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MANAGING
INFORMATION
TECHNOLOGY
FIFTH EDITION
CHAPTER 2
COMPUTER SYSTEMS
E. Wainright Martin Carol V. Brown Daniel W. DeHayes
Jeffrey A. Hoffer William C. Perkins
EVOLUTION OF COMPUTER
SYSTEMS
First Generation of Computers
1. Vacuum tubes
1946-1959
© 2005 Pearson Prentice-Hall
Chapter 2 - 2
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EVOLUTION OF COMPUTER
SYSTEMS
Second Generation of Computers
1. Vacuum tubes
2. Transistors
1946-1959
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Chapter 2 - 3
1957-1963
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EVOLUTION OF COMPUTER
SYSTEMS
Third Generation of Computers
1. Vacuum tubes
2. Transistors
3. Integrated circuits
1946-1959
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1957-1963
1964-1979
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EVOLUTION OF COMPUTER
SYSTEMS
Fourth Generation of Computers
1.
2.
3.
4.
Vacuum tubes
Transistors
Integrated circuits
VLSI (very-large-scale integrated) circuits
1946-1959
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Chapter 2 - 5
1957-1963
1964-1979
1980 - present
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EVOLUTION OF COMPUTER
SYSTEMS
The Development of Minicomputers
Data General
DEC
Hewlett-Packard
IBM
1946-1959
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Chapter 2 - 6
1957-1963
1964-1979
1980 - present
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EVOLUTION OF COMPUTER
SYSTEMS
The Development of Microcomputers
Apple
IBM PC
1981
1946-1959
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1957-1963
1964-1979
1980 - present
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
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Chapter 2 - 8
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Chapter 2 - 9
Table 2.1 Evolution of Intel Microprocessor
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Underlying Structure
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Chapter 2 - 10
Figure 2.4 Logical Structure of Digital Computers
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Input/Output
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Input/Output
Terminal
Simpler
than a PC
Designed strictly for input and output
Has keyboard and screen
Does not have a processor
Connected to computer with
telecommunication line
Allows user to key data directly into computer
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Input/Output
Terminal
Special
types:
Point-of-sale (retail)
ATMs (banking)
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Input/Output
Common input methods:
Magnetic ink character recognition (MICR) –
used to process bank checks
Optical character recognition (OCR) – directly
scans typed, printed, or handwritten material
Imaging – inputs digital form of documents and
photos
Bar code labeling – scans bar codes on
packages or products, and reads into computer
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Input/Output
Common output methods:
– output to paper using various types of
printers
Computer output microfilm (COM) – microfilm
generated for archive copies in small space
Voice response units – computer recognizes
input, generates verbal response messages
Print
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Input/Output
Multimedia –
relatively new term for computer input and output
in the form of text, graphics, sound, still images,
animations, and/or video
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Memory
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Memory
Memory
All
data flows to and from memory
Divided into cells:
Each has a unique address
Memory cell types:
Byte – stores one character of data
Word – stores two or more characters of data
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Bits and Coding Schemes
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
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Bits and Coding Schemes
.
.
.
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.
.
.
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.
