4. Assembly language

As you have seen, Machine code is quite difficult to work with as a programmer.

So to make things a bit easier, a language called Assembly Language was developed. This uses English-like commands that are easier to use.

For example the instruction to Add is

ADD A,B

The instruction to Subtract is

SUB A,B

and the instruction to move data from one part of the CPU to another is

MOV AL, EX

It is still a 'Low Level Language' because most of the instructions translate into only one Machine Code instruction.

Before instructions written in Assembly Language can be used, they must be translated into machine code by a programme called an Assembler.

Advantage over Machine Code

• Easier to remember the commands
• Easier to fix (debug) when the wrong instructions are written
• The same computer programme written in Assembly Language can be used over a range of computers as an Assembler for each type of computer chip is available.