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CHAPTER
3
HARDWARE
CHAPTER OUTLINE
1.1 Introduction
1.2 Strategic Hardware Issues
1.3 Computer Hierarchy
1.4 Input and Output Technologies
1.5 The Central Processing Unit
LEARNING OBJECTIVES
1. Identify the major hardware components of a
computer system.
2. Discuss the strategic issues that link hardware design
to business strategy.
3. Describe the hierarchy of computers according to
power and their respective roles.
4. Differentiate the various types of input and output
technologies and their uses.
LEARNING OBJECTIVES
5. Describe the design and functioning of the central
processing unit.
6. Discuss the relationships between microprocessor
component designs and performance.
7. Describe the main types of primary and secondary
storage.
8. Distinguish between primary and secondary storage
along the dimensions of speed, cost, and capacity.
1.1 Introduction to Hardware
Hardware
Hardware refers to the physical equipment used
for the input, processing, output, and storage
activities of a computer system.
Hardware consists of:
Central Processing
Unit (CPU)
Manipulates the data and controls the tasks
performed by the other components.
Primary Storage
Internal to the CPU; temporarily stores data
and program instructions during processing.
Secondary Storage
External to the CPU; stores data and programs
for future use
Input Technologies
Accept data and instructions and convert them
to a form that the computer can understand.
Output Technologies
Present data and information in a form people
can understand.
Communication
Technologies
Provide for the flow of data from external
computer networks (e.g. the Internet and
intranets) to the CPU, and from the CPU to
computer networks.
1.2 Strategic Hardware Issues
• The key issues with hardware are WHAT in enables and how
to keep up with rapid price/ performance increases.
• In many industries, exploiting computer hardware is essential
to achieving competitive advantage.
• Successful hardware exploitation come from thoughtful
consideration of the following questions:-
HOW will the
organization keep
up with the rapid
and performance
advancements in
hardware
EG: How often
should the
organization
upgrade its
computers and
storage system?
HOW
should the
organization
determine the need
for new hardware
infrastructures, such
as server farms,
virtualization, grid
computing, and
utility computing?
Portable computers
and advanced
communications
technologies enable
employees to work
from home or
almost any other
location.
1.3 Computer Hierarchy
• Supercomputers
• Mainframe Computers
• Midrange Computers
• Microcomputers
Supercomputers
• The faster computers available at any given time.
• Supercomputers are costly as well as fast, large organizations
generally use them to execute computationally demanding tasks
involving large data set.
• Typically run military and scientific applications.
• Although these machines cots millions of dollars, they are also being
used for commercial applications where huge amounts of data must be
analyzed.
• EG:- Large banks employ supercomputers to calculate the risks and
returns of various investment strategies, and healthcare
organizations use them to analyze giant database of patient data
to determine optimal treatments for various diseases.
Mainframe Computer
• Mainframes remain popular in large enterprise for
extensive computing applications that are accessed by
thousands of users simultaneously.
•
EG:- Mainframes applications are airline reservation
•
Today’s mainframes perform at teraflop speed
(trillions of floating point operations per second)
and can handle millions of transaction per day.
systems, corporate payroll program, website
transaction processing system ( Amazon and
eBay)’
Midrange Computers
• Larges midrange computers call minicomputers, are
relatively small, inexpensive, and compact computers that
perform the same functions as mainframes computer.
•
The lines between minicomputers and mainframes have
blurred in both price and performance.
•
Minicomputers are a type of server that is computer that
supports computer networks and enables users to share files,
software, peripheral devices, and other resources.
MICROCOMPUTERS
•
Also called micros, personal computers, or PCs are the
smallest and least expensive category of general-purpose
computer.
Desktop PCs
* The Desktop Personal Computer is the familiar
microcomputer system that has been a standard tool for
business at the home. microcomputer
Laptop and Notebook Computers
* A small, light weight microcomputers that fit easily into a
briefcase.
* Designed to be as convenient and easy to transport as
possible.
* Provide users with access to processing power and data
outside an office environment.
* They cost more than desktop for similar functionality.
Netbooks
* Is a very small, lightweight, portable computer that is
energy efficient and relatively inexpensive.
