Operating Systems

Operating Systems

1. Description

   • A computer will not run without an operating system, as it is the program that controls the running of the computer
   • When a PC is switched on, the first thing that happens is that the operating system is loaded into memory usually from the hard-drive. The computer is designed with a small amount of software on a ROM chip, which allows the computer to find the main part of the operating system
     • This process is called booting

2. An operating system can carry out the following functions

   • It loads and runs programs
   • It maximises the use of memory (RAM)
   • It handles inputs and outputs
   • If interuptions occur, then it handles them
   • It maintains the security of the system

3. Applications software is specific to a certain operating system and so cannot run under another one. For example, a Windows program could not run under a UNIX or Linux operating system