Omnimaga
Calculator Community => Other Calculators => Topic started by: Illumio on December 28, 2011, 03:15:40 pm
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I own a TI-Nspire CX with OS version 3.0.2.1793.
On my calculator I notice that it recognizes the CX CAS only commands and yet will not execute them (meaning that this calculator has something alike or the same as the CAS, yet has the CAS functionality disabled).
So yesterday, I searched around on the internet and wound up eventually on this site and read a forum post that was similar to this one asking if there is a way to have the CX CAS OS working on the CX. However, that post was old and hadn't been updated in a while for the newer OSes.
I also read that the most likely way to get the CX CAS OS to be loaded onto the CX would be with Ndless version 3 (which is in alpha stages or something along) and OSLauncher (which also seems outdated).
So my question is the title of the forum post: is there a way to have a TI-Nspire CX loaded with the TI-Nspire CX CAS OS? Is it possible at this moment in time? ???
Also if it is possible, would there be a way, once the OS is installed, to uninstall the CX CAS OS so that I could use it on any "high-stakes" exams I 'll have in the future so that my calculator is applicable? (What I'm thinking is that if there is a way, then just install the CX OS over the CX CAS OS).
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is there a way to have a TI-Nspire CX loaded with the TI-Nspire CX CAS OS? Is it possible at this moment in time?
Short answer: it has not been demonstrated, AFAWCT :)
Also if it is possible, would there be a way, once the OS is installed, to uninstall the CX CAS OS so that I could use it on any "high-stakes" exams I 'll have in the future so that my calculator is applicable? (What I'm thinking is that if there is a way, then just install the CX OS over the CX CAS OS).
OSLauncher does not permanently install the CAS OS, it merely hot-launches it (and often fails to, for some reason nobody has bothered to investigate). The Press To Test (PTT) mode triggers a reboot and therefore undoes the effect of OSLauncher anyway, so you wouldn't have to do anything yourself, for your calculator to be usable in standardized tests :)
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Thanks for replying quickly. Also can you give the long answer to the first question you answered?
So after PTT does that, I would, after the test and after I exit PTT, just relaunch OS Launcher (hypothetically since we don't know if there is a way to get OS Launcher to work on the CX series)?
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not yet, but when ndless 3 is released probably
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not yet, but when ndless 3 is released probably
Does that seem as though it could happen soon, or does it seem as if it is still along shot?
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I dont know ,but ExtendeD seems to be working at a fast face so maybe late January or Febuary earliest (I think
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Sorry if I seem clueless here but what is "ExtendeD"?
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Sorry if I seem clueless here but what is "ExtendeD"?
The guy who is making Ndless
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Well, that would be great if it came out in late-January to February. Hopefully TI won't detect it quick and make an OS Patch update.
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Ndless is software that allows third party C and ASM code to run on the Nspire series, and the OS launcher must be run through Ndless. Welcome to Omnimaga by the way! =)
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Ndless is software that allows third party C and ASM code to run on the Nspire series, and the OS launcher must be run through Ndless. Welcome to Omnimaga by the way! =)
Thanks! Also I read up a lot last night before I posted so I wouldn't be too much out of the loop.
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Well, there's no longer answer to "is there a way to have a TI-Nspire CX loaded with the TI-Nspire CX CAS OS?" than "it has not been demonstrated" :)
Hopefully TI won't detect it quick and make an OS Patch update.
But they will. There's no doubt that TI will patch the vulnerabilities: they did, each time, in the past.
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Also we need to be careful about releasing tools that allows a CAS to run on a non-CAS, because if it looks too easy for the average calc user, this could cause problems with TI.
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Also we need to be careful about releasing tools that allows a CAS to run on a non-CAS, because if it looks too easy for the average calc user, this could cause problems with TI.
Maybe add it as a hidden feature of a program?
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Oh I meant the documentation to achieve such thing. Or programs like RunOS. There's a reason why RunOS was never released.
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Well, OSLauncher was released, and it's a superset of what was indicated by the animated screenshot showcasing RunOS :)
But indeed, the important part of the source code (five C statements) is intentionally scarcely commented, and OSLauncher does not deal with hot-patching the OS before launching it (in a way similar to what tiosmod+amspatch does on the computer side).
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So we just need to keep the way of installing the CAS OS, when it's figured out, on the down low. That shouldn't be too hard to do. We just need it to be a select few who know (mainly people on this form and TICalc), right?
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Basically direct instructions on how to run a CAS on a non-CAS just need to not be easy to figure out or find on public forums, otherwise the owners of that forum could get in legal troubles.
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The "install the CAS OS" words usually refer to permanent install, as opposed to hot-launching ala RunOS/OSLauncher.
