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As far as I can tell the TI graphing calculators are riding entirely off of mind share/familiarity, both among students and teachers, and teaching materials, wh

As far as I can tell the TI graphing calculators are riding entirely off of mind share/familiarity, both among students and teachers, and teaching materials, which reinforces the former. Specifically textbooks and teacher training all use TI graphing calculators. Presumably tests are therefore made with the capabilities of a TI graphing calculator in mind. CollegeBoard actually has a wide range of calculators it allows for the SAT (https://collegereadiness.collegeboard.org/sat/taking-the-test/calculator-policy https://collegereadiness.collegeboard.org/sat/taking-the-tes...), but very few test takers take advantage of this. TI graphing calculators are based on sufficiently old hardware that it is probably faster to emulate a TI calculator on something with the power of a Raspberry Pi. Indeed an open source third party emulator already exists (https://github.com/CE-Programming/CEmu https://github.com/CE-Programming/CEmu). Does anyone know what the legality of selling a calculator that is a dedicated emulator of a TI graphing calculator (not just an online one like Desmos, but a purpose-made physical calculator that does nothing else)? I'm curious why this hasn't already been done before. EDIT: I mean a dedicated emulator that can do nothing else but be a graphing calculator, e.g. not something on a smartphone.

mdszy 7y ago
> I'm curious why this hasn't already been done before. Probably for exactly the reason you're asking about: legality. There's no way that the licenses of the TI calculator software allow for this.
- ghaff 7y ago
  IANAL but it's unclear to me why that would be illegal. See Lotus Dev. Corp. v. Borland Int'l, Inc. [ADDED: Basically said it was OK for Borland to sell a spreadsheet with the same look and feel as Lotus 1-2-3.] What probably is true is that the work-alike would likely not be certified to be used on exams unless some company spent the money to do so and then they're not really incentivized to sell the calculator for cheap. The whole situation seems very path dependent. There's probably no particularly good reason why you even need a graphing calculator. It's just sort of become the default.
  - mdszy 7y ago
    The parent comment isn't about "same look and feel", they're talking about literally dumping the ROM from the TI calculator and running it on other hardware. Could you sell a calculator, and say "hey this calculator has no software on it, but you can dump your TI ROM onto it and it'll run" kinda like how emulator software is handled on computers? Probably. Can you just straight up rip the ROM and start selling that on an emulated calculator? Almost certainly not.
    - dwohnitmok 7y ago
      Sort of. I'd imagine the hypothetical company would need to do a clean room reimplemention of the ROM rather than a straight rip since distribution of the ROM images is expressly forbidden in the TI license. That seems potentially hard, but not insurmountable, considering the relatively small size of the ROM. And then you get the rest through the emulator. Although it'd be interesting if the calculator had a one-time flashing capability that allowed you to load an emulator once and then make it immutable and there was a way for schools to inspect what was loaded.
      - saagarjha 7y ago
        Writing an emulator and then having your users dump their own ROM from their legally-purchased calculator is totally fine.
    - gowld 7y ago
      What do you need a TI ROM for? Programming a full-featured TI emulator on a modern OS is a college-level programming assignment.
umvi 7y ago
I mean, a quick google search shows that there are Ti-83 emulator apps on the market: https://play.google.com/store/apps/details?id=com.Revsoft.Wabbitemu&hl=en_US https://play.google.com/store/apps/details?id=com.Revsoft.Wa...
- dboreham 7y ago
  Schools often don't allow their use (see comments above).
- dwohnitmok 7y ago
  This isn't enough because it's not a dedicated emulator that can do nothing else. I would guess you need the inability for the hardware platform to do nothing else except be an emulator for schools to even begin to trust it.
  - pflats 7y ago
    iPads can use GraphNCalc83[1] and Apple Classroom on a teacher iPad/Mac to restrict students to the app[2]. I'm not sure if there's an android equivalent. I still find using a touch screen much more frustrating than a calculator with physical buttons, but this is a legit alternative. [1] https://acornaircraft.com/graphncalc83.html https://acornaircraft.com/graphncalc83.html [2] https://support.apple.com/guide/classroom/manage-app-usage-apd9c29dc86b/mac https://support.apple.com/guide/classroom/manage-app-usage-a...
- gowld 7y ago
  Fascinating, it seems to have been over a year since the last IP infringement sweep that removes these from the market.
dboreham 7y ago
I have two high school age sons. They attend the same school. I bought graphing calculators for both. One told me Casio was ok. The other said the school requires TI. Go figure.. Software emulations on smart phone are not permitted due to school rules about mobile device use in class. Also they aren't allowed for tests due to the potential for cheating. Of course you can cheat by storing extra info in a graphing calculator but they don't seem to have thought of that..
