At the centre of your Commodore 64 microcomputer is the 6510 microprocessor which is responsible for coordinating and controlling every single thing your Commodore 64 does while it is switched on. The microprocessor can be programmed in its own language­ machine language-and that is the aim of this book, to teach you just how to program your micro at its very own machine level. The text assumes that you have some knowledge of CBM BASIC but know absolutely nothing about machine code. I have tried very hard to write in a non-technical language and to set the chapters out in a logical manner, introducing new concepts in digestible pieces as and when they are needed,
rather than devoting·chapters to specific items. Wherever possible practical programs are included to bring home the point being made, and in most instances these are analysed and the function and operation of each instruction explained.

Commodore 64 Assembly Language is completely self-contained, includes a full description of all the machine code instructions available and suggests suitable applications for their use. After a 'bit of theory' in the opening chapters, the main registers of the 6510 are introduced and descriptions given of how , when and where machine code routines can be entered.There isalso a simple machine code monitor program to facilitate the entry of such routines.

After discussing the way in which the 6510 flags certain conditions to the outside world, some of the modes of addressing the chip are described. Machine code addition and subtraction are introduced and the easiest ways of manipulating and saving data for future use by the program and processor are described. Machine code loops (equivalent to BASIC's FOR . . . NEXT . . . STEP) show how sections of code may be repeated, and subroutines and jumps take the place of BASIC's GOSUB and GOTO. Also included is a look at some of the more complicated ·procedure s such as multiplication and division using the shift and rotate instructions, and producing sprites in
machine code illustrates just how fast real time graphics can be!

The Kernal is a very important part of the Commodore's set-up, so no expense has been spared in explaining every Kernal routine in detail. Practical examples show how the more important ones can be used.

Finally, a comprehensive set of appendices provide a quick and easy reference to the sorts of things you'll need to 'want to know quickly' when you start writing your very own original machine code programs!