And if it were easy enough to do, it would probably have been done in the two past years ("plop from inside" was showcased on December 30th, 2009) ;)
The most obvious solution, for achieving permanent install, is factoring the public RSA signing keys used by TI (especially that of the boot2) to deduce the private key. But factoring the Nspire's RSA keys (1024-bit keys on the Clickpad & Touchpad, 2048-bit keys on the CX) is several million times harder than factoring the TI-68k & TI-Z80 512-bit RSA signing keys. This shifts the factorization problem from
something a single quad-core computer can do in less than a month (512-bit RSA key)
to
something which even the leading-edge researchers of the domain, equipped with academic resources amounting to hundreds of computers for years, haven't done yet and are unlikely to do before years (1024-bit RSA key)
This is assuming that
1) the only algorithm which is not hopeless for the task, named Number Field Sieve, is used for the factoring work;
2) the closed-source implementations made by these researchers are used; to date, two years after the factorization of RSA-768, the open-source implementations are not able to replicate it, because there have bottlenecks on basically all five steps of the factorization, which the leading-edge programs have eliminated by now.
IOW, the solution of factoring the RSA signing keys is completely ruled out - it would be like winning at multiple (or even many, in case the hopeless trial factoring is used) lotteries :)
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Also if we managed to factor 0.1% of the 2048 bit keys, TI would immediately switch to 4096 bit keys.
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But they can't change the hardware ones. ie boot 1, which means the boot 2 will always be constant. We'll just see another calc model.
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Woop! Ndless 3.1 Beta is released! So what to do now with this topic?
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There's nothing new :)
OSLauncher has not been demonstrated on the CX (CAS), AFAWCT. It may be more, or less, reliable than on Clickpad / Touchpad Nspires... we don't know :)
For updated versions, the structure of the core of OSLauncher (few C statements, posted below) shouldn't change. But the code needs work in at least two directions:
* porting from the Ndless 1.7/2.0 API to the Ndless 3.1 API: replacing show_dialog_box2 with the appropriate equivalent. That should be trivial;
* adapting to the CX hardware. For one thing, one of the C statements I posted below will have to change; maybe it's enough. The thing is, I'd rather someone else - specifically, someone with more than one CX calculator - do the testing ;)
[EDIT: add note about CX porting work, make a bullet list.]
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OSLauncher does not permanently install the CAS OS, it merely hot-launches it (and often fails to, for some reason nobody has bothered to investigate). The Press To Test (PTT) mode triggers a reboot and therefore undoes the effect of OSLauncher anyway, so you wouldn't have to do anything yourself, for your calculator to be usable in standardized tests :)
I have done some tests with OSLauncher and I found out that it freezes when you touch the touchpad while launching or start OSLauncher with the touchpad-click instead of enter.
When an OS is launched with the enter-key, I have never experienced any problems. Maybe this helps you to find the bug ???
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It may indeed mean something... but actions on the touchpad (or anywhere else) shouldn't matter, because the core of OSLauncher runs with interrupts disabled (it's the first of the few C statements I mentioned above), so I'm confused as well...
// Killing all interrupts is necessary (exercise for the reader: why ?)
*((uint32_t *)0xDC00000C) = 0xFFFFFFFF;
__builtin_memset((void *)0x10000000, 0, 0x02000000);
// Useful ?
__builtin_memcpy((void *)0x10000000, dest, ziphdr.usize);
// Useful ?
__builtin_memcpy((void *)0x00000000, (void *)0x10000000, 0x40);
// This is also necessary (exercise for the reader: why ?)
*((uint32_t *)0xC000001C) &= ~((1 << 0) | (1 << 11));
// Launch the OS.
asm volatile(
".arm \n"
"mov lr, pc\n"
"ldr pc, =0x10000000\n"
);
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So I guess the only answer for now is that only time will tell.
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Even though I don't know that much, I'll try do your exercises :D
// Killing all interrupts is necessary (exercise for the reader: why ?)
*((uint32_t *)0xDC00000C) = 0xFFFFFFFF;
To make that the new OS doesn't receive signals it doesn't need, and don't its the only thing that runs?
// This is also necessary (exercise for the reader: why ?)
*((uint32_t *)0xC000001C) &= ~((1 << 0) | (1 << 11));
I think you reset the LCD to some initial parameters (LCD controller enable and LCD power enable?), so that the new OS can initialize everything how it wants?
I think I should learn some ARM asm and everything that goes with it :D
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Jim: 1/2 mark, as mentioned on IRC ;)
For OSLauncher updates, see also http://ourl.ca/10384/280610 and below :)
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The message i get from trying to use a regular touchpad nSpire with CAS commands is a message bow that tells me to buy a CAS. The CAS for regular nspire might not actually be good and my lead to the downfall of the nspire for things like the ACT because CAS calculators are not allowed to be used on it and if an OS included CAS functions, they might disallow all nSpires for the test. Take one for high school TI-nspire users out there and buy a CAS if you want it's features.
