Download Computer Hardware

COMPUTER HARDWARE
Lecturer: Leah Marie Udtohan Niluag
Nursing 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 onof 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.
view image
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
view image
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:
Hard drive
o Diskettes
magnetic storage media
o CD-ROMs – form of optical storage
* Optical media are read by a laser “eye” rather than a
magnet
o
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
view image
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 Fundamentals
Other 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 signals
e.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
applications
e.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
view image
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
view image
Types of Computers

Handheld computers – small, special function
computer
e.g. PDAs – can have calendar, contacts, note- taking,
word processing, spread sheet, dictionary
view image
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 place
choice 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
Servers
One 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.
view image
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

view image
Motherboard
back
CPU
back
Hard drive
Diskette
back
High end computer
back
Mainframe
PC
back
Handheld computers
back
Cable Modem
Server
Bus topology
Star topology
back
Ring topology
back