1.7 system software

1.7 system software

1. system software

   • systems software is a type of software that controls the system hardware
   • it provides an interface between the user of the computer and the hardware
   • an operating system is a type of systems software
   • operating systems
   • utility programs
     • anti-virus software
     • disk defragmentation tool
     • disk copier
     • data compression
   • device drivers
     • graphics card driver
     • network interface card driver

2. operating systems

   • provide an interface between the user and the hardware
   • they are said to provide a virtual machine

3. processor managment

   • the processor has to divide its time between processes
   • it may allocate a small "time slice" to each separate process

4. multitasking

   • by giving the processor a small time slice for each task means that all tasks appear to be executing at the same time
   • to the user it appears that we can multitask and have lots of programs open at once
   • in reality resources such as memory and the processor are being shared amongst tasks

5. user interface

   • how does the system interact with the operating system
   • command line interface
     • text based
     • e.g DOS, PI
   • graphical user interface
     • windows
     • icons
     • menus
     • pointers

6. memory managment

   • the OS allocates memory between the different programs that are open at the same time