COMPUTER SYSTEM (CLASS -XI) (PART - 4)

 COMPUTER SYSTEM  

(PART -IV)

CLASS - XI

Storage Unit

Computer need to store and retrieve data for processing. Since primary memory has a limited storage capacity and is not permanent, secondary storage devices are used to store large amount of data permanently. There are various types of secondary devices available these days.

Hard Disks: A hard disk is a set of stacked disks. Each disk has data recorded electromagnetically in concentric circles, or tracks, on the disk. The hard disks of today have storage capacity measured in giga bytes upto tera bytes.

CD/DVD: The compact disk or CDs are optical media. The CDs are relatively cheap and have a storage capacity upto 700 mb. DVD can hold upto 17 GB of data

Flash Memory: A flash device is a small, ultra-portable storage device. It has no moving parts unlike magnetic storage device.

Blue Ray Disk: It is an optical disc storage media format. Its main uses are high-definition video and data storage.

Types of Software

The software can be classified into two categories:

     System Software

     Application Software

System Software: The software that controls internal computer operations is called system software.

The system software can further be classified into two categories.

     Operating System

     Language Processor

Operating System: The primary goal of an operating system is thus to make the computer system convenient to use and secondary goal is use to computer hardware in an efficient manner. An operating system is an important component of a computer system which controls all other components of the computer system.

Language Processor: A language processor is a special type of computer software that can translate the source code into an object code or machine code.

There are 3 types of language processors:

Assembler: This language processor converts the program written in assembly language into machine language.

Interpreter: An interpreter is a type of system software that translates and executes instructions written in computer program line-by-line, unit-by-unit etc.

Compiler: A Compiler is another type of system software that translates and executes instructions written in a computer program in one go.

Application Software: An Application Software is a set of programs necessary to carry out operations for a specified application.

Application software can further be subdivided into four categories:

        Package               Utilities                 Customized Software                    Developer Tools

Package: Some most common categories of general application software are:

•  Word processing software

• Spreadsheet

• Database Management System

• Desktop Publishing Software

• Graphics, multimedia, and presentation applications.

Utilities: Utilities are those application programs that assists the computer by performing housekeeping functions like backing up disk or scanning/cleaning viruses or arranging information etc.

Business Software: This type of software is specifically created software according to business requirements. This type of software is developed to meet the general requirements of a business. A company wants to computerize its ‘Accounts’ department and get a software that can serve its needs. Such a software is business software.

Examples : Inventory Management /system, Payroll system, Financial Accounting, Hotel Management software etc.

Software Libraries: A software library is a predefined and available to use, suite of data and programming code in the form of prewritten code/functions/scripts/classes etc. that can be used in the development of new software programs and applications.

For Example, Python comes equipped with many software libraries. Some of these are:

NumPy (Numerical Python):It provides an abundance of useful features and functions for operations on numeric arrays and matrices in Python.

SciPy (Scientific Python): SciPy contains modules for liner algebra, optimization, integration, and statistics.

Pandas Library: Pandas is a python package designed to do work with “labeled” and “relational” data. It is designed for quick and easy data manipulation, aggregation, and visualization.

DEVELOPMENT OF COMPUTER/CALCULATOR TO SMART DEVICE

Abacus is known to be the first mechanical calculating device. Which was used to be performed addition and subtraction easily and speedily? This device was a first develop Ed by the Egyptians in the 10th centaury B.C, but it was given it final shape in the 12th centaury A.D. by the Chinese educationists.

NAPIER’S BONES John Napier’s of Scotland invented a calculating device, in the year 1617 called the Napier Bones. In the device, Napier’s used the bone rods of the counting purpose where some no. is printed on these rods. These rods that one can do addition, subtraction, multiplication and division easily.

Pascal's calculator In the year 1642, Blaise Pascal a French scientist invented an adding machine called Pascal’s calculator, which represents the position of digit with the help of gears in it.

Leibnz Calculator In the year 1671, a German mathematics, Gottfried Leibniz modified the Pascal calculator and he developed a machine which could perform various calculation based on multiplication and division as well.

Analytical EngineIn the year 1833, a scientist form England knows to be Charles Babbage invented such a machine. Which could keep our data safely? This device was the first mechanical computer. Charles Babbage is also known as the father of the computer.

1943-1944: Two University of Pennsylvania professors, John Mauchly and J. Presper Eckert, build the Electronic Numerical Integrator and Calculator (ENIAC). Considered the grandfather of digital computers

1976: Steve Jobs and Steve Wozniak start Apple Computers on April Fool's Day and roll out the  Apple i, the first computer with a single-circuit board, according to Stanford University.

2007: The iPhone brings many computer functions to the smartphone.

GENERATION OF COMPUTER

Generation	Year	Characteristics
1st	1944 – 59	Use Valves (Vacuum tubes)
2nd	1959 – 64	Use transistors
3rd	1964 –75	Large Scale Integrated Circuits
4th	1975 -	Very Large-Scale Integrated Circuits
5th	Under development	Artificial Intelligence based computers

Trouble shooting with parts of computer

• First check the cable. Unplug it from the computer and the outlet. Replug in both sides and try booting it again.

• Check the wall outlet. Plug something else into the outlet and see if it works. If have a surge protector try a different outlet.

• Turn the system off and wait 30 seconds and then try again.

• Reach behind the machine and see if feel air blowing out of the power supply. If do, then you know the machine is getting some power.

• Look at the keyboard for the indicator lights being lit up as the machine boots.

• Sometimes the monitor has something to do with the system acting up. Unplug the power cord from the monitor and the wall and re-plug it. Unplug the cable from the computer to the monitor and re-plug it into the monitor. Try rebooting.