4th Class Computers Science Software Classification System Software

           System Software System software refers to the programs that controls internal computer operations and make the best use of the hardware. The software that controls internal computer operations (reading data from input devices, transmitting processed information to the output devices, checking system components, converting data/instructions to computer understandable form) is known as system software. System software offers a protective shield to all software applications. It also provides support to the physical components of computers. System software coordinates all external devices of computer system like printer, keyboard, displays, etc. It can be further classified as - operating system, language processors, device drivers and utilities.                     Operating System The operating system is just like a secretary who does all the work for the boss. The primary goal of an operating system is to make the computer system convenient to use and the secondary goal is to use the computer hardware in an efficient manner. A boss may ask his secretary to fix an appointment with another person, reserve a seat in the seminar, find out the status of a project, etc.                  Similarly when you ask the operating system to do things such as: v  Copy A dat. v  Delete myfile.dat v  Type readme.doc You assume that the operating system knows how to perform copy or delete or type. The user does not have to know how the operating system does this. An operating system is a master control program which controls all other components of it. The major components are the hardware, the OS, the human ware (users) and the application program routines like compiler, linkers, database management systems and utility programs. Where hardware provides the basic computing resources, the application program routines define the ways in which these resources are used to solve the computing problems of the users. The OS controls and coordinates the use of the hardware among the various application programs for the various users. (See Figure 4.4.2)                                           Language Processor Programmers prefer to write their programs in one of the HLL (High Level Programming Languages) because it is much easier to code in such languages. However, the computer does not understand any language other than its own machine language (binary code), therefore, it becomes necessary to process a HLL program so as to make it understandable to the computer. The system programs which perform this very job are language processors. (See Figure 4.4.3)                                    The 3 different types of language processors are the following: 1.       Assembler: This language processor converts the program written in assembly language into machine language. 2.       Interpreter: This language processor converts an HLL program into machine language by converting and executing it line by line. If there is any error in any line, it reports it at the same time and program execution cannot resume until the error is rectified. Interpreter must always be present in the memory every time the program is executed as every time the program is run, it is first interpreted and then executed. For error debugging, the interpreter is very useful as it reports the errors at the same time. But once errors are removed, unnecessary usage of memory takes place as it has to be present in the memory always. 3.       Compiler: It also converts the HLL program to machine language but the conversion manner is different. It converts the entire HLL program in one go, and reports all the errors of the program along with the line numbers. After all the errors are removed, the program is recompiled.                  Utility Programs These are programs designed to perform useful tasks that most users would wish to perform from time to time, such as file searching, sorting of data, backing up data, etc. Utilities are often provided with the OS but many are provided by third- party software houses.       Joish and Ronald are discussing about system software of a computer. Identify the correct one. Joish: The software that controls internal computer operations is known as system software and its coordinates all external devices of computer system like printer, keyboard, display device, etc. Ronald: System software does not offer a protective shield to all software applications. (A) Joish is correct                                                           (B) Ronald is correct (C) Both are partially correct                                       (D) Both are correct (E) Both are incorrect   Answer: (A) Correct Option: (A) Information given by Joish is correct. Incorrect Options: (B) Information given by Ronald is incorrect. Therefore, option (B) is incorrect. (C) Joish is fully correct whereas Ronald is fully incorrect. Therefore, option (C) is incorrect. (D) Both of them a re not correct. Only Joish is correct. Therefore, option (D is incorrect. (E) Both of them are not incorrect. Only Ronald is incorrect. Therefore, option (E) is incorrect.     Fill in the blanks: 1. The _4_____ controls and coordinates the use of the hardware among the various application programs for the various users. 2. ________ converts the HLL program to machine language. 3. ________ language processor converts the program written in assembly language into machine language. (A) Operating system, Compiler, Assembler (B) System Software, Interpreter, Compiler (C) Language processor, Assembler, compiler (D) Operating system, Assembler, Interpreter (E) System Software, Compiler, Interpreter   Answer: (A) Correct Option: (A) Options given in (A) are correct. Incorrect Options: (B) Options given in (B) are incorrect. Therefore, option (B) is incorrect. (C) Options given in (C) are incorrect. Therefore, option (C) is incorrect. (D) Options given in (D) are incorrect. Therefore, option (D) is incorrect. (E) Options given in (E) are incorrect. Therefore, option (E) is incorrect.