System Software

System Software

1. Operating System

   • A set of programs that lie between the hardware and the software
   • Has many different functions such as
     • Resource management
       • Manages all the computer hardware including... the CPU, memory, disk drives etc
         • The CPU
         • Memory
         • disk drives
     • Provision of a user interface
       • Enables the user to perform many different tasks, such as...
         • Running application software
         • Changing settings on the computer
         • Downloading and installing new software

2. Utility Programs

   • Designed to optimise the performance of the computer or perform tasks such as..
     • restoring corrupted files from backup
     • Compressing or decompressing data
     • encrypting data before transmission, providing a firewall
   • For instance...
     • Disk Defragmenter
       • Files which have been split up and spread over the disk will be recombined in a single series of sequential blocks on the disk
       • Makes reading the files on the disk quicker
       • On Windows, the software Optimise Drives runs automatically on a weekly schedule
     • Virus Checker
       • Checks the hard drive and (depending on the protection offered) incoming emails and downloads for viruses
       • Some operating systems come with built in anti-virus software

3. Translators

   • Programming language translators fall into three categories...
     • Compilers
     • Interpreters
     • Assemblers
   • Translates the source code written by the programmer into machine code

4. Libraries

   • Ready Compiled programs which can be run when needed
   • Grouped together in a software library
   • In Windows, these often have a .dll extension
   • Most compiled languages have their own libraries of pre-written functions