WHAT’S IN THIS CHAPTER?
Assembly language is the most basic programming language available for any processor. It is a collection of commands, or instructions, that the processor can execute. A program is a list of instructions in a specific order telling the computer what to do. Just like a calculator, you can tell a processor to take a number, to multiply it by 2, and to give you the answer. However, you need to supply some more information; you need to tell the processor where to get the number and what to do with it afterward.
A processor runs machine code, and machine code can be specific from one processor to another. Machine code written for a 6502 cannot, and will not, run on a 68000. Machine code is a list of numbers that make no sense whatsoever to (most) humans. To make the programmer’s life a little more bearable, Assembly language was invented. Assembly language consists of words and numbers, and although it isn’t as easy to understand as the English language, it is much easier to understand than reading numbers or punch cards.
Assembly language enables programmers to write computer programs, telling the processor exactly what it must do.
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