Transcript Welcome to CMPE003 Personal Computers

Welcome to CMPE003
Personal Computers:
Hardware and
Software
Dr. Chane Fullmer
Fall 2002
UC Santa Cruz
Class Information

Midterm #3
– Tuesday, December 3
– 4:00PM to 7:00PM
• (Or until we’re done..should take about 1 hour)
No Chapter 17 on Midterm #3
 No class meeting Wednesday, 11/27
 Last section is Tuesday, 11/26

November 25, 2002
2
Final Project

Due by December 3rd, at beginning of final
period
– May be turned in earlier 

Power Point Presentation
– Min 4 pages – Max 6
– 30% of grade based on your creativity
• Go crazy here…
– Pts for video (of self ), music, animations, sounds
– Pts for PPT tricks, styles, animations, buttons, etc..
– If you add animation or other special effects, include a
floppy/CD with your printout
– Emailed assignments will be rejected 
November 25, 2002
3
Midterm #3
Review
November 25, 2002
4
Security and Privacy:
Computers and the Internet
Chapter 11
Computer Crime
Stealing and using or selling of data:
Company data
Personal information in company files
November 25, 2002
6
Data, not equipment (cont)
Ways to secure data

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Locked servers
Removable hard drives that are locked away when not in
use
Hard disk drives requiring special tools for detachment
Physical cages around computers that prohibit access
Passwording files
November 25, 2002
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White-hat hackers


Professional Hackers..
Computer professionals hired to illicitly gain entry
into a system
– Reveal weak points
– Protect the points
– May not alert its own employees of the testing



Tiger teams
Intrusion tester
White hat hackers
November 25, 2002
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Computer Crimes

Bomb
– Program to trigger damage
– Scheduled to run at a later date
– May be found in software for general public, especially
shareware

Data diddling
– Changing data before or as it enters the system

Denial of service attack (DOS)
– Hackers bombard a site with more request for service than it
can possible handle
– Prevents legitimate users from accessing the site
– Appearance of requests coming from many different sites
simultaneously
November 25, 2002
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Computer Crimes

Salami technique
– Embezzlement
– A “little slice” from every transaction can add up 

Scavenging
– Search garbage and recycling bins for personal information

Trapdoor
– Illicit program left within a completed legitimate program
– Permits unauthorized and unknown entry to the program

Trojan horse
– Illegal instructions placed inside a legitimate program
– Program does something useful and destructive at the same time
November 25, 2002
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Computer Crimes

Discovery
– Difficult
– Accidental
– 85% of computer crimes are never reported

Prosecution
– Legal representatives lack technical knowledge
to understand the crime
November 25, 2002
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Security
System of safeguards designed to protect a
computer system and data from deliberate or
accidental damage




Natural disasters
Fire
Accidents
Vandalism
November 25, 2002


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Theft
Theft or destruction of
data
Industrial espionage
Hackers
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Security
Identification and Access


Provide access to authorized individuals only
Uses one of more of the following systems
– What you have
• Key, badge, token, etc..
– What you know
• Password, PIN number
– What you do
• Signature
– What you are
• Biometrics – fingerprint, retinal scan
November 25, 2002
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Security
The Internet
The Internet is NOT Secure
Firewall
Dedicated computer that governs
interaction between internal
network and the Internet
Encryption
Data Encryption Standard (DES)
November 25, 2002
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Disaster Recovery Plan
Restoring computer processing operations and
data files if operations are halted or files are
damaged by major destruction
November 25, 2002
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Backup
Why Backup?
“If you are not backing up your files
regularly, you deserve to lose them.”
Average user experiences loss once a year
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Backup
What Can Cause Data Loss?
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Incorrect software use
Input data incorrectly
Software may harm data
Hard disk malfunctions
Accidentally delete files
– “format c:” – oops…

Virus infection
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Viruses
 Illicit
instructions that pass themselves
on to other programs
– Benign
– Damaging to computer
 Digital
November 25, 2002
vandalism
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Viruses
Vaccine or antivirus software



Stops the spread of and eradicates the virus
Install software
Download signature files (ie, updates)
regularly
November 25, 2002
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Viruses

Retrovirus
– Fights the vaccine and may delete the antivirus
software

Costs
– Billions of dollars a year
– Aggravation to individual users
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Virus
Getting Infected




Executing the virus program
Booting from a diskette containing an infected
boot sector including accidentally leaving a “nonsystem disk” in the floppy drive
Downloading an infected file and executing it
Opening an infected e-mail attachment
– Including M$ Word documents

By viewing e-mail in some versions of Microsoft
Outlook
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Privacy
Where is my data?
 How is it used?
 Who sees it?
 Is anything private anymore?

