1. Exposure Java 2015 Pre-AP®CS Edition Chapter 1 Slides
Introduction to Computer Science
PowerPoint Presentation
created by:
Mr. John L. M. Schram
and Mr. Leon Schram
Authors of Exposure Java

2. Section 1.1
Learning the
Exposure Way

3. The “Nothing is Obvious” Story
Imagine a young boy in the Amazon jungles.
This boy has always lived in the jungle without
any modern conveniences. He has never been
in a city; he has never seen a television nor seen a book.
Now imagine that for some unknown reason this young boy travels to Colorado in the Winter time. The little boy stands in a yard somewhere and watches the snow with bewilderment. He is astonished; he does not understand what is falling from the sky.
Another little boy, about the same age, from Colorado, looks at the boy's behavior. The Colorado boy is confused, why is the boy acting so odd?
Obviously it is snowing, so what is the big deal?

4. Corn Flakes & Iced Tea
Most Americans consider it "obvious" that cold milk is poured on corn flakes. However, in Europe, everybody knows you put warm milk on your cereal.
Most Europeans consider it "obvious" that Tea is to be served warm, preferably hot. They are completely baffled when Texans actually put ICE in their Tea.

5. Section 1.2
The Exposure
Equation

6. Bewilderment + Exposure = Obvious
The Exposure Equation
Bewilderment + Exposure = Obvious

7. Exposure in Extracurricular Activities
Drill team performance
Half-time band show
Football Team blocking
Basketball free throws
Baseball batting

8. The Curious Exposure Discrepancy
Students recognize that only continuous practice will result in a good showing at a brief performance or brief competition
Many of the same students barely read or practice a topic once for an academic subject.
It appears that preparation for a known, short performance requires practice, but preparation for life receives only minimal effort from many students.

9. Section 1.3
Getting
Started

10. Computer Fundamentals
Getting started with computer science is none too easy.
The course that you are taking assumes that this is your first formal computer science course.
Furthermore, it is also assumed that you have no knowledge of programming.
If you do know some programming, fine, but it is not any kind of a prerequisite.
This means that we should start at

11. Section 1.4
How Do
Computers Work?

12. Three Ways Where Computers Beat People
Computers are faster.
Computers are more accurate.
Computers do not forget.

13. Section 1.5
Messages with
Morse Code

14. Morse Code

15. Section 1.6
Electronic
Memory

16. Electronic Memory
off on 1

17. Decimal (Base-10) Number System
The number system that we use is called the decimal number system or base-10.
It is called “base-10” because it has 10 digits (0 – 9).
Rumor has it that people developed a base-10 system, because of our ten fingers.
Consider the base-10 number 2,345,678
106
105
104
103
102
101
100
1,000,000
100,000
10,000
1,000 10 1 2 3 4 5 6 7 8

18. 0-31 in Bases 10 & 2
base-10
base-2 16
10000 1 17
10001 2 10 18
10010 3 11 19
10011 4
100 20
10100 5
101 21
10101 6
110 22
10110 7
111 23
10111 8
1000 24
11000 9
1001 25
11001
1010 26
11010
1011 27
11011 12
1100 28
11100 13
1101 29
11101 14
1110 30
11110 15
1111 31
11111

19. Binary (Base-2) Number System
The number system used by computers is the binary number system or base-2.
Only the digits 0 and 1 are used.
Remember that modern computers use electricity, which is either on or off. 1 means on. 0 means off.
Consider the base-2 number
Can you tell that this is equal to the base-10 number 65? 27 26 25 24 23 22 21 20
128 64 32 16 8 4 2 1

20. Three Combinations of 8 Light Bulbs
(base-2) =
65 (base-10) or char A 1
(base-2) =
66 (base-10) or char B 1
(base-2) =
67 (base-10) or char C 1

21. Bits, Bytes & Codes
Bit is a binary digit that is either 0 (off) or 1 (on)
1 Byte = 8 bits
1 Nibble = 4 bits (½ a byte)
1 Byte has 28 or 256 different numerical combinations.
2 Bytes has 216 or 65,536 different numerical combinations.
ASCII uses one byte to store one character.
Unicode uses two bytes to store one character.

