File Name: introduction of personal computer and operating systems .zip
This is a list of operating systems.
As the name suggests, an operating system is a type of software without which you cannot operate or run a computer. It acts as an intermediary or translation system between computer hardware and application programs installed on the computer. In other words, you cannot directly use computer programs with computer hardware without having a medium to establish a connection between them.
Besides this, it is also an intermediary between the computer user and the computer hardware as it provides a standard user interface that you see on your computer screen after you switch on your computer. For example, the Windows and the Mac OS are also operating systems that provide a graphical interface with icons and pictures to enable users to access multiple files and applications simultaneously. So, although the operating system is itself a program or software, it allows users to run other programs or applications on the system.
We can say that is works behind the scenes to run your computer. The interaction between a user and the computer does not occur in this system.
The user is required to prepare jobs on punch cards in the form of batches and submit them to the computer operator. The computer operator sorts the jobs or programs and keeps similar programs or jobs in the same batch and run as a group to speed up processing. It is designed to execute one job at a time. Jobs are processed on a first-come, first-serve basis, i. For example, the credit card bill generated by banks is an example of batch processing. A separate bill is not generated for each credit card purchase, rather a single bill that includes all purchases in a month is generated through batch processing.
The bill details are collected and held as a batch, and then it is processed to generate the bill at the end of the billing cycle.
Similarly, in a payroll system, the salaries of employees of the company are calculated and generated through the batch processing system at the end of each month. As the name suggests, it enables multiple users located at different terminals to use a computer system and to share the processor's time simultaneously.
In other words, each task gets time to get executed, and thus all tasks are executed smoothly. Each user gets the processor's time as they get while using a single system.
The duration of time allocated to a task is called quantum or time slice; when this duration is over, OS starts the next task. It uses or runs on multiple independent processors CPUs to serve multiple users and multiple real-time applications. The communication between processors is established through many communication lines such as telephone lines and high-speed buses. The processors may differ from each other in terms of size and function. The availability of powerful microprocessor and advanced communication technology have made it possible to design, develop, and use the distributed operating system.
Besides this, it is an extension of a network operating system that supports a high level of communication and integration of machines on the network. As the name suggests, this OS connects computers and devices to a local area network and manages network resources.
The software in a NOS enables the devices of the network to share resources and communicate with each other. It runs on a server and allows shared access to printers, files, applications, files, and other networking resources and functions over a LAN. Besides this, all users in the network are aware of each other's underlying configuration and individual connections.
It is developed for real-time applications where data should be processed in a fixed, small duration of time. It is used in an environment where multiple processes are supposed to be accepted and processed in a short time. RTOS requires quick input and immediate response, e. Similarly, this system is used to control scientific instruments, missile launch systems, traffic lights control systems, air traffic control systems, etc.
These are used for the applications where timing is critical or response time is a major factor; even a delay of a fraction of the second can result in a disaster.
For example, airbags and automatic parachutes that open instantly in case of an accident. Besides this, these systems lack virtual memory. These are used for application where timing or response time is less critical. Here, the failure to meet the deadline may result in a degraded performance instead of a disaster.
For example, video surveillance cctv , video player, virtual reality, etc. Here, the deadlines are not critical for every task every time.
It was the time before the Second World War when the digital computer was not developed, and there were calculating engines with mechanical relays at this point in time. Later mechanical relays were replaced by vacuum tubes as they were very slow. But, the performance issue was not resolved even with vacuum tubes, besides these machines were too bulky and large as there were made of tens of thousands of vacuum tubes.
Furthermore, each of the machines was designed, programmed, and maintained by a single group of people. The programming languages and operating systems were not known, and absolute machine language was being used for programming. These systems were designed for numerical calculations.
The programmer was required to sign up for a block of time and then insert his plug board into the computer. In the s, punch cards were introduced, which improved the computer performance. It allowed programmers to write programs on punch cards and read them into the system; the rest of the procedure was the same.
This generation started with the introduction of transistors in the mids. The use of transistors made the computers more reliable, and they began to be sold to customers. These machines were called mainframes. Only the big organization and government corporations could afford it. In this machine, the programmer was required to write the program on a paper then punch it on cards.
The card would be taken to the input room and handed over to an operator to get the output. The printer provides the output which was taken to the output room. These steps made it a time-consuming task.
So, the batch system was adopted to address this issue. In a batch system, the tasks were collected in a tray in the form of batches in the input room and read onto a magnetic tape, which was taken to the machine room, where it was mounted on a tape drive. Then using a special program, the operator was to read the first task or job from the tape and run it, and the output was generated onto a second tape. OS automatically read the next job from the tape, and Jobs were completed one by one.
After the completion of the batch, the input and output tapes were taken off, and the next batch was started. The printouts were taken from the output tape. It was mainly used for engineering and scientific calculations. This generation began with the introduction of family of computers of IBM in In this generation, transistors were replaced by silicon chips, and the operating system was developed for multiprogramming, some of them even supported batch processing, time sharing, real-time processing, at the same time.
This generation of OS started with the introduction of personal computers and workstations. Chips that contain thousands of transistors were introduced in this generation that made possible the development of personal computers that supported the growth of networks and thus the development of network operating systems and distributed operating systems. JavaTpoint offers too many high quality services.
Mail us on hr javatpoint. Please mail your requirement at hr javatpoint. Duration: 1 week to 2 week. Internet Intranet Extranet Website. Next Topic Computer Memory. Manual T. Verbal A. Angular 7. Compiler D. Software E. Web Tech. Cyber Sec. Control S. Data Mining. Javatpoint Services JavaTpoint offers too many high quality services.
