Dutsi Communication

  Due to public demand, here are 49 computer shortcuts that are useful for everyday use: 1. Ctrl + C for copying 2. Ctrl + V for pasting 3. Ctrl + Z for undoing 4. Ctrl + Y for redoing 5. Ctrl + A for selecting all 6. Ctrl + X for cutting 7. Ctrl + S for saving 8. Ctrl + F for finding 9. Ctrl + P for printing 10. Ctrl + N for creating a new document 11. Ctrl + B for bolding text 12. Ctrl + I for italicizing text 13. Ctrl + U for underlining text 14. Ctrl + Shift + N for creating a new folder 15. Ctrl + Shift + Esc for opening Task Manager 16. Ctrl + Alt + Del for opening the security options screen 17. Windows key + D for minimizing all windows 18. Windows key + E for opening File Explorer 19. Windows key + L for locking the computer 20. Windows key + R for opening the Run dialog box (Run Command) 21. Windows key + S for opening the search bar 22. Alt + Tab for switching between open windows 23. Alt + F4 for closing the current window 24. F2 for renaming a file or folder 25. F5 for...

  Input/Output OS Software Basically, input/output software organized in the following four layers: Interrupt handlers Device drivers Device-independent input/output software User-space input/output software In every input/output software, each of the above given four layer has a well-defined function to perform and a well-defined interface to the adjacent layers. Now let's describe briefly, all the four input/output software layers that are listed above. Interrupt Handlers Whenever the interrupt occurs, then the interrupt procedure does whatever it has to in order to handle the interrupt. Device Drivers Basically, device drivers is a device-specific code just for controlling the input/output device that are attached to the computer system. Device-Independent Input/Output Software In some of the input/output software is device specific, and other parts of that input/output software are device-independent. The exact boundary between the device-independent software and drivers is dev...

  Operating system security Operating system security (OS security) is the process of ensuring OS integrity, confidentiality and availability. OS security refers to specified steps or measures used to protect the OS from threats, viruses, worms, malware or remote hacker intrusions. OS security encompasses all preventive-control techniques, which safeguard any computer assets capable of being stolen, edited or deleted if OS security is compromised. OS security may be approached in many ways, including adherence to the following: Performing regular OS patch updates Installing updated antivirus engines and software Scrutinizing all incoming and outgoing network traffic through a firewall Creating secure accounts with required privileges only (i.e., user management)  We're going to discuss following topics in this chapter. Authentication One Time passwords Program Threats System Threats Computer Security Classifications Authentication Authentication refers to identifying each user...

  Threads Thread is an execution unit which consists of its own program counter, a stack, and a set of registers. Threads are also known as Lightweight processes. Threads are popular way to improve application through parallelism. The CPU switches rapidly back and forth among the threads giving illusion that the threads are running in parallel. As each thread has its own independent resource for process execution, multpile processes can be executed parallely by increasing number of threads. Types of Thread There are two types of threads: User Threads Kernel Threads User threads, are above the kernel and without kernel support. These are the threads that application programmers use in their programs. Kernel threads are supported within the kernel of the OS itself. All modern OSs support kernel level threads, allowing the kernel to perform multiple simultaneous tasks and/or to service multiple kernel system calls simultaneously. Multithreading Models The user threads must be mapped t...

 Operating System - I/O Hardware Overview Computers operate on many kinds of devices. General types include storage devices (disks, tapes),transmission devices (network cards, modems), and human-interface devices (screen, keyboard, mouse). Other devices are more specialized. A device communicates with a computer system by sending signals over a cable or even through the air. The device communicates with the machine via a connection point termed a port (for example, a serial port). If one or more devices use a common set of wires, the connection is called a bus.In other terms, a bus is a set of wires and a rigidly defined protocol that specifies a set of messages that can be sent on the wires. Daisy chain When device A has a cable that plugs into device B, and device B has a cable that plugs into device C, and device C plugs into a port on the computer, this arrangement is called a daisy chain. It usually operates as a bus. Controller A controller is a collection of electronics that...

 Services of Operating System An operating system is an interface which provides services to both the user and to the programs. It provides an environment for the program to execute. It also provides users with the services of how to execute programs in a convenient manner. The operating system provides some services to program and also to the users of those programs. The specific services provided by the OS are off course different. Following are the common services provided by an operating system: Program execution I/O operations File system manipulation Communication Error detection Resource allocation Protection 1) Program Execution An operating system must be able to load many kinds of activities into the memory and to run it. The program must be able to end its execution, either normally or abnormally. A process includes the complete execution of the written program or code. There are some of the activities which are performed by the operating system: The operating system Loa...

