I am new in assembley and I need a sample source or a tutorial about mul of big numbers
for example 10 disigts * 10 digits.
The tutorial is "can you do this on paper"?
Yes I can
What do you do mean ?
So write the steps out on paper, and think about turning it into operations you can implement on a computer.
So you start with 3*7, result is 21. The 1 is one part of the result, which you do something with, and the 2 is another part of the result which you do something else with.
Throw in a couple of loops, and you're nearly there.
An example of such case would be
where A has 25H and B has 65H and just use the MUL function to multiply both but you must only use A and B registers. The results will be saved in register A.