22. Section 1.7
Memory and
Secondary Storage

23. Motherboard & Computers Chips
The main board with all the primary computer components. Has several computer chips attached:
Read Only Memory (ROM)
This chip stores permanent information for the computer.
Random Access Memory (RAM)
This chip stores temporary information for the computer.
Central Processing Unit (CPU)
This chip is the “brains” of the computer.

24. Note: Technically, a kilobyte is exactly 210 or 1024 bytes.
Measuring Memory KB
Kilo Byte
1 thousand bytes
1,000 MB
Mega Byte
1 million bytes
1,000,000 GB
Giga Byte
1 billion bytes
1,000,000,000 TB
Tera Byte
1 trillion bytes
1,000,000,000,000 PB
Peta Byte
1 thousand terabytes
1,000,000,000,000,000 EB
Exa Byte
1 million terabytes
1,000,000,000,000,000,000 ZB
Zetta Byte
1 billion terabytes
1,000,000,000,000,000,000,000 YB
Yotta Byte
1 trillion terabytes
1,000,000,000,000,000,000,000,000
Note: Technically, a kilobyte is exactly 210 or 1024 bytes.

25. Secondary Storage Devices
Since RAM is lost when the computer is turned off, files must be saved to some secondary storage device for later use.

26. Section 1.8
Hardware &
Software

27. Hardware Hardware refers to physical pieces of computer equipment.
This included the main computer system unit, as well as all of the peripherals (things that plug into the computer.)

28. Software Software provides instructions to a computer.
The most important aspect of this course is to learn how to give correct and logical instructions to a computer with the help of a programming language.
Software falls into two categories:
System Software
Application Software.
The major Operating Systems are Windows, UNIX, Linux and the MAC OS. These are all examples of System Software.
Applications Software runs an application on a computer.
Examples of Application Software are Word, Excel, PowerPoint, Video Games, and the very programs that you will write in this course.

29. Section 1.9
A Brief History
Of Computers

30. The First Era Counting Tools
A long time ago some caveman must
have realized that counting on fingers
and toes was very limiting.
They started making marks on rocks,
carving notches in bones and tying
knots in rope.
Eventually, mankind found more practical ways to not only keep track of large numbers, but also to perform mathematical calculations with them.

31. The Abacus 3000 B.C.
The Abacus was originally invented in the Middle Eastern area. This rather amazing computing device
is still very much used in many Asian countries today.

32. Napier's "Bones" 1617 A.D.
John Napier used some bones marked with special scales to simplify arithmetic by using addition for multiplication.

33. The Slide Rule 1622 William Oughtred created the slide rule.
This device allows sophisticated mathematical calculations and was used for centuries until it was replaced by the scientific calculator in the 1970s.

34. The Second Era Gear Driven Devices
More complicated tasks required more complicated devices. These devices would have rotating gears.
Since they did not use electricity, they would require some form of manual cranking in order to function.
One problem with devices that have moving parts is that they wear and break.

35. Numerical Calculating Machine 1642
Blaise Pascal built the Pascaline. This was the first numerical calculating machine. The inner workings of this device are similar to the tumbler odometers found in old cars. It could perform addition and subtraction.
A version of this device was still being used in the 1970s!

36. Jacquard's Loom 1805
Joseph Jacquard invented a special loom that would accept special flexible cards that are punched with information in such a manner that it is possible to program how cloth will be weaved. It is one of the first examples of programming.

37. “The Father of Computers”
Analytical Engine 1833
Charles Babbage invented a machine that can read instructions from a sequence of punched cards. This became the first general purpose computing machine.
“The Father of Computers”

38. Programming 1842 “The Mother of Programming”
Ada Byron, the Countess of Lovelace, was Charles Babbage’s assistant. She knew his device required instructions – what we would today call programs or software. So, over 170 years ago, she started designing computer programs. In so doing she developed certain programming ideas and techniques that are still used in modern programming languages today.
“The Mother of Programming”
“The World’s First Programmer”

39. The Third Era Electro-Mechanical Devices
The term electro-mechanical device means the device uses electricity, but still has moving parts. These devices are not yet “fully electronic”.
Since they do use electricity, the manual cranking is no longer needed. Since they still have moving parts, they still break down easily.

