Chapter 7 - Programming

Input or output

Process, doing something

Instructions represented in binary used by the CPU

An opcode: tells the processor what to do An operand: tells the processor what to do it to

The processor’s logic circuits

A programming languages which resembles a natural language, each instruction translates to many machine instructions. It is problem based rather than machine based.

CPU does not understand high level code, therefore it must be translated into a set of machine code instructions

Software which translates mnemonic instructions in assembly language to machine code

Converts the whole high level code into machine code before running it

Converts the code one instruction at a time, running each instruction before translating the next

Code written by the programmer A compiler turns source code into object code which runs independently to the source code

Precise and direct instructions to the computer hardware Difficult to code and limited range of commands available

Code runs quickly once compiled Difficult for others to modify without access to source code Initial compilation can be slow Errors are generated for all the code at once - difficult to debug

Executes one statement at a time so easy to debug Code can be developed and tested in stages More portable as the code will run anywhere as long as there is an interpreter available Interpreter takes up space in memory Code executes slowly Interpreter needed on target machine

Translators usually include an integrated development environment o help programmers

Source code editor Error diagnostics and debugger Run time environment Translator (compiler/interpreter) Automation tools

A text editing area organises the code including indenting structures and colour coding command words, variables an comments

Warnings identify potential problems with the code and listing errors found in the code

Allows the developer to run the code during development to check for logical errors

Compiled or interprets the source code into runnable machine code

Auto documentation: tracks variables, sub routines and comments as the project is developed ( produce text file used for maintenance) Wizards: autocomplete woe as it is typed

A named storage space reserved in memory to store the value associated with that variable name or constant

Whole number values, positive or negative with no decimal part

Numbers with a decimal part or factional part