Hi!
Well, today I started to learn assembly! I found it very interestring, but difficult too. My first question is about registers! What exactly are they? For example if register ah has value 2, then I need to set ASCII code value for dl register and then use system call to display character who is stored into bl register. As far as I understand registers are like variables, but there is some difference that I don't understand. For example al register is something what controls what will be output of a program? Like:
if al = 2 then display text output
if al = 3 then for example do I/O to parallel port
if ....
Is it this way? And the bl is responsible what would be but out and other registers have other purposes?

And my second question! I try to add contents from one variable to another, but I have an error! Here is my code:


Thank you!

Registers are the part of your CPU = Central Processing Unit
it Contains ALU FPU in simple cases,
ALU Arithmetical & Logical Unit contains the registers
FPU Floating Point Unit contains the fpu stack 8*10 bytes (also these are somwhat MMX registers too)
32bit ALU contains 32 bit registers EAX EBX ECX EDX
each has a 16 bit lower part accessable simply by using AX BX ...
and these have lower and upper bytes accesable simply by using AL (low) AH (hi) byte BL BH ...
segment registers, which you can load a general purpose register in/out
in 16 bit mode: cd ds es gs fs gs ss
32 bit mode:
ESI EDI EBP ESP EBX EDX can be used as address pointer you can extend my post, this was a quick.

for example you can in 16 bit mode address a byte in memory like:

Thank you!

well i see your thread is already DUPE,

http://board.flatassembler.net/topic.php?p=18303

why do you post same question multiple times?