I have been programming with C#, BASIC, C, CPP, PHP and HTML for a while... i never saw anything quite like assembly.. its complex nature has grabbed my intrest. I have been looking at code and registers for about a day now and im not feeling that i made any progress learning this very capable language. If someone would like to IM me, or better yet, make this thread serve as some type of walkthrough for Assembly Code that is explained in a way a C# programmer would understand, i'd appreciate that. Im sure other people in my situation would to. Basically my problem is that nothing makes sense here. i understand im working with the processor, and im getting an idea of how low of a level Assembly actually is... but thats not enough. I want to understand the syntax. Thanks in advance

Look at some Hello world programs and other examples and try to enhance them. Try some math:

iceman: I suggest starting with 32bit windows assembly, it is somewhat easier to grasp at the beginning than 16bit real mode (DOS) assembly.

I think looking into how instructions are encoded would explain a lot to you. For example why you can use certain combination of parameters, but not others, etc.

In C#, you can do anything that makes sense syntax-wise, and compiler will translate it into series of step with desired results. But in assembly, you are not limited by "artificial" syntax. In assembly, every statement must correspond 1:1 to one CPU instruction, so you are limited by the processor architecture, not by the language.

Because of that, you cannot do certain things which would make sense syntactically, like move from memory to memory directly ("mov [var1], [var2]").

Another new concept might be memory, which in assemby beheaves strictly like array of bytes. Closest to this was probably C, not sure how much you spent with it. This array is indexed by number called "offset" or simply "pointer". But, in assembly, this pointer is not anything special, like in C. It is just plain number like every else, and it's only on you whether you use the number for arithmetics, or as index to "memory array", or both. For example:


Another things which could be troublesome until explained is accessing various parts of register. For exampe EAX is 32 bit register, whose lower 16 bits are called AX. Lower 8 bits of AX is called AL, and upper 8 bits of AX is called AH. You can access these register parts directly:

ah ok. i see how eax works. thank you. that did help a lot.