CSC101_L1 - Intro to Computer Systems

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CSC 101.

INTRODUCTION TO

COMPUTER SCIENCEAY 2014-2015 (Term 2)



Grading System

Exam 60 %Laboratory Exercise/Quiz 25HW/SW 10Attendance 5

Main References:• JAVA TM Programming: From Problem Analysis to Program Design by D. S. Mali• JAVA TM How to Program, 7 th ed by Deitel

Passing Rate: 60%No Removal Exam



LECTURE 1

INTRODUCTION TO COMPUTERSYSTEMS



Lecture OutlineWhat is a computer?

Hardware and SoftwareComponents of a Computer SystemStarting a ProgramNetworksLanguage of a ComputerEvolution of Computer LanguageProgrammingProgramming Methodologies



What is a computer?a general purpose device that can beprogrammed to carry out a set of arithmeticor logical operations automatically

a complex system consisting of bothhardware and software components

Variations:

embedded computers

calculator, ATM, printer, videogame console

personal computer (aka desktop and homecomputer), laptop, portable, notebookcomputer

PDA

Mainframe or Supercomputer



Hardware vs Software

Hardware Software

Definition

• Devices that are required to storeand execute (or run) thesoftware.

• collection of instructions thenables a user to interact wcomputer

• a program that enables acomputer to perform a spectask, as opposed to the phy

components of the system

Types • Input, storage, processing,

control, and output devices.

• System software, Utility soand Application software.

Examples

• CD-ROM, monitor, printer, videocard, scanners , label makers,routers , and modems.

• Operating systems, driversAcrobat, Internet Explorer Microsoft Word , Microsof



Components of a Computer System

I/O CPU

Memory

System

Bus

Computer




Registers AL

ControlUnit

Internal

Bus

CPU

I/O CPU

Memory

SystemBus

Computer




MemoryMain/Primary Secondary• closely connected to the

processor.• stored data are quickly and

easily changed.• holds the programs and data

that the processor is activelyworking with.

• interacts with the processormillions of times per second.

• needs constant electric powerto keep its information.

• connected to main memorythrough the bus and acontroller.

• stored data are easily changed,but changes are slowcompared to main memory.

• used for long-term storage ofprograms and data.

• before data and programs canbe used, they must be copiedfrom secondary memory intomain memory.

• does not need electric powerto keep its information.



Starting a Program1. The user asks to run an application.

2. The OS determines the name of the application.

3. The OS finds the files on the hard disk where the application and its data arestored.

4. The OS finds an unused section of main memory that is large enough for theapplication.

5. The OS makes a copy of the application and its data in that section of mainmemory.

6. The OS sets up resources for the application.

7. Finally, the OS starts the application running.



Computer Networks

Network

consists of two or more computers connected so that they canexchange data and programs

through network interface card



Computer NetworksInternet

a global system of interconnected computer networks that use thestandard Internet protocol suite (TCP/IP) to link several billion deviceworldwide

carries an extremely large number of network services, including theWorld Wide Web, electronic mail, Internet phone, audio, video and fil

transfer servicesWorld Wide Web

a global set of documents, images and other resources, logicallyinterrelated by hyperlinks



Language of a Computer

Electrical SignalsAnalog

continuous waveforms used to represent things, such as sound

Digitalrepresent information with a sequence of 0s and 1s

more reliable carriers of information than analog signals and can be copied froone device to another with exact precision

Machine Language is digital.



Language of a Computer

binary digit or bit

digit 0 or 1

binary code or binary number

sequence of 0’s and 1’s

byte

8 bits

American Standard Code forInformation Interchange (ASCII)

most commonly used

encoding scheme on personalcomputers



Evolution of Programming LanguagesMachine Language

provides program instructions in bitseven though most computers perform the same kinds of operations, the designers of differCPUs sometimes choose different sets of binary codes to perform those operations

Ex: user wants to use the equation c = a + b

100100 010001

100101 010010

100010 010011

a 010001

b 010010

c 010011

load 100100

addition 100101

store 100010



Assembly Language

developed to make the programmer’s job easieran instruction is an easy-to-remember form called a mnemonic

LOAD a

ADD b

STOR c



High-Level Language

closer to spoken languages

Basic, FORTRAN, COBOL, Pascal, C, C++, and Java

Ex:

c = a + b;



Processing a JAVA

program



Programming

a process of problem solving1. analyzing a problem

2. outlining the problem requirements

3. designing steps (algorithm)

Algorithm

a step-by-step problem-solving process in which a solution is arrived at infinite amount of time



programming process



Ex: Design an algorithm to find the perimeter and area of arectangle

1. Get the length of the rectangle.

2. Get the width of the rectangle.

3. Find the perimeter using the following equation:

perimeter = 2*(length + width)

4. Find the area using the following equation:

area = length*width



Programming Methodologies

Structured Programming

problem is divided into smaller subproblems then each subprobis analyzed and a solution for the subproblem is obtained.solutions to all the subproblems are then combined to solveoverall problem

also known as top-down design, bottom-up design, steprefinement, and modular programming



Programming Methodologies

Object-Oriented Programming

first step in the problem-solving process is to identifycomponents called objects , which form the basis of the sand to determine how these objects interact with one another



ReviewTrue or False:

1. Assembly language is the language that uses mnemonics for its instructions.

2. The arithmetic operations are performed inside CPU and, if an error is found, it outputs logical errors.

3. A Java compiler is a program that translates a Java program into bytecode.

4. Bytecode is the machine language of the JVM.

5. The CPU stands for command performing unit.

6. RAM stands for readily available memory.7. A program written in a high-level programming language is called a source program.

8. The operating system is the first program loaded into the computer when the power is tuon.

9. The first step in the problem-solving process is to analyze the problem.



References JAVATM Programming: From Problem Analysis to Program Design by D. S. Malik

JAVATM How to Program, 7th ed by Deitel

Computer. http://www.computerhope.com/jargon/c/computer.htm

Top 10 Most Popular Programming Languages. http://www.english4it.com/readin

Introduction to Computer Science using Java.http://chortle.ccsu.ed u/CS151/cs151java.html

Introduction to Computer Science.

http ://en.wikiversity.org/wiki/Introduction_to_Computer_ScienceHardware vs Software. http://www.diffen .com/difference/Hardware_vs_Software

http://www.computerhope.com/jargon/c/computer.htm

http://www.english4it.com/reading/40

http://chortle.ccsu.edu/CS151/cs151java.html


http://en.wikiversity.org/wiki/Introduction_to_Computer_Science


http://www.diffen.com/difference/Hardware_vs_Software





http://www.english4it.com/reading/40

http://www.computerhope.com/jargon/c/computer.htm

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CSC101_L1 - Intro to Computer Systems