What are the pro and cons of z80 Assembly and TI-BASIC. What is assembly mostly used used for? Where can I find tutorials to start learning Assembly?

First off, the most important con is the possibility of a lot of RAM clears if you don't know what you are doing. The main pro is it is usually faster.

But you need to make sure you have a nice idea of programming on a calculator in general before attempting assembly imho.

The pros and cons of TI-Basic versus Z80 ASM, eh?

Pros:
TI-BASIC: Easy to program, (reasonably) programmable on-calc (right out of the box), math-oriented if you want to write mathematical programs, debugging and learning by trial-and-error is reasonably safe.
Z80 ASM: Offers (mostly) direct control of the calc, executes very fast, freedom to design what you want.

Cons:
TI-BASIC: Slow, even slower if graphically-oriented, limited in what you can do with the OS. If you want to make a graphically intensive game... good luck with that.
Z80 ASM: Highly accident prone (crashes causes RAM clears or worse), (depending on the programmer) steep learning curve, disproportionate amount of code to do something rather simple if programming without libs, and more steps if you're using the preferred method of programming on a computer.

And I think that's about it. If you're wanting to explore the possibilities of Z80 ASM, stick with the Cemetech boards, put forth the effort in learning the language, and you'll get pretty far. You're going to want to pick an assembler and stick with it. I use TASM, but other people are using Spasm and Brass for theirs. Also, you're going to want references. "ASM in 28 Days" is a good tutorial to start you off with. You may also want a listing of the opcodes, which can be found on ticalc.org

If you're wanting to learn more about TI-BASIC, give Omnimaga a go. There's lots of support for that over there. You can also try TI Basic Developer for some comprehensive information.

Still, I'd invest in learning more about the graphing calculator and what it has to offer before picking any language. I'd also take a good look at what goals you have for programming these calcs, whether it be for math-related programs or for gaming. If you already have the calculator and the manual (and the necessary references), I'd suggest picking apart programs that other people have made and learn from those.

EDIT: You're also going to want to check out the IRC channels. They offer some pretty nifty help whenever you need it. For the Cemetech boards, just use the SAX chat located in the left sidebar, near the bottom. If you want to use your own IRC client, the network is irc.efnet.net and the channel is #cemetech

Iambian's post put it nicely, but also I'd recommend being pretty familiar with TI-BASIC (especially variables and other parts of the OS) before starting ASM.

Deep Thought your signature looks weird, a bug?

@rohi89 I would recommend HotDog's tutorial, easily found here or in Omnimaga.org

For what it's worth, I initially had some reservations about HotDog's tutorials. I was talking with someone who had read those tutorials, and found he had little to know grasp of the connection between decimal, hex, hex nibbles as text, and binary. Another reader seemed to have a severe lack of confidence with bitshifting and bitmasking, vital ASM concepts. That's not to criticize Hot Dog's tutorials; they seem to be designed mostly for those looking to write ASM games, and they seem to be accessible content-wise to a lower common denominator than tutorials such as ASM in 28 Days that seem to assume a higher initial proficiency with programming and low-level concepts like binary and hexadecimal.

@Iambian: I am disappointed that you wouldn't equally recommend Cemetech as a BASIC place of guidance; we've been guiding rohi89 on his BASIC up until now.

My bad. I've always seen Cemetech as an ASM-y sort of place. Good to hear that there's good help on TI-BASIC here too.

Now that I thing of it, I suppose the inclusion of the Celtic III and DCS libs sort of says it all. Sorry for doubting ya guys.

Also, I completely forgot about Hot Dog's tutorials...

No insult taken, I was just curious. Between myself, and Weregoose, and TIFreak8x, I think we have a decent two or three decades of TI-BASIC experience, and we have some quite talented BASIC coders that have only been here for a few years.