First, let me introduce this book by telling you what I will teach you. By the end of this book, you will have enough information to write any text based console program in the form of a 16-bit DOS (Disk Operating System) ".com" file.

The ".com" file was a format used by all version of MS-DOS, and even supported on Windows up to XP. It has no header information and is limited to 64 kilobytes of memory. Rather than viewing the limitation as a weakness, I view it as a strength because it forces me to be a better programmer and squeeze the most out of every byte.

## Required Knowledge

To get the most out of this book, some background on the Binary and Hexadecimal numeral systems is going to be helpful, but this is not strictly required because I will be providing functions you can use in your code that will convert between decimal (base ten), binary (base two), and hexadecimal (base 16).

However, I would say that experience in at least one programming language is necessary for an understanding of terminology like "arrays", "pointers", "addresses", "integers", "floating point", etc. I recommend the C Programming Language as a start. C++ is also a good starting language but tends to abstract details away that directly apply to Assembly Language, which is the lowest level a human can go for understanding a computer.

## Low Level

Low level is a term that confuses people. People think something high level is better than low level. In simple terms, humans consider themselves superior to machines and therefore think themselves higher or more important because of their abstract though.

A computer thinks only in terms of numbers. A computer may not understand "high level" abstractions such as love, religion, philosophy, etc, but that is not its job. A computer must add, subtract, multiply, and divide. These are the four arithmetic functions which many human struggle to do.

Therefore I ask you, between a human and a computer, who is really low level or high level? In the age of Artificial Intelligence taking over human jobs and beating humans at Chess, we would all do well to take this question seriously.

I wrote this book because I think like a machine and I hope to help others think this way because it is the best way to learn programming and control your computer by writing Assembly Language programs or to go back to your favorite programming language with a greater understanding of why things work as they do.