Operating Systems

Operating Systems

1. Peripherals (input and output devices)

   • a device that is attached to the computer
   • Operating systems require driver software
   • A device driver maps the operating system’s commands to the device’s commands

2. Printing

   • If I need to print a document, it tells the operating system to print it.
   • Operating system will spool the print job
   • This means my program doesn’t need to worry if the printer is busy or unplugged or out of ink.

3. Backing stores

   • Backing stores are storage devices used to keep backups of important files
   • The OS will make regular backups in the right format

4. File compression

   • File compression is storing data in a way that keeps the same information but uses less disk space
   • Operating systems can compress data as it’s saved and decompress it as it’s loaded, allowing more data to be stored on a device.

5. Disk de-fragmentation

   • Disk defragmentation involves re-arranging file fragments on a physical disk surface to improve load times

6. Memory (RAM)

   • In order to ensure there is enough memory for each program that is running, Ram is split into “pages”
   • This prevents programs from snooping on data from other programs.

7. Processes (multi-tasking)

   • Multi-tasking is where a processor appears to be doing two tasks simultaneously
   • Modern processors can execute 4 billion instructions every second.