Assembly Language Programming Tutorial – 21 – Copying Smaller Values to Larger Ones

All references in this video came from:
Assembly Language for x86 Processors (6th Edition)

Brought to you by

Rasim from give us another tutorial on Assembly Language Programming . In this tutorial Rasim talks about how to copy smaller values to larger ones. Example: (mov ax, cl) won’t work because “ax” is a 16-bit register and “cl” is a 8-bit register, but Rasim show us a way around it.




Google Plus:





Sebastian Puerta Hincapie says:

Mr. Muratovic took the time to create a crash course for everyone that needs a quick hands-on application and yet he gets so many complaints. I’m assuming he has a certain time limit for each lesson but at least he’s touching on a lot of different methods and implementations that can be helpful. Don’t watch it, if it bothers you that much or simply read the book.

Stephen Reynolds says:

It seems to me that really all you are doing is moving an 8-bit value into an 8-bit register. Not actually moving an 8-bit value into 16-bit register AX. Yes, you are zeroing out AX but not actually moving var1 to AX. Since var1 is 8-bit and AL is an 8-bit register then there should’nt be any issue making this move in the first place. How do you actually move 8-bit var1 into 16-bit regester AX with only using MOV, not MOVZX or MOVSX? 

Rafael Scheiner says:

im having trouble with div because i need for the user to input both numbers and just show the answer the problem is, the register that receives the number is AL, how will i move the value of AL to AX?

Joseline Cisternas Viveros says:

¿Como puedo pasar un valor de ax a bx, utilizando ciclos, copiado bit por ciclo, partiendo por el menos significativo.?

espero me puedas responder.


Khalil Al-Nokhatha says:

Why complicating things when you have MOVSX & MOVZX instructions?

Phea utube says:

You should explain each tutorial in detail not just reading it, beginners find it very hard to catch up but thank you for your effort.

Hadi a says:

thank you

herr ste says:

another example of this:
var1 dw 1234h
xor ax,ax
mov al,byte [var1] ;copy 34h to al
mov ah,byte [var1+1] ;copy 12h to ah

Dzz says:

Where are you from?

 Write a comment


Do you like our videos?
Do you want to see more like that?

Please click below to support us on Facebook!