- dwohnitmok 7y ago
  This is what I meant by a dedicated emulator. That is the hardware is locked down to do absolutely nothing else except emulate a TI. The only reason to use an emulator is to save on dev work. A company providing this would still need to get it certified etc to get schools on board presumably.
- notjesse 7y ago
  I remember my math teacher used to come around and take everyone’s batteries out at the start of an exam to clear the RAM. Little did she know you can just save the notes in ROM that persists power cutoff.
  - StillBored 7y ago
    Well, I'm pretty sure the teachers don't actually understand 1/2 the functionality of most of these calculators even without the model variations. Even the non CAS models can solve a lot of programs numerically which in my mind creates a lot of confusion about what people gain with simple programs. Particularly as even without a built in root/etc finder, things like newton's method (or any numerical/recursive algo) can be used on the main calculation screen by using the previous result variable in equations and holding down the enter/repeat key until it converges or you get enough precision. Most of them also have a constants list that includes pretty much every constant your going to use in science/engineering/etc school. So I remember seeing some of my classmates programs for various classes and calculators (HP 84s/various other TIs), and I never remember wanting any of them because I knew how to solve the exact same problem with the built in functionality on my TI-85.
avgDev 7y ago
I ran an emulator on my phone but I was not allowed to use it during tests. I had to write complex programs on the TI to solve the math problems on tests(I wanted to be a programmer not a math wiz). I once had a teacher who made you show him that you deleted all the programs, well there was a program for that. :) I don't recommend using aides during tests.
CharlesColeman 7y ago
> TI graphing calculators are based on sufficiently old hardware that it is probably faster to emulate a TI calculator on something with the power of a Raspberry Pi. IIRC, most ran on Z80s except the 89 and 92 which used 68000s.
StillBored 7y ago
That list is a bit misleading because the vast majority of those calculators are no longer manufactured. So, you could pick one up on ebay/etc and use it, but the problem is that if it breaks or gets lost it may be difficult to source another one. Given that the user interfaces/functionality is different from model to model its not necessarily easy to go from a TI 85 to a TI 84. Which using that as an example, I still have my TI 85 my poor/single mother purchased in '92, but I ended up purchasing a TI 84 (ebay) for my middle school daughter this year because that is the calculator she knows how to use because they have them in school. Sure, I could have gotten one of the recent casio's, which is probably a better calculator than the '84, but its the same problem. The teacher shows them how to do stuff on the calculator, and the school's calculator's act as backup if she forgets/etc to bring it to class. That said, while they are a rip-off, I used the same TI 85 for 8+ years of schooling. Back then that calculator was banned by the college board AFAIK, for testing because it had linear algebra solvers/etc. (apparently its now allowed along with the 89, which makes no sense) Even so, while I was probably the most honest student in many of my college classes there were many times when that calculator had a built in function which would directly solve problems I found on exams. For a few years I had an ongoing joke that engineering school was just 4 years of learning how to use all the built in functionality of my calculator.
- sli 7y ago
  > That list is a bit misleading because the vast majority of those calculators are no longer manufactured. It does have the two most recent HP calculators listed, though. That's makes me pretty happy.
wtallis 7y ago
HP used to make their own custom CPUs for their calculators, with an architecture designed for BCD arithmetic using 56-bit and later 64-bit registers. In 2003 they switched their graphing calculators to ARM9 processors running an emulator of their old CPU architecture so that they didn't need to re-write the whole OS. SwissMicros did something similar for HP's non-graphing calculators, recreating the keyboard layouts but using modern ARM processors that run emulators of the original HP calculators. Apparently HP's early calculators did not include copyright notices for their OS: https://nonpareil.brouhaha.com/microcode_copyright_status/ https://nonpareil.brouhaha.com/microcode_copyright_status/
creato 7y ago
Regardless of hardware capabilities, I remember the TI-89 capable of solving some computer algebra problems that I couldn't get even Mathematica at the time to solve. TI calculators definitely do seem like dinosaurs in many ways, but the TI-89's CAS was seriously impressive even when disregarding the pitiful hardware it was running on.
- saagarjha 7y ago
  TI-89s use Derive: https://en.wikipedia.org/wiki/Derive_(computer_algebra_system) https://en.wikipedia.org/wiki/Derive_(computer_algebra_syste...

