System Software

System Software

1. A type of software that controls the computer's hardware

2. Provides an interface between the user of the computer and the hardware

3. Operating System (OS)

   • A type of System Software
   • Said to provide a Virtual Machine
     • Hides the complexities of the hardware from the user
       • No need to understand where the date is being saved on the disk
   • Allocates memory between the different programs that are open at the same time (Multitasking)

4. Multitasking

   • A technique used by the processor which makes it seem to us that many tasks are done at the same time
   • The processor does a small time slice for each task/program which, in reality, has resources such as memory and the processor being shared among all tasks
   • Splits the time it takes for each task to be executed

5. Drivers

   • A piece of software used to control as a piece of hardware
   • Allows a peripheral device to be connected to a computer and be used by the Operating System
   • Can get drivers for graphics cards, mouse, sound cars and network interface cards
   • Are OS specific and are regularly updated by companies

6. Peripheral Management

   • Peripheral - A piece of hardware not directly connected to the CPU e.g. Keyboard, Mouse
   • OS manages all peripheral devices connected to the computer - allows them to be disabled or drivers to be updated
   • e.g. Window Device Management

7. File Management

   • OS must identify where files are stored in long term storage
   • OS must know where the file is located (specific track, sector, surface address) to accurately find the file on the hard disk drive

8. Utility Software

   • Designed to do just one or two tasks
   • Interacts with the computers hardware
   • Built into the OS
   • Types of Utility Software
     • File Compression
     • Disk Defragmention
     • File Repair
     • Disk Copying
     • Disk Formatting
     • Disk Backup/ Restore
     • Anti-Virus

9. Compression

   • Reducing the size of the file by performing an algorithm on the original data
   • Lossess - The original file can be recreated as no data is lost
   • Lossy - Some of the original data is lost and cannot be recreated

10. Defragmentation Software

    • Groups fragmented files (broken-down/ scattered files) back toghether
      • Done normally when storage device is full

11. Encryption Software

    • Software which encrypts and decrypts data via the same key

12. Backups

    • Backups are done to restore any files/data/programs in case of a computer failure
      • Copies of data and/or software are taken regularly and usually stored in a different location
        • Backup Types
          • Full
            • A copy of all data and software on the Hard Disk Drive
            • Can also be a copy of the data and software transferred onto an external storage device; this makes it kept at a different location
            • Takes a long time to complete (usually overnight)
            • Recovery of data and software takes a long time as all data and software is being restored
          • Incremental
            • A full backup is made initially
            • Files which have only been changed since the last incremental backup are copied (done daily)
            • Much faster to complete than full backups
            • Takes much longer at restoring than a full backup because additional incremental backups would have to be restored after the full backup restores data