Introduction to Computer Programming

Lesson 1

What is a Computer System?

• A computer system is made up of two parts: Hardware and Software

• Hardware is the Physical Equipment

• Software is a collection of programs (or computer instructions) which allow the hardware to function

Hardware

• Hardware can be broken into five groups:

1 CPU (Central Processing Unit)

2 Primary Storage (or main memory)

3 Secondary Storage (such as a hard disk)

4 Input Devices (like a keyboard)

5 Output Devices (like a monitor or printer)

Software

• Software can be broken into two groups:– System Software– Application Software

Types of Computer Environments

• Personal Computer (PC)

• Timeshare

• Client/Server

What is a Computer Program?

• A computer program is generally designed to solve a problem

• A problem exists when what you have is not the same as what you want

• What you have is called DATA• What you want is called INFORMATION• A Computer Program manipulates data to

produce information

What does a Computer Programmer do?• A computer needs very simple step-by-step instructions to

function• A person can usually solve problems in quick and complex

ways• A programmer creates solutions to problems• A programmer then breaks the solution down into its simplest

steps• These steps are then translated into computer code• Creating solutions to problems, and then creating simple step-

by-step instructions for a computer based on the solutions is the job of a Computer Programmer

How are Computer Programs Created?

• The solution is translated into computer code using a text editor and a specific Computer Language

• The computer code (known as “Source Code”) is Compiled. This creates a machine language file with instructions the computer can understand (called an “Object File”)

• The Object File is then Linked and an Executable File is created, which can be run by the computer

Computer Languages

• Machine Language (true computer code)

• Symbolic Languages

• High Level Languages

• Natural Languages

Table of Computer Languages

COMPUTER LANGUAGE

WHEN INTRODUCED

EXAMPLES

Machine Language 1940s 0s and 1s only

Symbolic Language Late 1950s Assembly Language

High Level Languages

Mid to Late 1960s BASIC, Fortran, C, Pascal

Natural Languages Soon ?

Example

Print Command for

• Machine Language is 0101010001011010100001

• Symbolic Languages is “PR”

• High Level Languages “PRINT”

• Natural Languages