Sooner or later, many programmers find that they want to learn machine language. BASIC is a fine generalpurpose tool, but it has its limitations. Machine language often called assembly language performs much faster. BASIC is fairly easy to learn, but most beginners do not realize that machine language can also be easy. And, just as learning Italian goes faster if you already know Spanish, if a programmer already knows BASIC, much of this knowledge will make learning machine language easier. There are many similarities. This book is designed to teach machine language to those who have a working knowledge of BASIC. For example, Chapter 9 is a list of BASIC statements. Following each is a machine language routine which accomplishes the same task. In this way, if you know what you want to do in BASIC, you can find out how to do it in machine language. To make it easier to write programs in machine language called ML from here on, most programmers use a special program called an assembler. This is where the term assembly language comes from. ML and assembly language programs are both essentially the same thing. Using an assembler to create ML programs is far easier than being forced to look up and then POKE each byte into RAM memory. Thats the way it used to be done, when there was too little memory in computers to hold languages like BASIC or Assemblers at the same time as programs created by those languages. That old style handprogramming was very laborious. There is an assembler in BASIC at the end of this book which will work on most computers which use Microsoft BASIC, including the Apple, PETCBM, VIC, and the Commodore 64. There is also a separate version for the Atari. It will let you type in ML instructions like INC 2 and will translate them into the right numbers and POKE them for you wherever in memory you decide you want your ML program. Instructions are like BASIC commands; you build an ML program using the ML instruction set. A complete table of all the 6502 ML instructions can be found in Appendix A. Its a little premature, but if youre curious, INC 2 will increase the number in your computers second memory cell by one. If the number in cell 2 is 15, it will become a 16 after INC 2. Think of it as increment address two. Throughout the book well be learning how to handle a variety of ML instructions, and the Simple Assembler program will be of great help. You might want to familiarize yourself with it. Knowing what it does and using it to try the examples in this book, you will gradually build your understanding of ML, hexadecimal numbers, and the new possibilities open to the computerist who knows ML.

Website: http://www.atariarchives.org/mlb/