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The message i get from trying to use a regular touchpad nSpire with CAS commands is a message bow that tells me to buy a CAS
Which is natural if the Nspire is running the non-CAS OS :)
The CAS for regular nspire might not actually be good and my lead to the downfall of the nspire for things like the ACT because CAS calculators are not allowed to be used on it and if an OS included CAS functions, they might disallow all nSpires for the test.
Simply put, this is a completely irrational fear ;)
Not least because the Nspire has a PTT mode much more efficient than of the 84+(SE).
People who live in the many countries possessing restrictions such as "CAS forbidden" in standardized tests - no matter how utterly disconnected from real-world usage, and therefore stupid, they are - may want to campaign against that kind of brain-damage, and the incompetents supposed to regulate standardized tests.
In France, where I live, CAS functionality is allowed, and the non-CAS Nspire, whose math functionality is roughly equivalent to that of the cheaper, more programmable and highly popular 83+(SE)/84+(SE), is hard to find in stores. People stick to the programmable and once popular TI-68k series... or buy the overpriced CAS Nspires and help the profit margin of TI and distributors.
Indeed, CAS Nspires are sold at higher price tags than the non-CAS Nspires, though the CAS models cost less to manufacture (no interchangeable keyboards), and their OS had lower development costs (they had to do the CAS version anyway; the non-CAS OS required extra development effort for replacing functions with stubs which tell people to buy a CAS, and also for building the slow, incomplete and buggy 84+ emulator. On the CX series, the keyboard is not interchangeable, but the unjustified extra price tag of the CAS OS remains.
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In France, where I live, CAS functionality is allowed, and the non-CAS Nspire, whose math functionality is roughly equivalent to that of the cheaper, more programmable and highly popular 83+(SE)/84+(SE), is hard to find in stores. People stick to the programmable and once popular TI-68k series... or buy the overpriced CAS Nspires and help the profit margin of TI and distributors.
You say the Nspire series is overpriced, but the 68k calcs have a smaller screen, no colour screen, less memory and are more expensive. Are the 68k really so much better programmable?
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Right, the TI-68k series are really expensive now if they're bought brand-new. TI lowered the price of Nspires, raised the price of TI-68k calcs, and distributors raised the prices to insane levels...
Are the 68k really so much better programmable?
Sure, there's really no doubt about that ;)
* BASIC programming is more advanced: it can output to the screen, it can read the keyboard, it can launch ASM programs and FlashApps.
* C/ASM programming is more advanced. People don't have to fight against a huge OS, which provides no support for programming. They don't have to spend time finding holes in them so that they can exercise their fundamental right to do whatever they want on the devices they own.
People can just use the official way to get access to 1500+ functions and variables, 1000+ of which are well documented, either officially (TIFS) or unofficially (GCC4TI). Instead of having to fight, they can (and do !) just build functionality - mostly games, but also native code math programs - on top of that foundation.
* there are various minority languages, such as a version of GFA-BASIC, NewProg (which predate Axe and Grammer for 83+-class calculators, BTW)... There is even an implementation of Lua, which never got the success it could have deserved. Needless to say, it's significantly more standard than TI's proprietary Lua for Nspires is - for instance, it can read and write files.
Seriously... four years and a half after its introduction, the Nspire series has unbelievably few programs ! ;)
At the end of the 1990s and the beginning of the 2000s, programmability was an integral part of the success of TI's calculators in the marketplace. Nowadays, TI listens to teachers and test regulations - making their machines less powerful, less versatile, and less desirable in the process.
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Seriously... four years and a half after its introduction, the Nspire series has unbelievably few programs ! ;)
At the end of the 1990s and the beginning of the 2000s, programmability was an integral part of the success of TI's calculators in the marketplace. Nowadays, TI listens to teachers and test regulations - making their machines less powerful, less versatile, and less desirable in the process.
TI doesn't need to make programming easy, teachers will tell their students to buy a calc anyway. At my school, most teachers like the V200 more than the Nspire, but despite that, they've been only buying Nspires for three years now.
Our teacher let us choose wether to buy a V200 or an Nspire, but because we didn't know much about calcs, everyone wanted the cheaper, newer Nspire with more memory and a "better" screen (non-cx). TI's website also implied that it had a color screen, but in reality only the student software has.
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TI doesn't need to make programming easy, teachers will tell their students to buy a calc anyway
Yep.
and a "better" screen (non-cx)
Indeed, the "better" is only on the higher resolution. The slowness of the screen was increased even further... The screens of TI-Z80 and TI-68k calcs aren't that good, and the screens of Clickpad and Touchpad Nspires are much worse.
Fortunately, TI fixed their wrong ways on the CX series.
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Damn slow screen on my TI-nspire Clickpad. There goes TI and releases 4 more nspire versions that make my model obslete.
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It's been a while since last I've been here and I know it's frowned upon in many forums to bring back something that's been dead like this but all I'm here for is an update. Has anything happened in the last few months? If not, I'm going to lock this thread next week.