Techy Drift

 An operating system is a program that manages the computer hardware.      It also provides a basis for application programs and acts as a intermediary between computer user and computer hardware. The operating system is large and complex. It is divided into separate subsystems, each with carefully defined functions, input, output and function. This arrangement and relationship between subsystems or components of a complex system is called operating system structure. Simple Structure      Some systems do not have a well defined structure. such system does not break the system into subsystems, and has no distinction between user and kernel modes. this system allows all programs direct access to the underlying hardware.     MS DOS  is the best example of such a system. A few people  was originally designed and implemented it. And gradually DOS became popular and important.     This simple layered approach is used b...

 Based on number of general purpose processors computer systems are classified into three types.They are: Single Processor Systems. Multiprocessor Systems. Clustered Systems. Single Processor Systems From the name it is very clear that it has only single processor. A major central processing unit that can execute a set of general utility instructions, including user process instructions. There are some other special purpose processors present that performs device specific task. In the single processor system apart from the main central processing unit(CPU) there are also other processors which are present which does not do the general purpose task but it performs some device specific task. It means that we have a certain devices in our computers like keyboard, disk, etc. for all this they may be some microprocessor  which is specified to do a specific task related to that device like for example keyboard, when we press a key on our keyboard the keystroke has to be converted to...

 Types of Operating System Batch Operating system Time sharing Operating system Distributed Operating system Network Operating system Real Time Operating system Multi programming/Processing/Tasking Operating system Mobile Operating System Batch Operating System               In a Batch operating system the similar jobs are grouped together into batches with the help of some operators and these batches are executed one by one. For example, suppose we have ten programs, some are written in c++ programming language, Some are written in c programming language and the rest are written java programming language. Now, every time we run these programs one by one, we have to load the compiler of that particular language and then run the code. But if we do a batch of these ten programs, The advantage with this approach is that for the c++ batch, you only need to load the compiler once. Similarly, for Java and C , the compiler only needs to load once an...

 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 software that performs all the basic functions of file management, storage management, process management, managing input and output, and controlling peripherals such as disk, drivers and printers. Functions of Operating System Device Management  File Management Memory Management Process Management Mastermind Storage Management Handling input/output operations Security Functions of Operating System Device Management          Operating system manages device communication via their respective drivers. It does the following activities for device management: Keeps tracks of all devices, input/output controller is responsible for this task. Decides which process gets the device when and for how much time Allocates the device in an efficient way. De-allocates dev...

 The hardware and software used to deliver applications to the user can be seen in a layered or hierarchical manner as shown in the following figure. Layers and Views of a Computer System The user of those applications, the end user, generally is not concerned with the details of computer hardware. Therefore, the end user sees the computer system in terms of a set of applications. An application can be expressed in the programming language and developed by the application programmer.If one develops an application program as a set of machine instructions that is fully responsible for controlling the computer hardware, one is faced with a very complex task.To ease this chore, a set of system programs is provided. Some of these programs are referred to as utilities. These implement frequently used functions that assist in creation of program, files management, and the control of I/O devices. A programmer will make use of these facilities in developing an application, and the appl...

 The processor contains a set of registers that provide faster and smaller memory than the main memory. It provides two functions User-visible registers: Enable the machine or assembly language programmer to minimize main memory references by optimizing register use. For high-level languages, an optimizing compiler will attempt to make intelligent choices of which variables to assign to registers and which to main memory locations. Some high-level languages, such as C,allow the programmer to suggest to the compiler which variables should be held in registers. Control and status registers: It is used by the processor to control the operation of the processor and by privileged OS routines to control the execution of the program.      There is no clean division of registers in these two categories. For example, on some processors, the program counter is visible to the user, but for the most part it is not. For the purpose of the following discussion, however, it is conv...

Basic Elements  At a top level, a computer consists of Memory, Processor and I/O components, with one or more modules of each type. These components are interconnected in some fashion to achieve the main function of the computer which is to execute the programs. Thus, there are four main structural elements: Processor: Actually the main job of the processor is to control the operation of the computer and performs its data processing functions. When there is only one processor, it is often referred to as the Central Processing Unit (CPU). I/O Modules: These are used to move data between the computer and its external environment. The external environment consists of variety of devices, including secondary memory for example disks,communications equipment, and terminals. Main Memory: It stores data and programs. This memory is usually volatile; i.e. the contents of the memory are lost when the computer is shut down. In contrast, the contents of disk memory are retained even when the c...

 Operating System:- An operating system is a program that manages the computer hardware.      It also provides a basis for application programs and acts as a intermediary between computer user and computer hardware. Some Operating Systems Windows Linux Ubuntu Mac OS X  IOS Android CLICK 👇 TO GET MORE   Types of Operating System Batch Operating system Time sharing Operating system Distributed Operating system Network Operating system Real Time Operating system Multi programming/Processing/Tasking Operating system Mobile Operating System CLICK 👇 TO GET MORE Functions of OS     Device Management  Process Management  Memory Management Security File Management  Mastermind Storage Management Input and Output Operations Main goals of Operating System Convenience-Provides convenient to user Efficiency-Operating system allows the computer system resources to be used in an efficient manner Ability to evolve:- An operating system should be c...