When a brand new computer comes off the factory assembly line, it can do nothing. The hardware needs software to make it work. Are we talking about applications software such as wordprocessing or spreadsheet software? Partly. But an applications software package does not communicate directly with the hardware. Between the applications software and the hardware is a software interface - an operating system. An operating system is a set of programs that lies between applications software and the computer hardware.
The most important program in the operating system, the program that manages the operating system, is the supervisor program, most of which remains in memory and is thus referred to as resident. The supervisor controls the entire operating system and loads into memory other operating system programs (called non-resident) from disk storage only as needed.
An operating system has three main functions: (1) manage the computer's resources, such as the central processing unit, memory, disk drives, and printers, (2) establish a user interface, and (3) execute and provide services for applications software. Keep in mind, however, that much of the work of an operating system is hidden from the user. In particular, the first listed function, managing the computer's resources, is taken care of without the user being aware of the details. Furthermore, all input and output operations, although invoked by an applications program, are actually carried out by the operating system.
Post reading activity
Task 1. Answer the following questions.
1. What is an operating system? 2. What system provides an interface between applications programs and the computer hardware? 3. Is the work of the operating system always obvious to the user? 4. What is the most important program in an OS? 5. How does the supervisor program work? 6. What is the difference between resident and non-resident programs? 7. How can you explain the meaning “command driven”? 8. What is a command prompt? 9. How can you define Unix? What versions is it available in? 10. What do you know about GUI? 11. What are three main functions of an operating system? Give some examples to prove your answer.
Task 2. Give the Russian equivalents for:
load, available, multi-tasking computer, user, user interface, word processor, non-resident programs, command-driven, execute, abbreviations, multi-user mainframe computer, printing files, blank, graphical user interface.
Task 3. Find the English equivalents for the following Russian word combinations.
a. spreadsheets; b. operating system; c. computer hardware; d. software package; e. resident program; f. mainframe computers; g. icon; h. applications programs; i. supervisor program; j. wordprocessor; k. to click; l. command prompt.
Task 4. Mark the following as True or False.
1. The work of the operating system takes place in the background and is always obvious to the user. 2. The most important in an OS is the supervisor program. 3. Programs that remain in memory while the computer is in use are known as non-resident programs. 4. The screen is usually blank except for a symbol (e.g.$) which acts as a command prompt. 5. OS commands are usually long words. 6.Unix is a command driven operating system used in all sizes of computer but mostly large multi-user, multi-tasking mainframe computers. 7. The hardware doesn’t need software to make it work. 8. An application software package communicates directly with the hardware. 9. An operating system has only two main functions.
Task 5. Match the terms in Table A with the statements in Table B.