SYSTEM SOFTWARE

 INTRODUCTION A computer system consist of three basic elements; hardware, software and human ware. A computer needs both hardware and software for its proper functioning. By software we mean computer instructions or data. Anything that can be stored electrically is software. The storage devices and display devices are hardware. Software refers to a computer program, procedure, rules and associated documentation and data pertaining to the operation of a computer system. There are mainly two type of software; application software and system software. System software is computer software designed to operate the computer hardware and to provide and maintain a platform for running application software. System software is generally applied by the hardware manufacture. System software consist of low level programs that interact with the computer at a very basic level. This includes operating system, compiler and utilities for managing computer resources. TYPES OF SYSTEM SOFTWARE OPERATING SYSTEM UTILITY SOFTWARE TRANSLATORS (a)Assemblers (b)Compilers (c) Interpreters 4. BIOS (BASIC INPUT / OUTPUT SYSTEM) 5. FIRM WARE OPERATING SYSTEM (OS) An operating system were originally developed to handle one of the most complex input or output operations; communicating with a variety of disk drives. An OS is an interface between hardware and user which is responsible for management and coordination of activity and sharing of resources of a computer that act as a host for computing application run on a machine. OS contain the information that tells the computer how to handle its basic function such as receiving information, display information, storing and retrieving information and printing or telecommunicating information. As a host one of the purposes of an OS is to handle the resource allocation and access protection of the hardware. This relieves application programmers from having to manage these details. OS offers a number of services to application programs and user. Applications access these services through Application Programming Interface (APIs) or system calls. For hand and desk top computer, the user interface generally implemented as an application program that run outside the OS. OS acts as a master control program on a computer. It controls flow of signal from CPU. User Application Operating system Hardware UTILITY SOFTWARE Utility software is a kind of system software designed to help analyze, configure, optimize and maintain the computer. A single piece of utility software is usually called utility or tool. Utility software should be contrasted with application software, which allows users to do things like creating text documents, playing games, listening to music or surfing the web. Rather than providing these kind of user- oriented or output – oriented, functionality, utility software usually focuses on how the computer infra structure (including the computer hardware, OS, application software and data storage). Most utilities are highly specialized and designed to perform only a single task or also some utility suites that combine several features in one software. Most major OS come with several pre- installed utilities. TRANSLATORS A translator is a program which converts statements written in one language into statements in another language. Two types of translators have already been introduced but there are three basic types of translators. · Assemblers · Compilers · Interpreters Assemblers It is a computer program, which translates symbolic code, and symbolic addressed into actual machine addresses. Assembler do following:- - Includes the necessary linkage for closed sub- routines. - Allocates areas of main storage. - Indicate invalid source language instructions. - Produces the object program on disk or tape. - Produces a printed listing of the object program together with commends. Notice that one symbolic instruction is translated into one machine instruction which is one feature that distinguishes a low level language from high level language. Compiler A compiler is a computer program (or set of programs) that transforms source code written in a computer language( the source of language) in to another computer language or the compiler translates whole of the high-level language source program into machine code object program prior to the object program being loaded into main memory and executed. The most common reason for the wanting to transform source code is to create an executable program. The name ‘compiler’ is primarily use for programs that translate source code from high-level programming language to a lower level language. A program that translates from a low level language to a higher level one is a ‘decompile’. A program that translates between high-level languages is usually called language translator or source-to-source compiler or source to source translator. A compiler is likely to perform many or all of the following operations: lexical analysis, preprocessing, parsing, semantic analysis, code generation and code optimization. If a compiler is used, the same program need only be translated once. Thereafter, the object program can be loaded directly in to main storage and executed. The compilers do the following program, (a) Translates the source program statement in to machine code. (b) Includes linkage for closed sub -routines. (c) Allocates areas of main storage (d) Produces a printed copy of the source and object program. (e) Produces the object programs on disk or magnetic tape. (f) Produces a list of errors found during compilation. E.g. the use of ‘works’ or statement not included in language vocabulary; or violation of rule of syntax. Interpreters An interpreter is used, the same program will be translated every time the program is executed. Execution carried out in this way may be ten times slower than the execution of the equivalent object programs. BIOS (Basic Input/ Output system) It is also known as system BIOS. It is the interface between hardware and operating system. The BIOS is a boot firmware, designed to be the first code run by a PC when powered on. The initial function of BIOS is to identify, test and initialize system devices such as the video display card, hard disk, floppy disk, and other hardware. The BIOS sets the machine hardware in to known state, so that the software stored on compactable media can be loaded, executed and given control of the PC. This process is known as booting or booting up, which is short for boot strapping. BIOS programs are stored on a chip and are built with various devices that make up the complimentary chipset of the system. This provides a small library of the basic input or output function that can be called to operate and controlled peripherals such as the key board, text display function and so on. In the IBM PC and AT, certain peripheral card such as hard – drive controller and video display adaptors carried their own BIOS extension ROM, which provide additional functionality. Utility software and executive software functionality will provide replacement software inter-faces to application. FIRMWARE In electronics and computing, firmware is a term often used to denote the fixed, usully rather small, programmes and data structure that internally control various electronic devices. Typical examples of devices containing firmware range from end-user products such as remote controls or calculators, through computer parts and devices like hard disks, key board TFT screens or memory cards, all the way to scientific instrumentation and industrial robotics. Also more complex consumer devices, such as mobile phone, digital cameras etc. contain firmware to enable to devices basic operation as well as complimenting higher level functions. There is no strict or well defined boundaries separate firmware from software. CONCLUSION The human expects from computer not only to solve our problem but also to provide a more user friendly environment to work with computer. The software developed to provide such an environment that is system software. System software includes any program that is designed to improve the use or the performance of a computing system.