* Netbooks generally optimized for Internet based services
such as web browsing and e-mailing.
Tablet Computers
* Is a complete computer contained entirely in a flat touch
screen that users operate via a stylus, a digital pen, or
their finger tip instead of a keyboard and mouse.
* EG:- Apple iPad, HP Slate, the Toshiba Thrive and the
Motorola Xoom
1.4 Input and Output Technologies
• 2 main types of input devices are HUMAN DATA ENTRY DEVICE and
SOURCE DATA AUTOMATION DEVICE
HUMAN DATA ENTRY
DEVICE
•implies, require a certain
amount of human effort
to input data.
•EG keyboard, mouse,
pointing stick, trackball,
joystick, touch screen,
stylus and voice
recognition.
SOURCE DATA
AUTOMATION DEVICE
•With minimal human
intervention.
•Speed up data
collection, reduce errors,
and gather data at the
source of a transaction
or other event.
•EG Barcode Readers,
ATMs and radio
frequency identification
Various Human Input Devices
•Trackball
•Pointing Stick
•Digital Pen
•Web Camera
•Wii
© MONKEY BUSINESS-LBR/Age Fotostock America, Inc.
•Bluetooth Laser
•Virtual Keyboard
•The Maltron Keyboard
Source: WENN Photos/NewsCom
We’ve Come a Long Way
A very early (if not the first) mouse demonstration
in 1968.
See the video of Oblong’s product, called G-Speak
The First Mouse
A very early (if not the first) mouse demonstration
in 1968.
Output Technologies
Output generated by a computer can be transmitted to
the user over several output devices and media, which
include:
Monitors
Printers
Plotters
Voice
Electronic Book Readers
Amazon’s Kindle 3
Sony Reader
Asus ebook
Reader
Barnes and
Noble Nook
© Andriy Kravchenko/Age Fotostock America, Inc.
Multimedia Technology
Multimedia technology
• is the computer-based integration of text, sound, still images,
animation, and digitized motion video.
Merges capabilities of computers with televisions, VCRs, CD
players, DVD players, video and audio recording equipment,
music and gaming technologies.
1.5 The Central Processing Unit
Central processing unit (CPU)
* Performs the actual computation or "number crunching”
inside any computer.
Microprocessor
* Made up of millions of microscopic transistors embedded in
a circuit on a silicon chip.
Control unit
sequentially accesses
program instructions,
decodes them and
controls the flow of data
to and from
the ALU, the registers, the
caches, primary storage,
secondary storage and
various output devices.
Arithmetic-logic
unit (ALU) performs
the mathematic
calculations and makes
logical comparisons
Registers are high-
speed storage areas that
store very small amounts
of data and instructions
for short periods of time
.
Central Processing Unit (CPU)
How the CPU Works
•The inputs consist of data and brief instructions about what to do with the data
These instructions come from software in other parts of the computer.
Data might be entered by the user through the keyboard,
for example, or read from a data file in another part of the computer.
The inputs are stored in registers until they are sent to the next step in the
processing.
•Data and instructions travel in the chip via electrical pathways called buses.
The size of the bus analogous to the width of a highway determines how much
information can flow at any time.
•The control unit directs the flow of data and instructions within the chip.
•The arithmetic-logic unit (ALU) receives the data and instructions from the
registers and makes the desired computation. These data and instructions have
been translated into binary form, that is, only 0s and 1s. The CPU can process
only binary data.
•The data in their original form and the instructions are sent to storage registers
and then are
• sent back to a storage place outside the chip, such as the computer’s
hard drive .
•Meanwhile, the transformed data go to another register and then on
to other parts of the computer (to the monitor for display or to storage, for example)
Advances in Microprocessor Design
Moore’s Law: microprocessor complexity would
double every two years.
The Evolution of Chips
For a look at the evolution of chips from the
Intel 4004 to multicore chips, click here.
Computer Memory
2 basic categories of computer memory:
Primary Storage
* Stores small amounts of data and information that will be
immediately used by the CPU.
Secondary Storage
* stores much larger amounts of data and information (an
entire software program, for example) for extended
periods of time.