  What is a Process? Process is the execution of a program that performs the actions specified in that program. It can be defined as an execution unit where a program runs. The OS helps you to create, schedule, and terminates the processes which is used by CPU. A process created by the main process is called a child process. Process operations can be easily controlled with the help of PCB(Process Control Block). You can consider it as the brain of the process, which contains all the crucial information related to processing like process id, priority, state, CPU registers, etc. What is Process Management? Process management involves various tasks like creation, scheduling, termination of processes, and a dead lock. Process is a program that is under execution, which is an important part of modern-day operating systems. The OS must allocate resources that enable processes to share and exchange information. It also protects the resources of each process from other methods and allows s...

  Operating System Types Single-user systems A computer system that allows only one user to use the computer at a given time is known as a single-user system. The goals of such systems are maximizing user convenience and responsiveness, instead of maximizing the utilization of the CPU and peripheral devices. Single-user systems use I/O devices such as keyboards, mice, display screens, scanners, and small printers. They can adopt technology developed for larger operating systems. They may run different types of operating systems, including DOS, Windows, and MacOS. Linux and UNIX operating systems can also be run in single-user mode. Batch Systems Early computers were large machines run from a console with card readers and tape drives as input devices and line printers, tape drives, and card punches as output devices. The user did not interact directly with the system; instead, the user prepared a job, (which consisted of the program, data, and some control information about the natu...

  Operating System (OS) Overview Operating System is an interface between the user and the hardware and enables the interaction of a computer’s hardware and software. Also, an operating system is a software which performs all the basic tasks like file management, memory management, storage management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers. Types of Operating System (OS)  All different operating system types are listed below – Windows iOS MAC OS Ubuntu Novell Netware Unix Linux Mobile Operating System These are some of Mobile Operating System – iOS Symbian Blackberry Windows Android OS Bada Operating System Functions  All  Operating system functions are shared below – 1. DEVICE MANAGEMENT – Operating System manages device communication via their respective drivers. It does the following activities for device management − Keeps tracks of all devices. I/O controller is responsible for this task...

  Software Development Life Cycle The Software Development Life Cycle (SDLC) refers to a methodology with clearly defined processes for creating high-quality software. in detail, the SDLC methodology focuses on the following phases of software development: Requirement analysis Planning Software design such as architectural design Software development Testing Deployment This article will explain how SDLC works, dive deeper in each of the phases, and provide you with examples to get a better understanding of each phase. What is the software development life cycle? SDLC or the Software Development Life Cycle is a process that produces software with the highest quality and lowest cost in the shortest time possible. SDLC provides a well-structured flow of phases that help an organization to quickly produce high-quality software which is well-tested and ready for production use. The SDLC involves six phases as explained in the introduction. Popular SDLC models include the waterfall model...

Computer Careers It’s safe to say that now is a great time to pursue a career in technology. In fact, the Bureau of Labor Statistics (BLS) projects employment of professionals in computer and information technology careers to increase much faster than average.Let us introduce you to some of the many computer jobs worth considering. 1. Big data engineer Big Data Engineers spend their work days communicating with business users and data scientists with the goal of translating business objectives into workable data-processing workflows. These positions require a robust knowledge of statistics, experience with programming and the ability to design and implement working solutions for common big data challenges. 2. Applications architect Digital pros who land a position like applications architect are required to maintain a high level of technical expertise while also excelling in areas like planning, coordination, communication and teamwork. These professionals are tasked with designing maj...

Common Computer, IT, and Technology Abbreviations There are literally thousands of computer abbreviations out there. Many are concerned with the technical aspects of the computer, while others deal with personal communication. Following are some more common ones that you may have heard but do not know exactly what they mean. Common Computer Abbreviations Operating Systems and Data Storage Two of the most basic components of any computer system are its operating system and data storage. Many acronyms reflect these basic requirements. AFA - This acronym stands for All Flash Array, a grouping of flash memory devices that helps boost performance. BIOS - This is the Basic Input Output System, which controls the computer, telling it what operations to perform. These instructions are on a chip that connects to the motherboard. BYTE - A byte is a storage unit for data. KB is a kilobyte (1024 bytes); MB is a megabyte (1 million bytes); and GB is a gigabyte (1000 megabytes). CPU - This stands fo...