Everything about you is in at least
one computer file
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Privacy
Monitoring by Web Sites
Records:


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City
Site you just left
Everything you do while on the site
Hardware and software you use
Click stream
– Series of clicks that link from site to site
– History of what the user chooses to view
November 25, 2002
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Privacy
Monitoring by Web Sites
Cookies


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Stores information about you
Located on your hard drive
Beneficial uses
– Viewing preferences
– Online shopping
– Secure sites retain password in cookie

Controversial use
– Tracking surfing habits for advertisers


Can set browser to refuse cookies or warn before
storing
Software available to manage cookies
November 25, 2002
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Word Processing
and
Desktop Publishing:
Printing It
Chapter 12
Word Processing
Software that assists in preparation and
printing of text documents
WYSIWYG 
What you see is what you get..
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Word Processing
Features

Insertion point – blinking cursor
– Where will the next typed character appear?

Scrolling
– Screen is window into document
– Brings other parts of document into view
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Word Processing
Features

Word wrap
– Automatically determines when to go to a new
line
• Justifies text automatically
– <Enter> to signal end of paragraph

Easy corrections
–
–
–
–
<Backspace> (deletes to the left)
<Delete>
(deletes to the right)
Undo
(<^Z> in M$ Word)
Insert vs. overwrite mode (<Insert>)
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Formatting Features
Adjust the physical appearance of the document


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Vertical centering
Line centering
Margins
– Default can be changed
– Automatic reformatting of text

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Tabs
Indentation
– Ordered, unordered lists
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Formatting Features

Justification
– Fully justified
– Left justified – ragged-right
– Right justified – ragged-left
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Line spacing
Bullets and Numbering
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Font
Weight – visual heaviness, thickness
 Style – visual design of letters
 Point size

– Point – 1/72 inch
– Measured from top of highest rising letter to
bottom of lowest descending letter
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Leading and Kerning

Leading
– Space between the lines of type
– Vertical measurement from base of one line to base of
next
– Measured in points

Kerning
– Space between characters
– Each font has a default kerning
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Ergonomics
Study of the interaction of
humans and machines
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Ergonomics
Types of Injury

Repetitive stress injury (RSI)
– Carpal tunnel syndrome
Eyestrain
 Back problems

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Ergonomics
Tips to Prevent Injury

Reduce glare
– Window glare
– Glare deflector
– No overhead lights

Avoid arm and wrist fatigue
– Place keyboard in low position
– Do not bend wrists
– Use a wrist rest
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Ergonomics
Tips to Prevent Injury
Support your lower back with the
appropriate seat
 Sit with your feet firmly on the floor
 Enlarge fonts (or overall document) while
editing then return them to their normal size

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Spreadsheets
and
Business Graphics:
Facts and Figures
Chapter 13
Why Use Spreadsheets?
Plan ahead (What if)
 Make the computer do the work
 See the results of change

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Electronic Spreadsheets
Labor Saving
Automatic recalculation
Change one value
 All dependent values are recalculated
 A single change can affect many
calculations

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Electronic Spreadsheets
Labor Saving
“What If” Analysis
The process of changing one or more spreadsheet values
and observing the resulting calculated effect
What if we reduce the price by 5%?
What if we buy a home and the mortgage rate
increases (or decreases) by .5%?
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Electronic Spreadsheets
Fundamentals

Screen
– Window into the spreadsheet
– Scroll using mouse or cursor-movement
keys

Rows and columns
– Row – number
– Column – letters
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Electronic Spreadsheets
Fundamentals

Cell
– Junction of a row and column
– Cell address (cell reference) – letter and
number
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Active cell (current cell)
– Highlighted with border or reverse video
– Can enter or edit data in active cell only
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Cell Contents

Label
– Descriptive text
about entries
– Not used for
calculations

Value
– Number
– May be used in
calculations
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Cell Contents
Formula
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Calculation instruction
=M5+N5+((O5+2)*0.3)+(P5*0.3)+(Q5*0.3)+R5

Contains
–
–
–
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Cell address
One or more arithmetic operators
Functions
Result appears in the cell containing the formula
Calculation appears in the formula bar
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Cell Contents
Functions
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Pre-programmed formulas
=AVERAGE(L5:L189)
Used in formulas in place
of operators
Common
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–
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SUM
AVERAGE
COUNT
MIN
MAX
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Cell Ranges
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November 25, 2002
Group of one or more
adjacent cells occurring in
a rectangular shape
Treated as a unit during an
operation
Indicate the upper-left and
lower-right cells of the
block
May be referenced in a
formula or function
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Formatting Features
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Column width
Row height
Headings
Number styles – commas, number of
decimals, dollar and percent signs
Appearance of data
– Justification
– Text font and style
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Excel features – HW#6

