sexta-feira, 4 de maio de 2018


Hi, IT folks, welcome to my blog! 
I´d like you feel free to read and contribute ideas here! 
Not only by writing your opinion about the text, but also by talking to your colleagues by replying to their comments.  Let´s build our knowledge together and have fun!

Read the text below, answer the questions and discuss with friends:

a. What difference is there between applications software and operating systems?
b. Why is the supervisor program the most important operating system program?
c. What is the difference between resident and non-resident programs?
d. What are the main functions of an operating system?


When a brand new computer  comes off the factory assembly line, it can do nothing. The hardware needs software to make id work. Are we talking about applications software such as word processing 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 nonresident) 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;
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.

Source: Oxford English for Information Technology
Eric H. Glendinning & John McEwan