1. Standard Grade Computing SYSTEM SOFTWARE CHAPTER 19

2. Standard Grade Computing SYSTEM SOFTWARE System software is a collection of programs which help the computer to work properly. It includes the Operating system Filing system Translator programs General

3. Standard Grade Computing TRANSLATOR PROGRAMS A translator programs is needed because The computer only understands machine code i.e. binary = 0s & 1s e.g. 0110 1001 Humans understand English (high level language) It changes high level language into machine code General

4. Standard Grade Computing Common Features of High Level Languages Can help the programmer to solve problems Code is written using English words Programs are easier to read, write, update & debug Programs must be translated into machine code Private Sub Command1_Click() MsgBox "This program will sort a list of names into order" List1.Clear List1.AddItem "Joe" List1.AddItem "Mary" List1.AddItem "Alice" List1.AddItem "Mike" List1.AddItem "Pete" End Sub General

5. Standard Grade Computing Types of Translator Interpreter Translates 1 instruction at a time Translates program every time it is run (program runs slower) Easy to spot & fix mistakes (debug) as errors reported as they happen Interpreters always in main memory when the program is run Credit Source Code Single Instruction INTERPRETER Machine Code Get Next Instruction Report Errors

6. Standard Grade Computing Types of Translator Compiler Translates whole program at once A machine code version is produced called the object code Runs quickly as object code is run & no further translation is needed Errors are reported after the whole program has been translated. Credit Source Code Whole Program COMPILER Object Code Machine Code Program Report Errors

7. Standard Grade Computing Portability of Software A program is said to be portable if you can run it on different computer systems without any alteration. Programs written in machine code are related directly to the processor so are NOT portable Credit

8. Standard Grade Computing And there is more…. Tune in again to see the next exciting chapter