OS SYSTEMS

OS SYSTEMS

1. Why do we need them

   • Machine code is different for each hardware
     • Keyboard
     • Controller
     • Touch Screen
   • Each PC is different combination of CPU, RAM, GUI.
   • Would take too long for the programmer to write code for all these different parts
   • Helps handle multitasking, interupts and file management

2. What to they manage

   • CPU
     • While the CPU is waiting for instructions to be executed it can be doing other things. Multitasking, an OS makes this possible
       • Multitasking makes it look like the CPU is doing two things at once, but its actually just intertwining the instructions
     • It also controls Interupts, when something is more inmportant than something else
       • Mouse Movement
       • Error Message
       • It backs up the previous task and starts the more important one
   • RAM
     • Splits the RAM into different sections for the different applications too use
       • Therefore a game cant access your password
   • Backing Stores
     • Backs up files to the cloud, tape or disk
     • OS quite often do this automatically
   • Peripherals
     • For different devices different instructions are needed in order form them to translate to the language of the application
       • Xbox Controller
       • Keyboard
       • PS Controller
   • Drivers
     • For each new device, the company need to create drivers which include the instrucions for the translation
       • For example the new Xbox controller needs new intrustions so microsoft will need to make a driver
   • Security

3. Interfaces

   • Graphical User Interface
     • Used by most PCs and Phone
     • Graphical interpretations of the commands are shown to the user
     • Very easy to learn and use
     • Programmes often run in different windows and multiple can be shown at the same time
   • Command Line Interface
     • Text based
     • User types commands and text is returned
     • Very lightweight and robust. Come with all GUIs