To use a function, type in formula bar/cell:
=SUM(A1:A4), result value shows in cell

To highlight cells based on their value
– Format->Conditional Formatting
• Set color, pattern, font, border
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To include row/column headings in printouts
– File->Page Setup -> Sheet
• Select Row and column headings
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Business Graphics
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Generate and sustain the interest of an audience
Make a lesson, report, or business document
more attractive
Help get a point across
Can reveal a trend that is lost in a column of
numbers
Presenter appears more prepared and organized
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Line Graphs
• Axis
• Plot area
• Data point
• Labels
• Titles
Shows trends or cycles over time
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Bar Graphs
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Comparisons
Rectangular area up to the height of the point being
plotted
Easy to absorb
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Pie Charts
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Proportions
Relationship between parts and whole
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One time period
Exploded pie chart
One wedge pulled slightly away from the pie
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Database Management:
Getting Data Together
Chapter 14
Computer Databases
Track information
 Allows higher productivity as a result of
better information

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Hierarchy of Data

Field
– Smallest meaningful unit of data
– Group of one or more characters that has a specific
meaning
– Used as “key” to locate records
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Record
– Set of fields containing all information known about one
entity
– Each record contains the same fields in the same sequence

File
– Collection of related records
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Sequential Access
Records are stored and accessed in order
 All records prior to the one requested
must be read
 Magnetic tape storage idea for this type of
file.

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Direct / Random Access
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Records are not physically stored in any order
Go directly to the record to read
– Hashing – apply a formula to the key to produce the
address of the record
– Collision – same address from different keys

Updating in place
– Read, change, and return a record to the same place
on disk
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DASD – Direct-Access Storage Device needed
– ie, Disk Drive
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Batch Processing
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Collect transactions into a transaction file and perform
periodic updates
Process
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Transactions are sorted by key field
Computer matches the master and transaction keys
Performs requested action – add, revise, delete
New master file created
Error report is printed
Master file only current immediately after processing
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Transaction Processing
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Processed upon request
Real-time – process handled immediately
Disk storage
– Direct access to desired record needed
• Immediate access to stored data
• Immediate updating of stored data
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Database Models
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Database Types
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–
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Relational
Object-oriented
Hierarchical
Network
Each type structures, organizes and uses
data differently
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Relational Database
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Organizes data into related tables
– (files)
Table consists of rows and columns
 Tables linked based upon a common field

– (key)
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Relational Database
Key

Primary key
– A field whose value uniquely identifies a record
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Foreign key
– Primary key of another table
– Used as link to other table
– May have duplicate values
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Data Integrity
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
Degree to which data is accurate and reliable
Integrity constraints – rules
– Acceptable values for a field (range, type)
– Primary key values
– Foreign keys

Integrity constraints must be enforced when data is
entered or data is unreliable
– GIGO (Garbage in, garbage out)
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DBMS
Database Management System
Basic functions
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Create a database
Enter data
Modify the data as required
Retrieve information from the database
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DBMS
Data Retrieval
Extracting the desired data from the
database
 Primary forms

– Queries
– Reports
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Query
Ask a question about the data
 Present criteria that selects data from the
database
 Results in smaller portion of the database

– Zero or more records can be retrieved

Query Language
– Prepare your query using English-like statements
– Proprietary query language in DBMS
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Concurrency Control
Databases are used concurrently by many
users
 Problem if several users attempt to update the
same record at the same time
 Record locking

– First user requests record
– Others are locked out for update
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Looking at the Data
Data Warehouses
Databases are designed to support ongoing
operations
 Data is captured from the db over time

– Summary form
– Regularly scheduled basis

May include data from external sources
– Ie, NYSE, weather, etc…
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Systems Analysis and Design:
The Big Picture
Chapter 15
Systems Analysis and Design
What is it?

