Mit6e Ch02 by Firli

8/6/2019 Mit6e Ch02 by Firli

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Copyright 2009 Pearson Education, Inc. Publishing as Prentice Hall 1

Managing Information Technology

6th Edition

CHAPTER 2

COMPUTER HARDWARE


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Building Blocks of InformationTechnology

Hardware Software Network Data


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EVOLUTION OF COMPUTER SYSTEMS


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First Generation of Computers

Vacuum Tubes

Magnetic Drum Memories

First Generation

(1946-1959)


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Second Generation of Computers

Transistors

Magnetic Core Memories

First Generation

(1946-1959)

Second Generation

(1959-1964)


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Third Generation of Computers

Integrated Circuits

Semiconductor Memories

Operating System

First Generation

(1946-1959)

Second Generation

(1959-1964)

Third Generation

(1964-late 1970s)


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Fourth Generation of Computers

Large-Scale Integration (LSI) and Very-Large-Scale

Integration (VLSI) Circuits

Communication Between Computers

Multiple Processors in a Single Machine

First Generation

(1946-1959)

Second Generation

(1959-1964)

Third Generation

(1964-late 1970s)

Fourth Generation

(1980s-present)


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Minicomputers

Same Technologies as Third and Fourth

Generations

Smaller Machine Size

Smaller Business and Scientific Applications

First Generation

(1946-1959)

Second Generation

(1959-1964)

Third Generation

(1964-late 1970s)

Fourth Generation

(1980s-present)

Minicomputers

(1970s-present)


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Microcomputers

Microprocessors

Single-User Systems

First Generation

(1946-1959)

Second Generation

(1959-1964)

Third Generation

(1964-late 1970s)

Fourth Generation

(1980s-present)

Minicomputers

(1970s-present)

Microcomputers

(late 1970s-present)


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BASIC COMPONENTS OF

COMPUTER SYSTEMS


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

All computers made upof the same set of six

building blocks: input,output, memory,arithmetic/logic unit,control unit, and files

Control unit andarithmetic/logical unittogether known as thecentral processing unit(CPU)


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Device(s) needed to

enter data into the

computer for it to use

in its computations

Input


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Terminal

Simpler than a PC

Designed strictly for input and output

Has keyboard and screen

Does not have a processor

Connected to computer with telecommunicationline

Allows user to key data directly into computer

Input


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Common input methods

Keyboard: input entered by user through keystrokes

Disk drive: data on disk read into memory

Magnetic ink character recognition (MICR): used to

process bank checks

Bar code labeling: scans bar codes on packages orproducts, and reads into computer

Input


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Common input methods (contd)

Optical character recognition (OCR): directly scans

typed, printed, or handwritten material

Imaging: inputs digital form of documents and

photos

Input


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Device(s) needed to

produce results in a

usable format

Output


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Common output methods

Video display unit: displays output on a screen

Disk drive: output written to disk for retrieval later

Printer: output to paper using various types of

printers

Output


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Common output methods

Computer output microfilm (COM): microfilm

generated for archive copies in small space

Voice response units: computer recognizes input,

generates verbal response messages

Output


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Referred to as main

memory or primary

memory

All data flows to and

from memory

Memory


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Divided into cells

Each has a unique address

Can only store limited amount of data

Byte: stores one character of data

Word: stores two or more characters of data

Memory


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BASIC COMPONENTS OF

COMPUTER SYSTEMSMemory


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Each memory cell is a set of circuits

Each circuit is on or off (represented by 1 or 0)

Each circuit corresponds to a bit (binary digit) Most computers 8 bits (circuits) represents a

character (byte)

2 common bit coding schemes used today: ASCII

EBCDIC

Memory


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BASIC COMPONENTS OF

COMPUTER SYSTEMSMemory

.

.

.


