computer basic ppt

8/8/2019 Computer Basic Ppt

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PRESENTED BY: Ajay Bharti

Parul Saini

Praveen Arun Pandey

Chetan Rathod



Definition of computer:

y The word computer comes from the word compute

INPUTUNIT MEMORY

CU

ALU

OUTPUT



CHARACTERISTICS:y Automatic

y Speed

y Accuracy y Diligence

y Versatility

y Power of Remembering

y No I.Q.

y No feeling

y Dependent



COMPUTER GENERATIONS:y FIRST GENERATION (1942-1955)

y SECOND GENERATION (1955-1964)

y THIRD GENRATION (1964-1975)y FOURTH GENERATION (1975-1989)

y FIFTH GENERATION (1989- present)



OPERATING SYSTEMy Operating system is a system software, consisting of

program and data that runs on computer and manage

the computer hardware. It is an integrated set of programs that controls the resources of a computersystem and provides its users with an interface that iseasier to use than the bare machine



FUNCTIONS OF AN OS

y PROCESS MANAGEMENT: It take care of creation

and deletion of processes.y MEMORY MANAGEMENT: It take care of allocation

and de-allocation of memory space to programs inneed of this resource.

y FILE MANAGEMENT: It takes care of file-relatedactivities.

y SECURITY : It protects the information of a computersystem against unauthorized access.



TYPES OF AN OS

y MULTIPROGRAMMING

y MULTIPROCESSING

y MULTITASKINGy BATCH PROCESSING



MULTIPROGRAMMING

y Only one job is processed at a time and all systemresources are available exclusively for the job until its

completion

Storage device

Job A

Job B

Job C Waiting..

CPU



MULTIPROCESSING

y Multiprocessing is the simultaneous execution of twoor more processes by a computer system having more

than one CPU.



MULTITASKING

y Technically it is same as multiprogramming . Butmultiprogramming for multi-user systems (systems

that are uses simultaneously by many users such asmainframe system) and multitasking for single-usersystems (systems that are used by only one user at atime).



BATCH PROCESSING

y A batch processing system is a one where programesdata are collected together in a batch before processing

start.



COMPUTER LANGUAGESprogrammer uses a computer languages to instruct a

computer what he wants it to do.



TYPES OF CL:

y It can be classified into following categories:

1. low level language &

2. High level language.



LOW LEVEL LANGUAGE1. MACHINE LEVEL LANGUAGE

2. ASSEMBLY LANGUAGE.



MACHINE LEVEL LANGUAGE

y The machine language of a computer is writtennormally as strings of binary 1s & 0s. The circuitry of a

computer is wired in a manner that is recognizes themachine languages instructions immediately, andconverts them into electrical signals needed to executethem.

y Instruction format

opcode operand



LIMITATIONS OF MLL:

y 1.MACHINE DEPENDENT.

y 2.DIFFICULT TO PROGRAM.

y 3. DIFFICULT TO MODIF Y.



ASSEMBLY LANGUAGEy IT introduced in 1952 helped in overcoming the

limitation of machine language programming.

y In this programming language programmer not keeptrack of storage locations of the data and instructions

while writing an assembly language program. In it noneed to tell the computer where to place each dataitem or instruction of a program.

y An assembly language program must be converted into

its equivalent machine language program before it canbe executed on the computer.

ALP ASSEMBLER MLP



PROGRAMME IN A.L.L.START PROGRAM AT 0000

START DATA AT 1000

SET ASIDE AN ADDRESS FOR FRSTSET ASIDE AN ADDRESS FOR SCND

SET ASIDE AN ADDRESS FOR ANSR

CLA FRST

ADD SCND

STA ANSR

HLT



ADVANTAGES& LIMITATIONS:

y EAISER TO UNDERSTAND AND USE

y EAISER TO CORRECT ERRORS

y EAISER TO MODIF Y y NO WORRY ABOUT ADDRESSES

y MACHINE DEPENDENT

y KNOWEDGE OF H/W REQUIRED



HIGH LEVEL LANGUAGEy High level language were designed to overcome

limitations of LLL.

y FEATURES:

Machine independent

No worry about h/w structure

Simple in programming.

Easy to understand



COMPILER

y A computer can execute only machine language prog.So, HLL prog must be converted into its equivalent

machine language prog before it can be executed on acomputer.

y TRANSLATION PROCESS OF A COMPILER

HLL COMPILER MLL



INTERPRETER

y It is another type of translator used to translate a HLLprogram into its equivalent machine language

program.

y

ROLE OF

AN INTERPRETER

HLL INTERPRETER MLL



THANK YOU

computer basic ppt

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