40. Tabulating Machine 1889
Herman Hollerith invented a tabulating machine that records statistics for the U.S. Bureau of Census.
The 1880 census took 8 years to tabulate by hand.
With this punch-card tabulating machine, the 1890 census was tabulated in just 1 year.

41. Tabulating Machine Company 1896, 1911, 1924
In 1896, Herman Hollerith founded the Tabulating Machine Company. In 1911, this firm merged with three others to form the Computing Tabulating Recording Company.
In 1924, the company was renamed International Business Machines Corporation.

42. Differential Analyzer 1931
Harold Locke Hazen and Vannevar Bush, from MIT,
built a large scale computing machine capable of solving differential equations.
In 1934 a model was made at Manchester University by Douglas Hartree and Arthur Porter out of an erector set.
It was less expensive, but still "accurate enough for the solution of many scientific problems".

43. Z
Konrad Zuse builds an electro-mechanical computer capable of automatic computations in Germany during World War II.
It was the first functional,
programmable, fully
automatic digital computer.
The Z3 was destroyed in
1943 during the Allied
bombing of Berlin.
Some credit Konrad Zuse as the “inventor of the computer”

44. Mark-I 1944
This electro-mechanical calculator was 51 feet long and 8 feet tall. It was the first machine that could execute long computations automatically. These computations could involve several numbers, each up to 23 digits in length.

45. Grace Hopper
Grace Hopper, then a Navy Lieutenant, was one of the first programmers of the Mark-I. She would make so many contributions to the world of computer science that the United States Congress allowed her to stay in the Navy past mandatory retirement age. She finally retired as an Admiral in 1986 at the age of 79.

46. Mark-II
On September 9, 1942 the Mark-II stopped working. A technician found and removed moth from one of its relays. This was the first literal computer bug. The actual moth is currently on display at the San Diego Computer Museum.
Shortly after this happened, Grace Hopper made the term “debugging” popular.

47. The Fourth Era Fully Electronic Computers with Vacuum Tubes
This is often referred to as
“The First Generation of Computers”.
Fully electronic computers do not rely on moving parts. This makes them faster and more reliable.
The vacuum tubes used at the time still had their share of drawbacks.
They were big and bulky.
They would get hot and burn out.

48. ABC 1940 The Atanasoff- Berry Computer
The very first electronic digital computer, the ABC, was invented by John Atanasoff and Clifford Berry at Iowa State University.
This was not a “general purpose computer”, nor was
it programmable.
It was specifically designed to solve systems of linear equations.
The Atanasoff-
Berry Computer

49. Colossus
This was the first electronic digital computer that was somewhat programmable. It was designed by an engineer named Tommy Flowers.
A total of 10 Colossus computers were made.
They were used by code breakers in England to help decrypt the secret coded messages of the Germans during World War II.

50. ENIAC
The ENIAC (Electronic Numerical Integrator and Computer) was the first electronic general purpose computer.
It was invented by John Mauchly and J. Presper Eckert. This computer is twice the size of the Mark-I, contained 17,468 vacuum tubes, and is programmed by rewiring the machine.
The cost:
$500,000

51. ENIAC
The ENIAC was capable of performing 385 multiplication operations per second.
In 1949, it was the first computer used to calculate PI.
The press called it “The Giant Brain.”

52. EDVAC
The EDVAC (Electronic Discrete Variable Automatic Computer) was the successor to the ENIAC.
The main improvement was that it was a Stored Program Computer.
This meant is could store a program in electronic memory. (about 5½ kilobytes).

53. UNIVAC I
The UNIVAC I (UNIVersal Automatic Computer) was the world’s first commercially available computer.
The computer became famous when it correctly predicted the results of the 1952 presidential election.