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Carries out:

Mathematical

operations (addition,subtraction,multiplication,division)

Logical operations(numbercomparisons)

Arithmetic/logic unit


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Consists of VLSI circuits on a silicon chip

Can perform up to billions of operations per

second

Numbers are taken from memory as input and

results are stored in memory as output

Arithmetic/logic unit


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

File devices used to

store vast quantities

of data

Computer files


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Main memory is limited, volatile, andexpensive

File devices, or secondary memory, are usedto store additional data that is nonvolatile

Main disadvantage is the relatively slow speed

File storage devices: Magnetic tape drives, disk drives, floppy drives

Optical CD or DVD drives

Computer files


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Sequential Access Files

Records are stored in sequence according to files

control key

Usually stored on magnetic tape

Direct Access Files

Records can be accessed immediately, withoutregard to physical location

Stored on Direct Access Storage Devices (DASD)

Computer files


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Types of DASDs:

Fixed (hard) drives

Optical disk storage

CD-ROM

CD-R

CD-RW

DVD-ROM

DVD-R

DVD-RW

Computer files


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Types of DASDs:

Removable drives

Floppy drives

Zip drives

Keychain drives

Computer files


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Controls the other

five components of

the computer system

Control unit


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BASIC COMPONENTS OF

COMPUTER SYSTEMS

Used to take advantage of speed and capacity

of other components

List of operations, called a program, tells the

control unit what to do

These operations are read from memory,

interpreted, and carried out one at a time(stored-program concept)

Control unit


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STORED-PROGRAM CONCEPT

Program

A list of what is to be done for an application

Each step or operation is called an instruction

Machine language

Form of a program that can be understood by a

specific computer model

Consists of operation code and addresses


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Measure of computer power

Millions of instructions per second (MIPS)

Millions of floating point operations per second

(MFLOPS)

Benchmarking involves running a set of real jobs

on various machines to compare speed


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Benchmarking


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EXTENSIONS TO THE BASIC MODEL

High-speed, high-cost storage

Used as intermediary between control unit and

main memory

Compensates for speed mismatches built into the

computer system

Cache memory


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Locality of reference

If a piece of data is used, there is a high probability

that a nearby piece of data will be used shortlythereafter

Data reuse

Data is retained in cache until it has not been recently

referenced

Cache memory


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Systems that contain more than one processor

Dual-processor vs. dual-core

Dual-processor systems contain two physically

separate processors in the same box

Dual-core systems contain two complete

processors manufactured as part of a single chip

Multiprocessor systems


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Symmetric multiprocessor (SMP)

All processors are identical and work independently of

each other

Parallel processor (PP)

Multiple processors work on separate pieces of the

same program

Massively parallel processor (MPP)

Machines with a large number of parallel processors

Multiprocessor systems


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TYPES OF COMPUTER SYSTEMS

Also called personal computers or PCs

Can generally be carried or moved by one person

and only have one keyboard and display unit

Examples:

Desktop PC

Laptop or notebook

Handheld or palmtop

Tablet PC

Microcomputers


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Microcomputers


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Two major types of microcomputers IBM-compatible PCs

Apple microcomputers

Have been put to a myriad of uses Record-keeping

Word processing

Games

Presentations

Programming

Microcomputers


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Broadest category of computer systems

Workstations

More powerful microcomputers Success due to development of the reduced

instruction set computing (RISC) chip

Minicomputers Similar to mainframe systems, but less powerful and

less expensive Used for departmental computers, office automation,

and servers

Midrange systems


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Subcategories Low-end midrange systems

Essentially high-powered PCs Typically built on Intel Pentium, Celeron, or Xeon processors

or AMD Opteron processors

Often run Windows Server

High-end midrange systems

Powered by RISC processors or top-of-the-line Intel or AMDprocessors

Usually run Linux or some variation of UNIX

Midrange systems


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The heart of the computer systems for mostmajor corporations and government agencies

Major strength is versatility in applications Online and batch processing

Standard business applications

Engineering and scientific applications

Network control

Systems development

Web serving

Mainframe computers


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Mainframe computers


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Serve as number-crunchers

Handle problems generated by research scientists

High-end supercomputers located in governmentresearch laboratories and major universities

Fastest supercomputer (IBM Blue Gene/L)

incorporates 65,536 processors and can achieve

performance of 280.6 teraflops

Supercomputers


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All rights reserved. No part of this publication may be reproduced, stored in a

retrieval system, or transmitted, in any form or by any means, electronic,

mechanical, photocopying, recording, or otherwise, without the prior written

permission of the publisher. Printed in the United States of America.

Copyright 2009 Pearson Education, Inc.Publishing as Prentice Hall

Mit6e Ch02 by Firli

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