Very nice and simple proof.  How about a slightly harder one.  Why can you check divisibility by 3 or 9 by adding up all the digits of a number?

That's harder.

9^(2n) mod 10 = 1
and 9^(2n-1) mod 10 = 9.

It's the same thing with 2 - 2, 4, 8, 6, 2, 4, 8, 6, etc.

Because 9*9 = 81, and when you keep multiplying by 9, the last number will bounce between 9 and 1. So when the power is odd, it will be 9, when it's even it'll be 1.

Thanks!

wow!  That looks awesome, how did I not notice this before?

* yunhua98 wonders if another "Axe" is here...

Quigibo needs to watch his back now.

Well it isn't quite as fast  as Axe because it has to convert all of the numbers on the fly. The main difference between Axe and this is that ReCode is interpreted so most codes should be smaller than an Axe program. Plus, you can use assembly, BASIC, and ReCode in the same program

With that in mind, I think my goal over the summer will be to create an app that takes total control of the RAM and is solely an environment to create and execute programs. It will not use the OS whatsoever. The problem with that, though, is that I will need to have a way to eventually give control back to the OS (for linking and to use the calc as a calc )

Xeda, don't be modest, yunhua98 is right, this is looking pretty awesome.

Can you make an example with smoothscrolling?

Quote from: Scout on March 19, 2011, 07:36:27 am

It has already been released, he's working on a new version that works on 84+ Keypads and is better.

No, I don't think it's going to work on the Nspire, but it'll work on 84+(SE) calcs that don't have the extra RAM.

Oh, good enough

Quote from: Scout on March 18, 2011, 05:06:07 pm

Also, can an admin move this to News if you agree that it is OK?

I think it fits better here in the nDoom section, because those who are new and want to play nDoom are probably going to look in the nDoom section.

I have to agree with you now (where was my head back then?). Removed

Edited the post, everything is finished.

I just checked my signature and it was changed. So maybe the picture that is displayed on the website of the userbar generator displays the old userbar after editing. Don't know why though. Anyway, I guess my problem is fixed.

Great =D

Introductions
Gamers, programmers, and a lot of internet users recently found out about nDoom and everybody wants to play it.

Setting up nDoom on a TI-NSpire can be difficult, hence I decided to write this article/tutorial on how to install and set up nDoom for the TI-NSpire Touchpad (and Clickpad, but I'm focusing on the Touchpad).

What do you need
To run Assembly/C programs like nDoom on the NSpire you need a TI-NSpire, NDless, TI-Nspire™ Computer Link Software, a USB cable to connect your NSpire to your computer and nDoom.

Setting up NDless
I didn't mention one thing you need in the previous paragraph, on purpose, because I want to explain it in separate. nDoom only works with NDless 2.0, which only works with TI-NSpire Operative Systems 2.x. This is, the Operative Systems that will work are all the ones that are of the type 2.x. I recommend 2.0.1, since it worked perfectly for me in my Touchpad, but I think the others will work as fine.

The first thing you need to install (and I can't help you with it) is the TI-Nspire™ Computer Link Software. Anyone who has ever installed a program on their computer will make it through easily (press 'Next' a hundred times).
Note: This software is only available for Windows and Macintosh.

After installing TI-Nspire™ Computer Link Software, connect your calculator to your computer and turn it on. Then open the software and, hopefully, a dialog will show up asking you to confirm which calculator you want to connect to. Connect.

Now you need the OS 2.0.1 (if you don't have it already, and you can check which OS you have by, in your calculator, going to the definitions menu and pressing State, this shouldn't be too hard). In case you don't have the OS you need, you can get it here. More OSs can be found here.

Now browse to the folder where your .tno file is, and drag and drop it to the Computer Link Software:



A popup will ask you if you really want to install the OS, do not disconnect your calculator until it is installed. The progress bar starts on the computer but will keep on to the calculator later.

Now that you have the proper OS you can install NDless. The version I used can be found here. It worked for me, but if you want the latest version of Ndless, you have to go here and download the 'latest' folder.

Whichever version you use, transfer the following files to your calculator (the same way you transferred the OS):
ndless_resources.tns;
ndless_installer_os-2.0.1.tns; //This may depend on your OS, but if you did just as I said in this tutorial, this is the one

Setting up nDoom

While it is true that nDoomis still beta, an 'executable' and very stable version of it is available. You can find it here.

Transfer all of the files in the folder downloaded (after extracting them of out of the .zip) to your calculator, the same way you did with the OS and NDless.

Now you have to unplug your calculator from the computer, but check if you have the ndoom_b1.tns and doom1.wad files on it. Recheck if you have the ndless installer and resources files.

Don't forget to unplug.


Really.

Now, hopefully, you have everything you need. Open your calculator, find the ndless_installer_os-2.0.1.tns file and open it. If everything is OK, a 'Sucess' message will show up and you can then open ndoom_b1.tns and play nDoom!

If the screen goes crazy, check if you have ndless_resources.tns on it (it happened to me).
If still not working, retry the tutorial or respond to this topic, since me or someone else can help you.

Before, you can even check these links:

http://ourl.ca/9206;
http://ourl.ca/7717;

Thanks to...

Thanks to the NDless development team for creating NDless and making an awesome readme.txt (I read it!) which thought me how to do this.
Thanks to Mrakoplaz for creating nDoom.

Very nice Stefan, it looks great, I love the screenshot, I think the game really gives the user the chance to do anything they want.