It checks and decides the allocations and deallocation of memory space to different processes. When a user interacts with a system, the CPU is supposed to read or write operations, in this case, OS decides the amount of memory to be allocated for loading the program instructions and data into RAM. After this program is terminated, the memory area is again free and is ready to be allocated to other programs by the OS. Processor Management : It facilitates processor management, where it decides the order for the processes to access the processor as well as decides the processing time to be allocated for each process.
Besides this, it monitors the status of processes, frees the processor when a process is executed then allocates it to a new process. A driver is a type of translation software that allows the operating system to communicate with devices, and there are different drivers for different devices as each device speaks a different language. Run software applications : It offers the environment to run or use software applications developed to perform specific tasks, for example, Ms Word, Ms Excel, Photoshop, etc.
Data management : It helps in data management by offering and displaying directories for data management. You can view and manipulate files, folders, e. Evaluates the system's health : It gives us an idea about the performance of the hardware of the system. For example, you can see how busy the CPU is, how fast the data is retrieved from the hard disk, etc.
Provides user interface : It acts as an interface between the user and the hardware. It can be a GUI where you can see and click elements on the screen to perform various tasks. It enables you to communicate with the computer even without knowing the computer's language. For example, it receives the input provided by the user through an input device and stores it in the main memory.
Whether it's a desktop or laptop computer, a smartphone or a video game system, every modern computer needs an operating system. That's the core software on the computer that sits between application software and the hardware, distributing memory and computing resources to apps, managing files and enforcing security rules. Operating systems define how a computer stores files, switches between different applications, manages memory, keeps itself secure, and interacts with peripherals like printers and cameras. Different operating systems take different approaches to all of these, which is why you normally can't run a Windows program on a Macintosh computer and why permissions look different on an Android phone than on an iPhone. Some operating systems are designed by groups of people around the world, like the open source, freely available operating system Linux, while others are commercial products made by one company, such as Microsoft's Windows and Apple's macOS.
A personal computer is a general-purpose computer whose size, capabilities and original sale price make it useful for individuals, and is intended to be operated directly by an end-user with no intervening computer operator. This contrasts with the batch processing or time-sharing models that allowed larger, more expensive minicomputer and mainframe systems to be used by many people, usually at the same time. Software applications for most personal computers include, but are not limited to, word processing, spreadsheets, databases, web browsers and e-mail clients, digital media playback, games and myriad personal productivity and special-purpose software applications. Modern personal computers often have connections to the Internet, allowing access to the World Wide Web and a wide range of other resources. Personal computers may be connected to a local area network LAN , either by a cable or a wireless connection.
If you are not required to use this edition for a course, you may want to check it out. The second component of an information system is software. Simply put: Software is the set of instructions that tell the hardware what to do. Software is created through the process of programming we will cover the creation of software in more detail in chapter Without software, the hardware would not be functional. Software can be broadly divided into two categories: operating systems and application software.
What is an operating system? An operating system is a layer of software which takes care of technical aspects of a computer's operation. It shields the user of the machine from the low-level details of the machine's operation and provides frequently needed facilities. There is no universal definition of what an operating system consists of.
As the name suggests, an operating system is a type of software without which you cannot operate or run a computer. It acts as an intermediary or translation system between computer hardware and application programs installed on the computer. In other words, you cannot directly use computer programs with computer hardware without having a medium to establish a connection between them. Besides this, it is also an intermediary between the computer user and the computer hardware as it provides a standard user interface that you see on your computer screen after you switch on your computer.
Anyone can learn for free on OpenLearn, but signing-up will give you access to your personal learning profile and record of achievements that you earn while you study. Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available. A computer requires software just to look after itself and to manage all its components; this is called the operating system.
A personal computer PC is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use. Unlike large, costly minicomputers and mainframes , time-sharing by many people at the same time is not used with personal computers. Institutional or corporate computer owners in the s had to write their own programs to do any useful work with the machines. While personal computer users may develop their own applications, usually these systems run commercial software , free-of-charge software " freeware " , which is most often proprietary, or free and open-source software , which is provided in "ready-to-run", or binary , form. Software for personal computers is typically developed and distributed independently from the hardware or operating system manufacturers. This contrasts with mobile systems, where software is often only available through a manufacturer-supported channel,  and end-user program development may be discouraged by lack of support by the manufacturer.
Search this site. Accounting and Order PDF. Adam and Eve PDF. Aesop for Children PDF. Allure Man PDF.
Иной раз человек в моем положении… - Он замялся, словно принимая трудное решение. - Иногда человек в моем положении вынужден лгать людям, которых любит. Сегодня как раз такой день. - В глазах его читалась печаль.
- Терпи. Потом закрыл глаза и глубоко вздохнул.
Когда улица сделала поворот, Беккер вдруг увидел прямо перед собой собор и вздымающуюся ввысь Гиральду. Звон колоколов оглушал, эхо многократно отражалось от высоких стен, окружающих площадь. Людские потоки из разных улиц сливались в одну черную реку, устремленную к распахнутым дверям Севильского собора. Беккер попробовал выбраться и свернуть на улицу Матеуса-Гаго, но понял, что находится в плену людского потока. Идти приходилось плечо к плечу, носок в пятку.
Чтобы ключ никто не нашел, Танкадо проделал то же самое с Цифровой крепостью. Он спрятал свой ключ, зашифровав его формулой, содержащейся в этом ключе. - А что за файл в ТРАНСТЕКСТЕ? - спросила Сьюзан. - Я, как и все прочие, скачал его с сайта Танкадо в Интернете. АНБ является счастливым обладателем алгоритма Цифровой крепости, просто мы не в состоянии его открыть.
Шифр, подумала .