This is my advanced assembler tutorial.


Im assuming you did the basicfreaking tutorial ok?

If not go back and read it or im comin to your house to beat the living 
Daylights outta you with a crow bar :)

Ok so maybe im joking


Ok so you know some basic assembler stuff, but now
we goin advanced.


OK, first off you should know that ASM doesnt compile itself.


you need a compiler.

I recommend tasm and  tlinker, which the shareware versions are on my  page for download





Ok when your program is done, youll have to

open tasm in DOS


(DOS  is the best operatign system ever, for programming that is. for games i prefer windows
on a personal note FF7 is the best game ever made)


Once in dis  you will type


TASM    Prog.asm      


where prog.asm is just needs to eb the source files name to if your source file is
named UFO.asm
itd be

tasm ufo.asm



then youll see a readout, like wether it got any errors, if it did get errors it emans theres a bug 
or imporperly done instruction in your code.

If all goes well you should get a nice .obj file to play with


then, in dos

type either tlink prog.obj /t   for a .COM program

or tlink  prog.obj for a EXE program...


you choose which one to use based on the stuff we learn now.


First  is the Entry point...



in your code when you start it starts out like this for a COM
file



.model tiny



this emans all code and data must be in one segment no larger then 64k



.code



indicates code sgement begins


org 100h


In memory the program will start at address 100h


CS:0100h.

thats thwere when loaded into memory itll start executing..


EXEs start at 0h


Ok now i mentioned segments it probaby makes you wonder what theya re


a segment is a 64k long piece of code ro data or both



sgements are in segment:offset form


0000:0000



this is segment #0 offset #0


when ever the second set of zeros reaches FFFFh (64k)
and increments yet another time then the segment part
the first set of zeros will go up one..


also segments are dsivided into types


CS = code sgement
DS = data segment
ES = extra segment register
SS = stack segment





the stack segment is for the extra memory .EXEs reserve in the form of a stack.

the stack is a blank location in memory for data its where the data from the push /pop instructions get saved and used from




Also you should knowthat the difference between .COM files and .EXE is that exes have a special EXE ehader whereas coms do not.
ill explain this in detial sometime.