operating systems

operating systems

1. interrupts

   • a method to immediately pause execution of all processes and execute a new one
     • hardware interrupt
       • triggered by hardware
         • mouse
         • keyboard
     • software interrupt
       • triggered by any application
         • warning box

2. CPU

   • multi-tasking
     • splits processor time between different programs, making them appear to run simulataneously
   • manages processor by allocating time to running processes

3. memory (RAM)

   • splits memory into pages to prevent programs from reading each other's data

4. backing store

   • manages backups of important data
   • cloud
   • local

5. peripherals

   • external hardware devices
   • drivers used to map OS codes to hardware codes
     • OS needs a driver to work with newer hardware

6. security

   • authenticates users and prevents access to restricted files

7. GUI vs CLI

   • GUI
     • Graphical representations of the computer’s functions
       • advantages
         • easy to learn
         • lots of information shown at once
       • disadvantages
         • uses a lot of system resources
         • complexity means there is more to go wrong
   • CLI
     • a text-based interface
       • advantages
         • few system resources required
         • easy to automate (commands can be stored in files)
       • disadvantages
         • hard to learn
         • difficult to compare outputs of different programs