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Figure 2.4 Computer Coding Schemes
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Arithmetic/Logical Unit
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Arithmetic/Logical Unit
Consists of VLSI circuits
on a silicon chip
Carries out:
– add, subtract,
multiply, divide …
logical operations –
comparing two numbers
arithmetic
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Files
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Files
When power is off, everything stored in
memory is lost
Computer files are used to store data long
term
File storage devices:
Magnetic
tape drives, disk drives, floppy
drives
Optical CD or DVD drives
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Files
Sequential access files
Usually
stored on magnetic tape drives
Direct access files
Stored
on Direct Access Storage Devices
(DASD) - magnetic disk drives
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Files
Types of DASD
Fixed
© 2005 Pearson Prentice-Hall
(hard) drives
Chapter 2 - 26
Figure 2.7 Diagram of a Magnetic Disk Drive
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Files
Types of DASD
Removable:
Floppy drives
Zip drives
Newest: portable
DASD for PCs –
keychain drive
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Figure 2.8 Iomega’s Mini USB Keychain Drive
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Computer Files
Newer type of DASD
Optical
Disk Storage
CD-ROM
CD-R
CD-RW
700 megabytes
read-only
recordable
rewritable
DVD-ROM
DVD-R
DVD-RW
4.7 gigabytes
read-only
recordable
rewritable
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Control Unit
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BASIC COMPONENTS
OF COMPUTER SYSTEMS
Control Unit
Controls computer to take advantage of
speed and capacity of other components
Directed by list of operations (program)
that tells control unit what to do
Uses the stored-program concept
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THE STORED-PROGRAM CONCEPT
Program – list of what computer needs to
do for an application
Instruction – each individual step or
operation in a program
Control unit – carries out one step or
instruction at a time at electronic speed
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THE STORED-PROGRAM CONCEPT
Note: One of the primary measures of
power of computers is the number of
instructions it can execute in a given
period
MIPS – millions of instructions per second
executed by the control unit
MFLOPS – millions of floating point operations per
second
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THE STORED-PROGRAM CONCEPT
Top Seven Desktop PCs – Power System
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Table 2.2
Benchmarking
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EXTENSIONS TO THE BASIC MODEL
Communications within
the Computer System
Terminals
Magnetic
Tape Units
Magnetic
Disk Units
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Figure 2.9
Data Channels and Controllers
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Data Channel
A specialized I/O Processor that takes
over function of device communication
from the CPU
Its role is to corrects for speed mismatch
between slow peripheral devices and very
fast CPU
It includes buffer storage
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Controllers
A highly specialized microprocessor that
manages the operation of the attached
devices to free up the CPU and the data
channel from these tasks.
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EXTENSIONS TO THE BASIC
MODEL
Cache Memory
High-speed storage to
temporarily hold data from
main memory waiting to be
processed
Entire blocks of data
moved at one time into
cache
Enables CPU to execute
much faster
Also incorporated into
DASD controllers
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Figure 2.10
Cache Memory
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EXTENSIONS TO THE BASIC
MODEL
Multiple Processor Configurations
Multiprocessor
Symmetric multiprocessor (SMP)
Vector facility
Parallel processor (PP)
Massively parallel processor (MPP)
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TYPES OF COMPUTER SYSTEMS
Microcomputers
Cost in $
MFLOPS
200-3,000
20-400
Major Vendors
Primary Uses
IBM, Dell,
Personal computing
Hewlett-Packard, Client in client/server
Gateway, Fujitsu, applications
Toshiba
Web client
Small business
processing
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TYPES OF COMPUTER SYSTEMS
Workstation/Midrange Systems
Cost in $
MFLOPS
Major Vendors
3,000-1,000,000 40-4,000 IBM, Dell,
Hewlett-Packard,
Gateway, NEC,
NCR, Fujitsu,
Toshiba, Sun
Microsystems
Primary Uses
Departmental
computing
Specific applications
(office automation,
CAD, other graphics)
Midsized business
general processing
Server in client/server
applications
Web server, file
server, LAN server
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TYPES OF COMPUTER SYSTEMS
Mainframe Computers
Cost in $
MFLOPS
1,000,000 20,000,000
200 8,000
Major Vendors
IBM, Fujitsu,
Groupe Bull,
Unisys
Primary Uses
Large business
general processing
Server in client/server
applications
Large Web server
Widest range of
applications
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TYPES OF COMPUTER SYSTEMS
Supercomputers
MFLOPS
Cost in $
1,000,000 100,000,000
© 2005 Pearson Prentice-Hall
Major Vendors
4,000 IBM, Hewlett100,000,000 Packard, Dell,
Hitachi, Cray,
NEC
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Primary Uses
Numerically intensive
scientific calculations
Very large Web
server
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