54. The Fifth Era Computers with Transistors or Integrated Circuits
The invention of the transistor began
“The Second Generation of Computers”.
The University of Manchester made the first transistor computer in Transistors have certain key advantages over vacuum tubes.
They are much smaller.
They do not get hot and burn out.

55. Integrated Circuit
Jack Kilby, of Texas Instruments, in Richardson, Texas, developed the first integrated circuit which has multiple transistors on a tiny thin piece of metal, called a chip. Jack Kilby used germanium.
Six months later Robert Noyce came up with his own idea for an improved integrated circuit which uses silicon.
He is now known as “The Mayor of Silicon Valley”.
Both gentlemen are credited
as co-inventors of the
integrated circuit.
This began “The Third
Generation of Computers”.
As technology improved,
we developed the ability
to put billions of transistors
on a tiny microchip.

56. Video Games 1958/1962 The first video game was called Tennis for Two.
It was created by William Higinbotham and played on a Brookhaven National Laboratory oscilloscope.
Since this game did not use an
actual computer monitor, some
give credit for the first video game
to SpaceWar! written by
Stephen Russell at MIT in 1962.

57. IBM System/
IBM creates a family of computers which cover a complete range of applications. These computers work for both the math community and the business community. All computers in this series are compatible, but sell for different prices based on their speed. System/360 is responsible for establishing a number of industry standards including the 8 bit byte.

58. Apple II 1977
The Apple Computer Company was created and introduced the Apple II Personal Computer.
It became the first commercially successful personal computer.

59. VisiCalc 1979
Dan Bricklin created VisiCalc, a spreadsheet program, which became the first wide spread software to be sold.

60. WordStar 1979
MicroPro releases WordStar, which became the most popular word processing program.

61. IBM PC 1981
IBM's entry into the personal computer market gave the personal computer a serious image as a true business computer and not some sophisticated electronic game playing machine.

62. MS-DOS 1981
Microsoft, an unknown little company run by Bill Gates, agreed to produce the operating system for the IBM Personal Computer and became a company larger than IBM.

63. Compaq Portable
The Compaq Portable is known for two things. It was the first portable computer. By today’s standards it was nothing like a modern laptop. The 28 pound computer was the size of a small suitcase. Compaq was also the first computer to be 100% compatible with an IBM PC.

64. The Macintosh 1984
The "Mac" was the first commercially successful computer with the mouse/windows technology.
The mouse technology was already developed earlier by Xerox Corporation.

65. Windows
The first Windows operating system was actually an Operating Environment which acted as a front while MS-DOS was running in the background.

66. Windows
Microsoft introduces Windows 95, which uses an operating system similar to the Macintosh computer.

67. Professional / Power User Editions
Windows Versions
Version
Home Editions
Professional / Power User Editions 1
Windows 1.0 – 3.1
Windows NT 3.1 2
Windows 95
Windows NT 3.51 3
Windows 98
Windows NT 4.0 4
Windows Millennium
Windows 2000 5
Windows XP Home Edition
Windows Home Server
Windows XP Professional Edition
Windows Server 2003
Windows Server 2003 R2 6
Windows Vista
Windows Server 2008 7
Windows 7
Windows Home Server 2011
Windows Server 2008 R2 8
Windows 8, 8.1
Windows Phone 8
Windows RT
Windows Server 2012
Windows Server 2012 R2 9
Windows 10?

68. Tianhe-2 Supercomputer 2013
As of June 2013, China’s Tianhe-2 is the fastest computer in the world. It can perform 33,860,000,000,000,000 floating point operations in 1 second.
That is 88 TRILLION times as fast as the ENIAC!

69. Section 1.10
What is
Programming?

70. Program Definition
A program is a sequence of instructions that makes a computer perform a desired task.
A programmer is a person who writes a program for a computer.

71. Programming Languages
Section 1.11
A Brief History of
Programming Languages

72. Programming in Machine Code
Programming in Machine Language a.k.a. Machine Code means you are directly manipulating the 1s and 0s of the computer’s binary language.
In some cases, this means
you are manipulating the
wires of the machine.
In other cases, you are flipping switches on and off.
Even if you had the ability to “type” the 1s and 0s, machine language would still be incredibly tedious.

