Register ah is the high half of the low 16 bits. This can sound of tricky at first but soon as you understand the notation you can know how to pick out registers to use with your instructions. Its kind of you move stuff from places into the registers, and then use them in accordance with instructions, and then move the changes around to different places. But what were going to explain here is just inline assembly. You can create functions that pass variables that can be manipulated with inline assembly, you can do all kinds of neat stuff.
Lets explain the code.
If your interested in understanding the instructions further I suggest going and getting a guide to the instruction set. Jared Bruni heres a web page with a 32 bit assembler for windows and a whole section of tutorials. I always wanted to know about this. Theauthor of this article has been kind enoughto share it with you. If you have a criticism, please state itpolitely or it will be deleted.