Basic Language System Commands

Continuation from "More on understanding basic language

SOME SYSTEM COMMANDS

 These commands are used without line numbers. They are executed as soon as we press the Enter Key. They are also called direct mode commands.

1. REM: REM is a short form of Remark; It is used to give heading for the program. It is a non-executable command. REM command can be given anywhere in the program.

SYNTAX

LineNo REM Comment

E.g.

10 REM This is a program for print 2 numbers

20 PRINT 5, 6

30 REM Now we can add the numbers

40 PRINT 5 + 6

50 END

RUN

OUTPUT

5      6

11

OK

2. CLS: CLS is a command used for clearing the screen. This command wipes out whatever is displayed on the monitor.

SYNTAX

CLS

E.g.

10 PRINT 4

20 PRINT 8

30 PRINT “JOHN”

40 END

RUN

OUTPUT

4

8

JOHN

OK

CLS

After CLS Command, the screen becomes clear of all data.

3. RUN: RUN Command tells your computer to read the program instructions and execute them. To execute RUN command, press the function key F2.

SYNTAX

RUN

E.g.

10 PRINT “LET”

20 PRINT “US”

30 PRINT “GO”

40 END

RUN

OK

OUTPUT

LET

US

GO

4. LIST: LIST command lists out all the instructions stored in the computer’s memory. It arranges a program in the ascending order and displays all the instructions. To execute RUN command, press the function key F1.

SYNTAX

LIST LineNo

E.g.

10 PRINT “WILLIAM”

20 PRINT “BERNAD”

15 PRINT “SHAKESPEARE”

25 PRINT “SHAW”

LIST

OUTPUT

10 PRINT “WILLIAM”

15 PRINT “SHAKESPEARE”

20 PRINT “BERNAD”

25 PRINT “SHAW”

5. NEW à New command wipes the old program from the computer’s memory. It is food practice to type NEW and press ENTER key before starting a NEW program.

SYNTAX

NEW

6. DELETE: As the name indicates, this command is used to remove any unwanted line from your program.

SYNTAX

DELETE

E.g.

10 PRINT 5

20 PRINT 3

30 PRINT 10

40 END

         

One line can be removed by typing DELETE 20.

Line no 20 will be removed from the memory.

Now LIST command should be used to view the program

10 PRINT 5

30 PRINT 10

40 END

POINTS TO REMEMBER

1. REM or REMARK statement is used as the heading of the title of the program

2. CLS command is used to clear the screen.

3. NEW command clears the program form the memory of the computer.

4. DELETE command is used to remove any line from the program.

5. RUN command executes the program.

Components of a Computer

The internal architechtural design of computers may differ from one another. But there is a basic organization seen in all computers
The block diagram of basic computer organization is shown below:

The diagram shows that a computer consists of the Central Processing Unit (CPU), memory and input / output unit.

Computer Overviiew

Introduction

The word 'compute' comes from the word 'compute' which means to calculate. So, a computer is normally considered to be calculating device that can speedily perform arithmetic and logical operations.

the original objective for inventing a computer was to create a fast calculating machine, through a major part of work done by computers nowafays is non-mathematical. Therefore, defining a computer assembly only as a calculatinng device is not justified.

The computer is an electronic device designed to accept and store input data, manipulate it and output results under the direction of detailed, step-by-step stored programs and instructions.

Data

It denotes raw facts and figures such as numbers, words, amount, quantity, that can be processed, manipulated or produced by the computer. for example: Rita, 18, XI B. This is raw data.

Information

It is a meaningful and arranged form of data. Raw data does not make any sense on its own. So, it has to be arranged in a meaningful manner such that it makes sense. For example, Information that makes sense can be Rita aged 18 is in class XI B.

Hardware andSoftware

A computer consists of two fundamental components. One is called hardware, the other sothe software. Hardware refers to the physical components or blocks, for example, CPU, memory, input and output devices. Software is the package of instructions designed to operate the conserened hardware, for example, MS-DOS, Microsoft Office, etc. In fact, we can divide software into two broad categories:

1) System Software: It runs the basic functioning of a computer system. It consists of operating systems, compilers, translators, etc.

2) Application Software: the basic aim of making and running a computer is to get work done from it. So, programs which are developed in order to serve a particular application are known as application software. For example, Microsoft Office, Tally, etc.