73. Assembly Language & the EDSAC 1949
Assembly Language was first introduced by the British with the EDSAC (Electronic Delay Storage Automatic Computer).
EDSAC had an assembler called Initial Orders which used single-letter mnemonic symbols to represent different series of bits.
While still tedious, entering a program took less time and fewer errors were made.

74. “Amazing Grace”
In the 1940s, Grace Hopper did not like the way we were programming computers. There had to be a better way. The whole reason computers were invented in the first place was to do tedious. It should be possible to program a computer using English words instead of 1s and 0s.
Grace Hopper wrote the first compiler (a type of translator) in 1952 for the language A-0. This paved the way for the other languages that followed. Many of these were also created in part or in whole by Grace Hopper.
Her immeasurable contributions to computer science have earned her the nickname “Amazing Grace”. The Cray XE6 Hopper supercomputer and the USS Hopper Navy destroyer are also named after her.

75. Types of Languages Low-Level Languages
Languages that function at, or very close to 1s and 0s.
Powerful, but very difficult.
Examples: Machine Language, Assembly Language
High-Level Languages
Languages that use English-like words as instructions.
Easier, but less powerful.
Examples: BASIC, Pascal, COBOL, FORTRAN, PL/I, Java
Very High-Level Languages
Languages that use clickable pictures as instructions.
Example: Lego Mindstorms NXT

76. Computer Translators
A translator (compiler or interpreter) translates a high-level language into low-level machine code.
A compiler translates the entire program into an executable file before execution.
An interpreter translates one program statement at a time during execution.

77. FORTRAN 1957 The first successful high-level programming language.
FORTRAN stands for FORmula TRANslation
Developed by a team of IBM programmers
for mathematicians, scientists and
engineers.
While good for number crunching,
FORTRAN could not handle the record processing required for the business world.

78. LISP 1958 LISP (LISt Processing) was designed by John McCarthy at MIT.
It is known for being one of the languages specifically designed to help develop artificial intelligence.
LISP introduced several important programming concepts which are used in modern programming languages today.

79. COBOL
Created (largely by Grace Hopper) for the business community and the armed forces.
COBOL stands for
COmmon Business Oriented Language.
COBOL became extremely successful when the Department of Defense adopted COBOL as its official programming language.

80. FORTRAN vs. COBOL s
In the early 1960s computer design was not yet standardized and was strongly influenced by programmers’ languages of choice.
FORTRAN programmers wanted computers that were suited for number crunching.
COBOL programmers wanted computers that were suited for record handling.
Companies like IBM would have different models for “FORTRAN programmers” and “COBOL Programmers”.
In 1964, the IBM System/360 family of computers standardized hardware and was suitable for both.

81. PL/I 1964 PL/I stands for Programming Language 1.
After IBM standardized hardware with System/360, they set out to standardize software as well by creating PL/I.
This language combined all of the number crunching features of FORTRAN with all of the record handing features of COBOL.
The intention was that this language would be
“everything for everyone”.
The reality was that the FORTRAN programmers did not like the COBOL features, the COBOL programmers did not like the FORTRAN features, and new programmers found the language too complex to learn.

82. BASIC
Tom Kurtz and John Kemeny created BASIC (Beginners All-purpose Symbolic Instruction Code) at Dartmouth College.
Their intention was that a simple language would give non-math and non-science majors the ability to use computers.
The use of BASIC became
widespread when personal
computers hit the market.
The first was the Altair in 1976.
BASIC required little memory, and it was the only language that could initially be handled by the first personal computers.
The Altair was shipped with Altair BASIC a.k.a. Microsoft BASIC.

83. Pascal
College professors did not like BASIC because it did not teach proper programming structure.
Instead, it taught quick-and-dirty programming.
Niklaus Wirth decided to create a language specifically for the purpose of teaching programming.
He named this new language Pascal after Blaise Pascal.
Unlike PL/I, Pascal is a very lean language.
It has just enough of both the math features of FORTRAN and the record handling features of COBOL to be functional.
In 1983, the College Board adopted Pascal as the first official language for the AP® Computer Science Exam.

