UNIT-01 INTRODUCTION

WHAT IS SYSTEM SOFTWARE?

There are two main types of software: systems software and application software. Systems software includes the programs that are dedicated to managing the computer itself, such as the operating system, file management utilities, and disk operating system (or DOS).

System software is a software that provides platform to other software. Some examples can be operating systems, antivirus software, disk formatting software, Computer language translators etc. These are commonly prepared by the computer manufacturers. These software consists of programs written in low-level languages, used to interact with the hardware at a very basic level. System software serves as the interface between the hardware and the end users.

The most important features of system software include :
1. Closeness to the system
2. Fast speed
3. Difficult to manipulate
4. Written in low level language
5. Difficult to design

COMPONENT OF SYSTEM SOFTWARE:-

system has three basic types of software: application programs, device drivers, and operating systems.

Application Programs:-

Application programs are the top software layer. You can perform specific tasks with these programs, such as using a word processor for writing, a spreadsheet for accounting, or a computer-aided design program for drawing. The other two layers, device drivers and the operating system, play important support roles. Your system might run one application program at a time, or it might run many simultaneously.

Device Drivers:-

Device drivers are a set of highly specialized programs. Device drivers help application programs and the operating system do their tasks. Device drivers, in particular, adapters, do not interact with you. They interact directly with computer hardware elements and shield the application programs from the hardware specifics of computers.

Operating System:-

An operating system is a collection of programs that controls the running of programs and organizes the resources of a computer system. These resources are the hardware components of the system, such as keyboards, printers, monitors, and disk drives. Your AIX operating system comes with programs, called commands or utilities, that maintain your files, send and receive messages, provide miscellaneous information about your system, and so on.

An application program relies on the operating system to perform many detailed tasks associated with the internal workings of the computer. The operating system also accepts commands directly from you to manage files and security. There are many extensions to the AIX operating system that allow you to customize your environment.

EVOLUTION OF COMPUTER SYSTEM:-

The system software began to be used extensively with the second generation computers in the early 1960's. Before that, the operation of a computer was controlled primarily by human operators. These operators monitored the processing of each job. Typically, when a job ended, a bell rang or light flashed to indicate that another job should be input to computer and started by the operator. In addition, the operator had to activate each peripheral device when that device was needed by the computer. This type of things wasted large amount of computer time and human resources. But with the development of system software or operating systems, a queue of jobs that are a waited can be read onto a disk. The operating system will start each job when system resources are available for its execution. Since due to introduction of system software, human intervention is eliminated, so computers idle time is reduced.

MODEL OF COMPUTER SYSTEM:-

 The IPOS model is one of the simple model that gives us an idea of the complex computer system. The I stands for Input, example of input devices is a keyboard. The keyboard inputs the data in to the computer. Then comes the P, and the P stands for processing, an example of processing device is the processor. Ones the information is entered in the computer by the keyboard, the processor processes the data and this tells what kind of functions the computers should perform. Then the data is stored in the storage/memory devices. An example of a storage device is a hard drive. Once the data is processed it is sent through RAM ( temporary storage device, stores DATA until data is completely stored) and to the hard drive, where the data is permanently stored. Form here the data can be retrieved when you need to. When the data is processed, you can see it, touch it, or hear it  after. This part of the cycle is called after. An example of this is the monitor the monitor displays the processed information on the screen. Some other example of this would be speakers, and the page that comes out of the printer. The IPOS system can also be thought of as the working kitchen system, as mentioned in the diagram. This was just a quick summery of the IPOS model which easily describes the computer system. The truth is that if you go deeper into the subject you will find that the computer system is complex and fascinating system.               

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