Hello, I am learning ASM, but I have a problem: The tutorial page use TASM syntax. I tried to convert the following code to FASM. But, I can't do it.



Thanks for answer(I'm not a native english speaker)

Assuming the original code is correct, you can simply remove the "ptr".

Thanks cod3b453!!! I will apply your suggestion.

I returned to the forum because my code did not work. I have the following code fragment that not works:



When I try to assembly it with FASM, it says: Invalid Operant.

I don't know why. Can somebody help me???

There's no such instruction encoding for cmp. You will need to make one of those parameters a register.

More information on instructions can be found from Intel Volume 2 or AMD Volume 3 manuals.

Thanks. Where I can get that manuals??? From the Official page?? Or there's better manuals out there??

You can have:

cmp mem,immediate
cmp mem,reg

But you can't have:

cmp mem,mem ;x86 encoding doesn't support this

jhonny6721, your 1st post has a very respectable signature, but your 1st and 3rd posts suggest you are learning asm at least partly for the purpose of creating malware, or perhaps mutating existing malware. True?

Revolution, thanks for telling me that it is not possible to compare two variables in memory. And neville, I have to admit that I'm reading some assembly codes, and some of them are about how computer viruses work. I do not do evil purposes, only research