mdszy 7y ago

> I'm curious why this hasn't already been done before. Probably for exactly the reason you're asking about: legality. There's no way that the licenses of the TI calculator software allow for this.

ghaff 7y ago
IANAL but it's unclear to me why that would be illegal. See Lotus Dev. Corp. v. Borland Int'l, Inc. [ADDED: Basically said it was OK for Borland to sell a spreadsheet with the same look and feel as Lotus 1-2-3.] What probably is true is that the work-alike would likely not be certified to be used on exams unless some company spent the money to do so and then they're not really incentivized to sell the calculator for cheap. The whole situation seems very path dependent. There's probably no particularly good reason why you even need a graphing calculator. It's just sort of become the default.
- mdszy 7y ago
  The parent comment isn't about "same look and feel", they're talking about literally dumping the ROM from the TI calculator and running it on other hardware. Could you sell a calculator, and say "hey this calculator has no software on it, but you can dump your TI ROM onto it and it'll run" kinda like how emulator software is handled on computers? Probably. Can you just straight up rip the ROM and start selling that on an emulated calculator? Almost certainly not.
  - dwohnitmok 7y ago
    Sort of. I'd imagine the hypothetical company would need to do a clean room reimplemention of the ROM rather than a straight rip since distribution of the ROM images is expressly forbidden in the TI license. That seems potentially hard, but not insurmountable, considering the relatively small size of the ROM. And then you get the rest through the emulator. Although it'd be interesting if the calculator had a one-time flashing capability that allowed you to load an emulator once and then make it immutable and there was a way for schools to inspect what was loaded.
    - saagarjha 7y ago
      Writing an emulator and then having your users dump their own ROM from their legally-purchased calculator is totally fine.
  - gowld 7y ago
    What do you need a TI ROM for? Programming a full-featured TI emulator on a modern OS is a college-level programming assignment.

umvi 7y ago

I mean, a quick google search shows that there are Ti-83 emulator apps on the market: https://play.google.com/store/apps/details?id=com.Revsoft.Wabbitemu&hl=en_US https://play.google.com/store/apps/details?id=com.Revsoft.Wa...

dboreham 7y ago
Schools often don't allow their use (see comments above).
dwohnitmok 7y ago
This isn't enough because it's not a dedicated emulator that can do nothing else. I would guess you need the inability for the hardware platform to do nothing else except be an emulator for schools to even begin to trust it.
- pflats 7y ago
  iPads can use GraphNCalc83[1] and Apple Classroom on a teacher iPad/Mac to restrict students to the app[2]. I'm not sure if there's an android equivalent. I still find using a touch screen much more frustrating than a calculator with physical buttons, but this is a legit alternative. [1] https://acornaircraft.com/graphncalc83.html https://acornaircraft.com/graphncalc83.html [2] https://support.apple.com/guide/classroom/manage-app-usage-apd9c29dc86b/mac https://support.apple.com/guide/classroom/manage-app-usage-a...
gowld 7y ago
Fascinating, it seems to have been over a year since the last IP infringement sweep that removes these from the market.

dboreham 7y ago

I have two high school age sons. They attend the same school. I bought graphing calculators for both. One told me Casio was ok. The other said the school requires TI. Go figure.. Software emulations on smart phone are not permitted due to school rules about mobile device use in class. Also they aren't allowed for tests due to the potential for cheating. Of course you can cheat by storing extra info in a graphing calculator but they don't seem to have thought of that..