84. C
In 1966, BCPL (Basic Combined Programming Language) was designed at the University of Cambridge by Martin Richards.
This language was originally intended for writing compilers.
In 1969, Ken Thompson, from AT&T Bell Labs, created a slimmed down version of BCPL which was simply referred
to as B.
In 1972, an improved version of B was released.
This was called C.
In 1973, C was used to rewrite the kernel for the UNIX operating system.

85. C
As computer programs grew more complex a new, more powerful, and more reliable type of programming was needed. This lead to the development of
Object Oriented Programming (OOP).
Bjarne Stroustrup wanted to create a new language that uses OOP, but did not want programmers to have to learn a new language from scratch. He took the existing, very popular language C and added OOP to it.
This new language became C++.
In 1997, C++ replaced Pascal as the official language for the AP® Computer Science Exam.

86. Medium-Level Languages
C and C++ are sometimes considered to be medium-level languages.
This is because they have the English commands of a high-level language as well as the power of a low-level language.
This made C, and later C++, very popular with professional programmers.

87. Java 1995 Released in 1995 by Sun Microsystems.
Java is a Platform Independent Language.
Platform Independence means that the language does not cause problems as programs are transported between different hardware and software platforms.
Unlike C++, were OOP is optional, Java requires you to use OOP which caused many universities to adopt it.
For this reason, in 2003, Java replaced C++ as the official language for the AP® Computer Science Exam.
In 2010, Oracle acquired Sun Microsystems.
Java has continued to improve in the same manner as when Sun Microsystems owned the company.

88. Lego Mindstorms NXT 2006 A new kind of programming has
come about that is very high-level.
In this style of programming, the
programmers can click on different
blocks. Each block performs a different task.
By creating a sequence of these blocks, you
can program a computer.
In 1998, the Lego Corporation created their first point-and-click language for use with their Lego Mindstorms robots.
In 2006, they released their next language, and decided to call it NXT. In 2009, NXT 2.1 was released.

89. What We Use
During this school year, we will be learning Java. At some schools one or more Lego NXT labs are sometimes done before a chapter to introduce a topic.

90. Section 1.12
Networking

91. SneakerNet Early personal computers were not networked at all.
Every computer was a stand-alone computer.
Some computers were hooked up to printers and many others were not.
If you needed to print something, and you were not directly connected to a printer, you saved your work to a floppy disk, put on your sneakers, and walked to the printing computer.
Sharing files was done in the same way.

92. Peer-To-Peer Networks
The first practical networks for personal computers were peer-to-peer networks.
These are small groups of computers with a common purpose all connected to each other.
These types of networks were frequently called Local Area Networks or LANs.
Initially, the networks were true peer-to-peer networks.
This means that every computer on the network was equal.

93. Client-Server Networks
A server is a special computer that is connected to the LAN for one or more purposes.
It services the other computers in the network which are called clients.
Servers can be used for printing, logon authentications, permanent data storage and communication.
Server
Client
Client
Client

94. The Department of Defense
The Internet has existed since the 1960s and has its origins in the "Cold War." During the Cold War there was a major concern about the country being paralyzed by a direct nuclear hit on the Pentagon.
A means of communication had
to be created that was capable
to keep working regardless of
damage created anywhere.
This was the birth of the Internet.
The Internet has no central
location where all the control
computers are located.
Any part of the Internet can be
damaged and all information will
then travel around the damaged area.
Many people confuse the
World Wide Web with the Internet.
WWW came out in the 1990s
and is a PART of the Internet.

95. The Modern Internet
Normally, businesses and schools have a series of LANs that all connect into a large network called an Intranet.
An Intranet behaves like the Internet on a local business level.
This promotes security, speed and saves cost.
Now the moment a school, a business, your home, wants to be connected to the outside world and giant world-wide network known as the Internet, you have access to millions of lines of telecommunications.
This will cost money and every person, every school, every business, who wants this access needs to use an Internet Service Provider or ISP.
You pay a monthly fee to the ISP for the Internet connection.
The amount of money you pay depends on the speed of your Internet connection.