Greetings fellow calculator enthusiasts,

I have a TI-89T for programming and an HP-50g for math, and am considering purchasing a TI-Nspire CAS+ (for $50) for general math. Since you guys are quite knowledgeable about this kind of thing, and some members have a CAS+, I was hoping you could answer a few questions of mine.

What are the differences between the old CAS+ OS and the newer ones on the CAS Touchpad?

Since I am not concerned with always updating the OS on my 89T and 50g, I dont think I will care about being stuck on an old OS on the CAS+. Am I wrong?

Is the hardware any different from the non-prototype CAS Nspires?

The reasons I am considering "upgrading" from my TI-89T are its lack of mathprint, tiny screen (even when compared to the *crappy* screen of the HP-50g), and general slowness compared to the 50g. Will I be disappointed with the CAS+'s "improvements" over the TI-89T?

Thanks for reading

The old Nspire CAS+ prototype OS 1.0 can't open documents created by more recent production TI-Nspire OSes.
The TI-Nspire CAS+ prototype OS 1.0 can't exchange data through USB with production TI-Nspire.

And nobody has been able up to now to update the TI-Nspire CAS+ prototype OS 1.0...


If it's a money problem, you can find TI-Nspire CAS ClickPads allmost as cheap as TI-Nspire CAS+.
You'll be able to do much more on them...

Yes, it has some serious bugs. The calc will sometimes fail to turn on the screen, making you think the batteries are dead while they're draining away.

The old Nspire CAS+ prototype OS 1.0 can't open documents created by more recent production TI-Nspire OSes.
The TI-Nspire CAS+ prototype OS 1.0 can't exchange data through USB with production TI-Nspire.

If it's a money problem, you can find TI-Nspire CAS ClickPads allmost as cheap as TI-Nspire CAS+.
You'll be able to do much more on them...

Wow! Thanks for the prompt reply, I guess the extra $20 for a CAS Clickpad is really worth it then. Any suggestions on where to get one besides ebay and amazon?

allso, if MP is all you're after, it pains me to say this (the MP oses have many programming-related bugs), but an 84+ with the latest OS has mathprint. 83+s don't though, unless you hack the OS (I think someone did it, but it causes problems)

The 84+ is still around and being updated? Pardon my lack of current knowledge on TI's calculator lineup, but is this because of the 84+ keypad for the regular nspire? I don't really understand why they would keep such an outdated calculator around for so long and still update the OS.

I really wouldn't recommended using a prototype CAS+ for general math. It's really only good if you're into hacking and stuff. But if you don't mind having a Casio calc I would highly recommend the Prizm. It offers many great features and a color screen for $130 from stores. (you could probably find a better deal on ebay) and I know you wanted a calc for general math, but we all know that at some point you are going to want put some games on there. And the Prizm has the advantage of being more open to development than the nspire. (especially the prototypes) )

Thanks for the warnings! I would get a Prizm, but I don't really care for the color screen (battery life is more important to me). Also, even though I don't use it very often, the CAS on my TI-89T and HP-50g is really nice. I would hate to buy a new calculator without CAS. ( I also have a  Casio fx-9750GA+. Nice calc, but I rarely use it.)

Unfortunately, as someone who enjoys taking things apart to learn how they work, I am still somewhat interested in the CAS+. Does anyone know if the OS is encrypted (on the NAND Flash)? Has anyone tried to directly dump the OS from it?

Actually the Prizm does have a very long battery life. I've had my Prizm since Christmas now and I use it for at least one hour everyday. In that time I have not changed the batteries once.

Yes, significant work for trying to understand and reflash the CAS+ prototypes is currently underway, in another section of this forum and on the French-speaking TI-Bank forum. See, for example, http://ourl.ca/9688
The prospect of reflashing CAS+ prototypes with the OS of commercial CAS models seems bleak, though.

Yeah, based on the info from that thread replacing the CAS+ OS with one signed with the production keys would be difficult. In my post I meant something a little more direct then the RS-232 USB Comm. I was referring to the NAND Flash-ROM.


Its been quite a while since I had to solder onto SMT stuff.

Actually the Prizm does have a very long battery life. I've had my Prizm since Christmas now and I use it for at least one hour everyday. In that time I have not changed the batteries once.

Impressive. Is there a C compiler for it or is it ASM only?

Keep in mind the calc is not super documented yet, though, so so far the most that can be done is stuff like this:



Note, this runs 3 times smoother on a real calc than in the screenshot.

This writes directly to the LCD. Once people can write to a buffer then update everything on the LCD at once, it will most likely be much faster.