Computers: Hardware, and Software Software: Set of Programs made of Instructions An instruction is a simple elementary Task to be performed by the computer Example of instructions: Read an input from the keyboard. Display something o
Input and Output
Read, and Readln
The following statement: Writeln(123) will give as output the following:
123 The number is printed using 3 spaces
Write, and Writeln
Unless specified Pascal uses fixed width output
Repetition Statements Loops
In the programs studied so far a statement is executed only once. Sometimes a process can be repeated many times: repetition The repetition of steps in a program is called Loop Pascal has three loop control statements: While F
The Boolean Data Type
This data type allows us to represent something as either True or False. Syntax:
Const flag = True; Var Variable_Name : Boolean
Var Flag: Boolean Flag := True Writeln(Flag) (* will give as output True *)
Describe the basic components of a network Explain the methods of data transmission Differentiate among the various kinds of communications channels Describe the different types of computer networks Describe different Internet applications
Chap_2 => Main Memory => Stores information (to be used by the CPU) temporarily. A need for a permanent storage => Secondary Storage Mainly:
Hard Disk Floppy Disk External Storage (Tapes, Cartridges, )
Why organize Data?
To easily f
Introduction Whats a Computer?
An electronic device:
Gets Input Processes the Input Output
Why Use a Computer?
Time Accuracy Reliability
You type an MS_Word document (Input) You click on the Print button (Process) The document is printe
The Processing Unit
33 Megahertz, 486 machines 8 Megabytes of RAM Coprocessor Cache memory . Some Computer characteristics Some Purchase a computer Purchase Overview of these characteristics CPU, how data circulates inside?, .