Systems analysis
Process of studying an existing system to
determine how it works and how it meets user
needs

Systems design
Process of developing a plan for an improved
system, based upon the results of the systems
analysis
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SDLC
Systems Development Life Cycle
Preliminary investigation
 Analysis
 Design
 Development
 Implementation

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SDLC
Preliminary Investigation
Feasibility study / System survey
 Determine the problem
 Describe the problem
 Understand management decisions

– Organizational chart, informal hierarchy
Results in a rough plan and what to do
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SDLC
Analysis

Understand the existing system
– Gather data
– Analyze data

Establishes current system requirements
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SDLC
Design
Planning the new system
 Two phases

– Preliminary design
– Detail design
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SDLC
Preliminary Design
Create an overall plan
 Offer alternatives that meet requirements
 Explain differences
 Evaluate costs
 Build a prototype

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SDLC
Detail Design
Parts of detail design phase

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Output requirements
Input requirements
Files and databases
Systems processing
Systems controls and backup
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SDLC
Development

Programming
– Refine the design
– Detailed logic flowcharts and pseudocode

Testing
– Unit testing
– System testing
– Volume testing
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SDLC
Implementation






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
Converting to the new system
Training
Equipment conversion
File conversion
System conversion
Auditing
Evaluation
Maintenance
– Ongoing for the life of the system
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Programming Languages:
Telling the Computers
What to Do
Chapter 16
What is a Program?
A set of instructions written in a
programming language that tells the
computer what to do
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The Programming Process
Defining the problem
 Planning the solution
 Coding the program
 Testing the program
 Documenting the program

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The Programming Process
Defining the Problem
What is the input
 What output do you expect
 How do you get from the input to the
output

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The Programming Process
Planning the Solution

Algorithms
– Detailed solutions to a given problem
• Sorting records, adding sums of numbers, etc..

Design tools
– Flowchart
– Pseudocode
• Has logic structure, but no command syntax

Desk-checking
– Personal code design walk through

Structured walk through
– “Code walk through” – peer examination of source code
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The Programming Process
Coding the Program
Translate algorithm into a formal
programming language
 Within syntax of the language
 How to key in the statements?

– Text editor
– Programming environment
• Interactive Development Environment (IDE)
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The Programming Process
Testing the Program

Translation – compiler
– Translates from source module into object module
– Detects syntax errors

Link – linkage editor (linker)
– Combines object module with libraries to create
load module
– Finds undefined external references

Debugging
– Run using data that tests all statements
– Logic errors
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The Programming Process
Documenting the Program


Performed throughout the development
Material generated during each step
–
–
–
–
–
–
–
Problem definitions
Program plan
Comments within source code
Testing procedures
Narrative
Layouts of input and output
Program listing
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Language Generations
Low levels closer to binary
 High levels closer to human code
 Five Generations:

– Procedural Languages
• Machine language
• Assembly language
• High-level language – 3GL
– Nonprocedural Languages
• Very high-level language – 4GL
• Natural language – 5GL
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Machine Language

Written in strings of 0 and 1
– Displayed as hexadecimal
Only language the computer
understands
 All other programming languages
are translated to machine language
 Computer dependent

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Assembly Language

Mnemonic codes
– Add, sub, tst, jmp…
Names for memory locations
 Computer dependent
 Assembler translates from Assembly to
machine language

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3GL
High-Level Languages


1960s
Languages designed for specific types of
problems and used syntax familiar to the
people in that field
– FORTRAN: (FORmula TRANslator)
• Math
– COBOL: (COmmon Business Oriented Language)
• Business

Compilation translates from high-level
language to machine language
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4GL
Very High-Level Languages
Programmer specifies the desired results;
the language develops the solution
 Ten times more productive with a 4GL
than a procedural language
 Query Languages

– Retrieve information from databases
– Easy to learn and use
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5GL
Natural Languages



Resemble natural or
spoken English
Translates human
instructions into
code the computer
can execute
Commonly used by
non-programmers to
access databases
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Third Generation Languages
Traditional Programming
 Describe
data
 Describe procedures or operations
on that data
 Data and procedures are separate
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Third Generation Languages

FORTRAN (FORmula TRANslator)
– 1954
– Represent complex mathematical formulas
– C/C++ has replaced FORTRAN

COBOL (Common Business Oriented Language)
–
–
–
–
1959
Business
Large complex data files
Formatted business reports
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Third Generation Languages

BASIC (Beginners All-purpose Symbolic Instruction
Code)
– 1965
– Popularity grew with PC popularity (1970s)
– Easy to learn
– Used little memory
– Bill Gates beginnings.. M$ Basic

RPG (Report Program Generator)
– 1965
– Report generation – quickly creates complex reports
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Third Generation Languages

C
– 1972
– Efficient code – the language of UNIX
– Portability

C++
– Enhancement of C (Object Oriented)

M$ Visual Basic
–
–
–
–
1987
Create complex user interfaces
Uses standard Windows features
Event-driven – user controls the program
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Third Generation Languages
Java
Cross-platform
 Java Virtual Machine (JVM)

– Sits on top of computer’s regular platform
– Translates compiled Java code into instructions
for the specific platform

Applets
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Javascript & Power Point

From HW #5
– Something related to example file

From Final Project – Power Point
– Something from command set
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