What is Hard disk and what is its purpose

Hard disk is the secondary storage device, which holds the data in bulk, and it holds the data on the magnetic medium of the disk.

Hard disks have a hard platter that holds the magnetic medium, the magnetic medium can be easily erased and rewritten, and a typical desktop machine will have a hard disk with a capacity of between 10 and 40 gigabytes. Data is stored onto the disk in the form of files. 

Real-Time System

A real time process is a process that must respond to the events within a certain time period. A real time operating system is an operating system that can run real time processes successfully

Difference between Hard and Soft real-time systems: 

                        A hard real-time system guarantees that critical tasks complete on time. This goal requires that all delays in the system be bounded from the retrieval of the stored data to the time that it takes the operating system to finish any request made of it.

                        A soft real time system where a critical real-time task gets priority over other tasks and retains that priority until it completes. As in hard real time systems kernel delays need to be bounded

Important aspect of a real-time system or Mission Critical Systems:

                        A real time operating system has well defined fixed time constraints. Process must be done within the defined constraints or the system will fail. An example is the operating system for a flight control computer or an advanced jet airplane. Often used as a control device in a dedicated application such as controlling scientific experiments, medical imaging systems, industrial control systems, and some display systems. Real-Time systems may be either hard or soft real-time.

Hard real-time:

v  Secondary storage limited or absent, data stored in short term memory, or read-only memory (ROM)

v  Conflicts with time-sharing systems, not supported by general-purpose operating systems.

Soft real-time:

v  Limited utility in industrial control of robotics

Useful in applications (multimedia, virtual reality) requiring advanced operating-system features.

Processor, assembler, compiler, loader, linker and the functions executed by them

Processor:--A processor is the part a computer system that executes instructions .It is also called a CPU

Assembler: -- An assembler is a program that takes basic computer instructions and converts them into a pattern of bits that the computer's processor can use to perform its basic operations. Some people call these instructions assembler language and others use the term assembly language.

Compiler: --- A compiler is a special program that processes statements written in a particular programming language and turns them into machine language or "code" that a computer's processor uses. Typically, a programmer writes language statements in a language such as Pascal or C one line at a time using an editor. The file that is created contains what are called the source statements. The programmer then runs the appropriate language compiler, specifying the name of the file that contains the source statements.

Loader:--In a computer operating system, a loader is a component that locates a given program (which can be an application or, in some cases, part of the operating system itself) in offline storage (such as a hard disk), loads it into main storage (in a personal computer, it's called random access memory), and gives that program control of the compute

Linker: -- Linker performs the linking of libraries with the object code to make the object code into an executable machine code.

Basic functions of an operating system

Operating system controls and coordinates the use of the hardware among the various applications programs for various uses. Operating system acts as resource allocator and manager. Since there are many possibly conflicting requests for resources the operating system must decide which requests are allocated resources to operating the computer system efficiently and fairly. Also operating system is control program which controls the user programs to prevent errors and improper use of the computer. It is especially concerned with the operation and control of I/O devices.

Vodafone Launches New 4G Plan Rs.199 With Unlimited Free Calls & Data | Check Details

This year all telecom operators launched various new plans for its prepaid and postpaid users. After the launch of Jio 4G, the price war between all other telecom operators started and soon each and everyone launched similar plans to compete with Jio. Now Vodafone 4G has launched a new plan for its prepaid customers with free unlimited calls and 1GB Data. The new plan launched by Vodafone is Plan 199. This new plan of Vodafone is similar to Jio monthly plan. Here are the full details of Vodafone latest plan.

Vodafone 4G Latest 199 Plan – Unlimited Calls & 1GB Data

The new plan launched by Vodafone is Vodafone Plan 199. The new latest plan 199 of Vodafone comes with free calls and 1GB data. Vodafone 199 plan comes with free calls which are limited to 250 minutes per day and 1000 minutes per week. Free Calls in Vodafone Latest plan 199 includes all STD and Local Calls. Apart from free calls, the company is also offering 1GB 4G data. The validity of Vodafone latest 199 plan is 28 days. The new pan of Vodafone is launched for the Delhi-NCR.

The new plan of Vodafone 4G comes with certain Terms and Conditions. Users can not make Calls to more than 300 different numbers in a week. If this happens then the company will start charging per call at 30 paise per minute. After the usage of daily free minutes, all the calls will also be charged at 30 paise per minute.

Vodafone 4G 199 Plan Vs Jio 149 Plan

Well, this new plan of Vodafone is a monthly plan and it competes with the monthly plan of Jio. Jio 4G monthly plan is Plan 149. Comparing both the plans, Jio is better than the Vodafone latest 199 plan. Starting with the calls, Vodafone Latest 199 pack comes with free calls with a daily and weekly limit of 250 & 1000 minutes while on the other side the 149 plan of Jio doesn’t come with any limit. Calling in the Jio 149 plan is absolutely free.

Moving to the data usage which is the most important thing, Vodafone 4G latest plan 199 comes with 1GB data usage while the Jio 149 plan comes with 4.2GB high-speed 4G data usage and after the usage high-speed data the speed reduces to 64 kbps, but data remains free. Jio 4G 149 also comes with free SMS.

Source – NDTV

Organs of the human body

              Fig 1: Organs of the human body.