer- a read-write device like floppies & small enough to transport comfortably in a pants pocket

Computer Hardware FundamentalsOther output devices Magnetic tape drives – in 1980 & early

1990s were a popular way to back up hard drive data

Zip drives – more similar to ordinary floppy disks but are of higher capacity

Computer Power

Bits & bytes refer to how the machine stores information at the lowest or closest to machine registers & memory level.

bit (binary digit) – a unit of data in the binary numbering system; on= 1; off= 0- an on/off switch

Byte – made up of 8 bits

Computer Speed

The CPU speed is measured in cycles per second which one called the clock speed of the computer.

1 million cycles per second is called 1 megahertz(MHz).

Assignment: Give a brief history of computers

Classes of Computers

Analog computer – operates on continuous physical or electrical magnitudes, measuring on going continuous analog quantities such as voltage, current, temperature & pressure.- accepts input/output signalse.g. heart monitors & fetal monitors

Classes of Computers

Digital computer – operates on discrete discontinuous numeral digits using the binary numbering- data are represented by numbers, letters & symbols rather than by waveforms

Classes of Computers

Hybrid computer – features of both the analog & the digital computer- used for specific application such as complex signal processing & other engineering oriented applicationse.g. physiologic monitors that are able to capture the heart waveform & also to measure the core body temperature at specific times i.e. ECG,EEG

Types of Computers

Each type was developed as the computer industry evolved & each was developed for a different purpose.

Supercomputers (high-end computers) – largest type of computer- computational-oriented computer specially design for specific applications requiring gigantic amounts of calculations

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Types of Computers

Mainframes – fastest, largest & most expensive type of computer used for processing, storing, & retrieving data.

Microcomputers( Personal Computer or PCs) – can serve stand-alone workstations & can be linked to a network system to increase their capabilities

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Types of Computers

Handheld computers – small, special function computere.g. PDAs – can have calendar, contacts,

note- taking, word processing, spread sheet, dictionary

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Common Hardware Peripherals

Keyboard Monitor Mouse & trackball Floppy disks &

diskettes Touchpad &

mouse button

Light pen or touch screen

OCR MICR Printers Modems

Basics of Computer Network Hardware

Network - a set of cooperative interconnected computer for the purpose of information interchange.

includes : LAN, WAN, MAN The most important components of

network hardware are the adapter or interface card, cabling & server

The most important concepts in network hardware are architecture & topology.

Network Hardware

The role of hardware in a network is to provide an interconnection between computers. It must have at least 2 pieces of hardware: NIC – Network Adapter or Network Interface

a computer circuit board or card that is installed in a computer so that it can be connected to a network.

Communication medium (cabling) the means by which actual transfer of data from one

site to another takes placechoice of communication medium is based on the

following: Distance Amount of data transfer How often the transfer is needed Availability

Telephone Line Communications

Specialized phone lines called integrated services digital network (ISDN) lines are used to carry communication across phone lines.

ISDN – set of communication standards for optical fibers that carry voice, digital & video signals across phone lines.

Cable Modem

- Uses the same type of connection that cable uses

The interesting thing is that TV uses very little of the bandwidth of a cable connection, so the same cable that brings a user cable TV can

ServersOne computer is the core or server computer that receives request from the client computer and fulfill there request.

Architecture

- Refers to overall physical structure, peripherals, interconnections within the computer & its system software especially the operating system.

- Can be divided into five fundamental components: Input/output Storage Communication Control processing

Architecture

Two types of network architecture: Broadcast – done by transmitting the same

information to all computers in the network- typically used in LANs

Point-to-point – the computer for w/c information is intended is identified first, & the communication is only to that particular computer.

- typically used in “dial-up” networking

Topology

- Defines how the network components in a LAN are interconnected within a physical area & describes their physical interconnection.

Different topology: Bus – all the node computers are directly

attached to a line. Star – centralized structure where all

computers are connected through a central computer called the server.

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Topology

Ring – all LAN computers were connected in a ring fashion with wires or cables that directly connected all the computers together.

Forms: Hub – consists of a “backbone” or main

circuit, attached to a number of outgoing lines

Arcnet – uses a “token bus” system managing line sharing among all the users on the network

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Motherboard

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CPU

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Hard drive

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Diskette

High end computer

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Mainframe

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PC

Handheld computers

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Cable ModemServer

Bus topology

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Star topology

Ring topology

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