What is an "Instruction lookup table" ? in Assembler program

[osdevkid]

Dear Guys,

I am go throughing DASM assembler code, understanding code is very difficult, I cant able to find the best tutorial for "Assembler".

Tutorials available for "Assembly Language" but not for "Assembler", Can anybody help me to find out good Assembler guide.

Meanwhile, I want to know about the term "Instruction lookup table", how it is useful in Assembler.

Pls help me guys...

[NickJohnson]

So are you trying to write an assembler, or to write in assembly?

[osdevkid]

Actually, I am not trying to write an Assembler, I am trying to understand Assembler.

[hailstorm]

Learning assembly isn't so hard, but to learn it, you should create some programs using assembly yourself.

A good place to start would be this: http://en.wikipedia.org/wiki/Assembly_language
Also follow the reference which will give you a basic insight in assembly language.

Success and just start to program in assembly!

[osdevkid]

Hi hailstorm,

Please read my quote in first post.

I am go throughing DASM assembler code, understanding code is very difficult, I cant able to find the best tutorial for "Assembler".

Tutorials available for "Assembly Language" but not for "Assembler", Can anybody help me to find out good Assembler guide.

[NickJohnson]

So you're going through the code of DASM to understand it? There are definitely not going to be tutorials for reading the code of a specific obscure assembler, or even any assembler. Your best resource is definitely going to be documentation and comments in the code (if there are any...)

To answer your question, the instruction lookup table is part of the assembler that decides which machine code instruction to produce given which instruction you type. Essentially, it describes the target architecture.

[osdevkid]

Dear NickJohnson,

Assembler will convert ASM code to Machine code, it is target specific, it is true, however, Assembler does lot of things, like arranging "code/data/bss" segments, creating symbol table, adding relocation information and etc., It is very important to understand your assembler/compiler to develop our own OS.

DASM is a free assembler, however I can not able to find a tutorial for that, that is why I am looking for other assembler or related concepts (not assembly language concepts) .

If you know any good assembler tutorial recommed pls.

[NickJohnson]

Assembler will convert ASM code to Machine code, it is target specific, it is true, however, Assembler does lot of things, like arranging "code/data/bss" segments, creating symbol table, adding relocation information and etc., It is very important to understand your assembler/compiler to develop our own OS.

True, but I think you're trying to go too deep into the mechanisms of the assembler. Even if you're writing an OS, you don't have to worry about precisely how the assembler and linker work until you're trying to do some pretty advanced stuff; for almost all purposes, you only need to understand how to use them properly.

DASM is a free assembler, however I can not able to find a tutorial for that, that is why I am looking for other assembler or related concepts (not assembly language concepts) .

Generally, there's some sort of explanation in the software's documentation, but it's not going to be anything step-by-step like a tutorial. There's no real way to format "how an assembler works" as a tutorial, so I doubt there is a tutorial out there on the subject.

[Thomas]

Hi,
DASM - that comes with the MMURTL right ?. Please do read the source code and figure that out. It is rather straight forward. It might serve you well in the long run as well.
One good way to understand is to build the debug image of the executable and then step through code when you have doubts.

--Thomas

[prasadjvv]

I have found some documentation in the following compressed file for DASM
http://www.atari2600.org/DASM/DASM22004.zip

Not relevent to what you are looking for? Post more details about DASM which you are using.

Note:
If you are looking for some assembler's manual which may be different from DASM, you can read http://www.nasm.us/doc/nasmdoc0.html which is about NASM, specific to Intel Architecture. But I don't think it is much useful as different assemblers have different ways of programming.

[osdevkid]

Dear prasadjvv & Thomas

Thanks for your reply.

I have also found some useful document about Assembler

http://www.scifac.ru.ac.za/compilers/

This link talks more about compiler, however the pdf file "pdfvers.pdf" has two chapters about Assembler, I have yet to read.

[djmauretto]

Tutorials available for "Assembly Language" but not for "Assembler", Can anybody help me to find out good Assembler guide

Intel Manuals are the best guide to assembly language
About the assembler you can try Fasm http://board.flatassembler.net/index.php