Memory Capacity:
Bit: Short for binary digit (0s
and 1s), the only data that a CPU
can process.
Byte: An 8-bit string of
data, needed to represent
any one alphanumeric
character or simple
mathematical operation.
Hierarchy of Memory Capacity
Kilobyte(KB)
approximately one thousand bytes
Megabyte(MB)
approximately one million bytes (1,048,576 bytes,
or 1,024 x 1,024).
Gigabyte(GB)
actually 1,073,741,824 bytes (1,024 x 1,024 x 1,024
bytes).
Terabyte
One trillion bytes.
Petabyte
One thousand terabytes.
Exabyte
One thousand petabytes.
Zettabyte
One thousand exabytes.
Main Types of Primary Storage
Registers:
registers are part of the CPU with the least
capacity, storing extremely limited
amounts of instructions and data only
immediately before and after processing
Random access
memory (RAM):
The part of primary storage that holds a
software program and small amounts of
data when they are brought from secondary
storage.
Cache memory:
A type of primary storage where the
computer can temporarily store blocks of
data used more often.
Read-only memory
(ROM):
Type of primary storage where certain critical
instructions are safeguarded, the storage is
nonvolatile and retains the instructions when
the power to the computer is turned off.
Primary Storage
RAM
MRAM
Register
Cache
© Aleksandr Potapov/Age Fotostock America, Inc.
* Register – They have the least capacity, storing extremely limited
amounts of instruction and data only immediately before and after
processing
* Cache Memory – is a type of high- speed memory that a processor can
access more rapidly the main memory (RAM).
-Enables the computer to temporarily store frequently used block used
infrequently remain secondary storage.
-- Cache is faster than RAM
*Random Access Memory (RAM) – Is the part of primary storage that
holds a software program and small amount of data for processing.
- When a software program (such as Microsoft Word) is started, the
entire program is transferred from secondary storage into RAM.
-RAM stores more information and is located farther away from the
CPU.
- RAM is temporary and Volatile Memory = Loses its content when
power is turned off
•Read- Only Memory(ROM) – is the place
- Nonvolatile Memory = Does not lose contents when power is
removed (ROM, FLASH MEMORY)
-Read Only designation means that instruction in ROM can only be
read, not changed.
- EXAMPLE: ROM is the initial instructions needed to start or “boot”
the computer.
Internal workings of personal
computer
Hard
disk
drive
Floppy
disk
drive
CPU board
with fan
RAM
Primary versus Secondary Memory
Secondary Storage
•It is nonvolatile.
•It takes much more time to retrieve data because of the
electromechanical nature.
•It is cheaper than primary storage.
•It can take place on a variety of media
Memory capacity that can store very large amounts of data
for extended periods of time.
Magnetic tape (sequential access)
Magnetic disks (direct access)
Optical storage devices
Flash memory devices
Magnetic tape : A secondary storage medium on a large open
reel or in a smaller cartridge or cassette.
Magnetic disks : A form of secondary storage on a
magnetized disk divided into tracks and sectors
that provide addresses for various pieces of data; also called
hard disks.
Optical Storage : Laser reads the surface of a reflective
plastic platter.
Are slower than magnetic hard drives but they are less
susceptible to damage from contamination, and less fragile.
Flash Memory : Are used with digital camera, handheld and
laptop computers, telephones, music players and video
game consoles.
Hard Drive
Hard drives: A form of secondary storage that stores data on platters
divided into concentric tracks and sectors, which can be ready by a read/
/write head that pivots across the rotating disks.
Source: BraginAlexey/Shutterstock
Optical Storage Devices
Optical storage devices
A form of secondary storage in which a laser reads the surface
of a reflective plastic platter.
Compact disk, read-only memory (CD-ROM): A form
of secondary storage that can be only read and not
written on.
Digital video disk (DVD): An optical storage device
used to store digital video or computer data.
© J R Bale, Balefire C/Age Fotostock America, Inc.
Flash Memory Devices
Flash memory : non-volitile memory that can be erased and
reprogrammed.
Flash memory devices : electronic storage devices with no
moving parts
Thumb drive