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CS110: PROGRAMMING
LANGUAGE I
Lecture 1: Introduction Computer Science
Department
1
Lecture Contents
Computer Science Department
Course Info.
Elements of a Computer system.
Evolution of programming languages
The code Life Cycle
2
Course info
Website
cs110spr14.wordpress.com
Books
Course plan
Assessment methods and grading
Labs and practical assignments
Practical exam
3
[1]
[2]
Elements of a Computer System
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Hardware
Software
Computer
Hardware
5
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Memory Unit 6
Ordered sequence of cells or locations
Stores instructions and data in binary
Types of memory
Read-Only Memory (ROM)
Random Access Memory (RAM)
Bit: A binary digit 0 or 1.
A sequence of eight bits is called a byte.
Binary Data 7
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ASCII Code 8
Every letter, number, or special symbol (such as * or {) on your keyboard is encoded as a sequence of bits, each having a unique representation.
The most commonly used American Standard Code for Information Interchange (ASCII).
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Central Processing Unit (CPU)
Executes stored instructions
Arithmetic/Logic Unit (ALU)
Performs arithmetic and logical operations
Control Unit
Controls the other components
Guarantees instructions are executed in sequence
Input and Output Devices 10
Interaction with humans
Gathers data (Input)
Displays results (Output)
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Software
loads first when you turn on your PC
Also called the operating system.
The operating system monitors the overall activity of the computer and provides services, such as memory management, input/output activities, and storage management.
perform specific tasks
Examples :
Word processors
spreadsheets, and
games
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System programs Application programs
Both operating systems and application programs are
written in programming languages.
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Are Computers Intelligent?
Do we really need to be involved in programming
computers?
They have beaten world chess champions.
They help predict weather patterns.
They can perform arithmetic quickly.
So, a computer has an IQ of _____.
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What is Computer Programming?
Planning or scheduling a sequence of steps for a
computer to follow to perform a task.
Basically, telling a computer what to do and how to
do it.
A program:
A sequence of steps to be performed by a computer.
Expressed in a computer language.
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Computer Languages
A set of
Symbols (punctuation),
Special words or keywords (vocabulary),
And rules (grammar)
used to construct a program.
Evolution of Programming Languages
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Languages differ in
Size (or complexity)
Readability
Expressivity (or writability)
"Level"
closeness to instructions for the CPU
Machine Language 16
Binary-coded instructions
Used directly by the CPU
Lowest level language
Every program step is ultimately
a machine language instruction
10010110
11101010
00010010
10101010
10010110
11101010
11111111
01010101
10101101
2034
2035
2036
2037
2038
2039
2040
2041
2042
Address Contents
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Assembly Language
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Each CPU instruction is labeled with a mnemonic.
Very-low level language
Almost 1 to 1 correspondence with machine language
Assembler: A program that translates a program written in
assembly language into an equivalent program in machine
language.
Mnemonic Instruction
ADD 10010011
MUL X,10
ADD X,Y
STO Z,20
SUB X,Z
Sample Program
Examples of Instructions in Assembly Language and
Machine Language 18
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High-Level Languages
Closer to natural language
Each step maps to several
machine language instructions
Easier to state and solve
problems
Compiler: A program that
translates a program written
in a high-level language into
the equivalent machine
language.
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Examples of High-Level Languages
Language Primary Uses
Pascal Learning to program
C++ General purpose
FORTRAN Scientific programming
PERL Web programming, text processing
Java Web programming, application
programming
COBOL Business
The java Language
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source
program.
Saved in File
ClassName.ja
va
The Code life Cycle!!
Edit compile run
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Processing a java program 23
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IDE
23-Jan-14 Computer Science Department
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The programs that you write in Java are typically
developed using an integrated development
environment (IDE).
Text book
[1] chapter 1 (pages 1-13)
That’s all for this week 25
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