dwohnitmok 7y ago
This is what I meant by a dedicated emulator. That is the hardware is locked down to do absolutely nothing else except emulate a TI. The only reason to use an emulator is to save on dev work. A company providing this would still need to get it certified etc to get schools on board presumably.
notjesse 7y ago
I remember my math teacher used to come around and take everyone’s batteries out at the start of an exam to clear the RAM. Little did she know you can just save the notes in ROM that persists power cutoff.
- StillBored 7y ago
  Well, I'm pretty sure the teachers don't actually understand 1/2 the functionality of most of these calculators even without the model variations. Even the non CAS models can solve a lot of programs numerically which in my mind creates a lot of confusion about what people gain with simple programs. Particularly as even without a built in root/etc finder, things like newton's method (or any numerical/recursive algo) can be used on the main calculation screen by using the previous result variable in equations and holding down the enter/repeat key until it converges or you get enough precision. Most of them also have a constants list that includes pretty much every constant your going to use in science/engineering/etc school. So I remember seeing some of my classmates programs for various classes and calculators (HP 84s/various other TIs), and I never remember wanting any of them because I knew how to solve the exact same problem with the built in functionality on my TI-85.

avgDev 7y ago

I ran an emulator on my phone but I was not allowed to use it during tests. I had to write complex programs on the TI to solve the math problems on tests(I wanted to be a programmer not a math wiz). I once had a teacher who made you show him that you deleted all the programs, well there was a program for that. :) I don't recommend using aides during tests.

CharlesColeman 7y ago

> TI graphing calculators are based on sufficiently old hardware that it is probably faster to emulate a TI calculator on something with the power of a Raspberry Pi. IIRC, most ran on Z80s except the 89 and 92 which used 68000s.

StillBored 7y ago

That list is a bit misleading because the vast majority of those calculators are no longer manufactured. So, you could pick one up on ebay/etc and use it, but the problem is that if it breaks or gets lost it may be difficult to source another one. Given that the user interfaces/functionality is different from model to model its not necessarily easy to go from a TI 85 to a TI 84. Which using that as an example, I still have my TI 85 my poor/single mother purchased in '92, but I ended up purchasing a TI 84 (ebay) for my middle school daughter this year because that is the calculator she knows how to use because they have them in school. Sure, I could have gotten one of the recent casio's, which is probably a better calculator than the '84, but its the same problem. The teacher shows them how to do stuff on the calculator, and the school's calculator's act as backup if she forgets/etc to bring it to class. That said, while they are a rip-off, I used the same TI 85 for 8+ years of schooling. Back then that calculator was banned by the college board AFAIK, for testing because it had linear algebra solvers/etc. (apparently its now allowed along with the 89, which makes no sense) Even so, while I was probably the most honest student in many of my college classes there were many times when that calculator had a built in function which would directly solve problems I found on exams. For a few years I had an ongoing joke that engineering school was just 4 years of learning how to use all the built in functionality of my calculator.

sli 7y ago
> That list is a bit misleading because the vast majority of those calculators are no longer manufactured. It does have the two most recent HP calculators listed, though. That's makes me pretty happy.

wtallis 7y ago

HP used to make their own custom CPUs for their calculators, with an architecture designed for BCD arithmetic using 56-bit and later 64-bit registers. In 2003 they switched their graphing calculators to ARM9 processors running an emulator of their old CPU architecture so that they didn't need to re-write the whole OS. SwissMicros did something similar for HP's non-graphing calculators, recreating the keyboard layouts but using modern ARM processors that run emulators of the original HP calculators. Apparently HP's early calculators did not include copyright notices for their OS: https://nonpareil.brouhaha.com/microcode_copyright_status/ https://nonpareil.brouhaha.com/microcode_copyright_status/

creato 7y ago

Regardless of hardware capabilities, I remember the TI-89 capable of solving some computer algebra problems that I couldn't get even Mathematica at the time to solve. TI calculators definitely do seem like dinosaurs in many ways, but the TI-89's CAS was seriously impressive even when disregarding the pitiful hardware it was running on.

saagarjha 7y ago
TI-89s use Derive: https://en.wikipedia.org/wiki/Derive_(computer_algebra_system) https://en.wikipedia.org/wiki/Derive_(computer_algebra_syste...