Then I learned that the US Bureau of Prisons had a rule against any calculator (or device) that was "programmable". So I programmed the TI-85 so its startup screen read, "TI-85 NON-PROGRAMMABLE CALCULATOR". Problem solved.
Me in math class in 1996 - I had a TI-82 things are programmable so I have no formal education, my parents are illiterate, and taught myself to program, and I begged them to buy me one.
I spent time learning how to code on it, writing from scratch, the game Spyhunter.
I couldn't figure out how to draw with lines or pixels so I used ASCII or text.
I presented this to my teacher who told me "these aren't for games". I was crushed.
Since I wasn't able to use computers or the Internet for that time, I did/read/learned a lot of things I wouldn't have otherwise learned. Learned how to make hooch (prison wine), how the law works and how to maneuver the court system (useful for both civil and criminal cases), got more fluent in French by speaking with some native French speakers from Benin, learned how to work out & lift weights (which I still do), and learned the value of freedom.
Legend.
The TI-92 had recently come out, and it had a QWERTY keyboard and could solve symbolic calculus problems like "find the derivative of 2x^3". This was a problem for the AP exam, since you could just type in the problem and get the answer. They fixed this by banning calculators with QWERTY keyboards. That's just about exactly when the TI-89 came out, which also did symbolic calculus but did not have a QWERTY keyboard, and so it was totally allowed on the exam. Boom, 5/5 exam score for Jorji.
TI-81 (1990)
TI-85 (1992)
TI-82 (1993)
TI-80 (1995)
TI-92 (1995)
TI-83 (1996)
TI-86 (1996)
TI-73 (1998)
TI-83 Plus (1999)
TI-89 (1998)
TI-92 Plus (1998)
TI-83 Plus Silver Edition (2001)
TI-84 Plus (2004)
TI-84 Plus Silver Edition (2004)
All of them are basically a multi-generational scam perpetrated against the hapless parents of American high school students who were told that they needed to buy overpriced anachronistic calculators for their kids to succeed in school. In my opinion the calculators have overall caused more pedagogical harm than benefit; the students would be better served by some combination of (a) problems that can be solved without the tedious but trivial numerical calculations these calculators support, or (b) are solved using a real programming language. If someone really wants to assign simple numerical problems, give the kids slide rules.
Calculators of this type used to make sense for an engineer doing work in the field somewhere, but make no sense in the context of a classroom.
… that continues no matter what. I gave my kid my 89 from the late 90s—I was happy to avoid the TI student tax. Then a year or two back, the college board banned the 89 from certain tests/classes and so I had to cough up for an 84. Even if you take care of your stuff, treat it well to pass on to your kids, the Man finds a way to extract their cut.
TI83 (1996) was a successor to the TI82 (1993) which was a refresh/update of the TI81 (1990).
TI85 (1992) was the second model they made, originally intended as a higher end version of the TI81.
Similar reasoning for the rest of their line up. Different models had different features, and then those models would get incremental updates/refreshes over the years.
I wasn't part of the team or anything, so if anyone has any insight to why exactly they called it that in the first place, I'd be interested to know, but generally speaking the answer is: When they released the first one in 1990, they didn't name it under the presumption that this family of devices would be a staple educational/academic electronics device for the next 3 decades with dozen(s?) of different iterations/generations over the years.
Joerg Warner has been collecting them exhaustively, and peering inside for date codes and such.
I would love to play something like that again on my phone.
https://en.wikipedia.org/wiki/Space_Trader_(Palm_OS)
I played it recently on iOS via the palm web emulator
Gonna be pedantic/crotchety about this because I got into advanced math classes but it was my brother who got the 84+ (I had to settle for a 83+). Guess who's the engineer now, and who's the NEET? Your kids pay attention to what (who) you value, folks.
Reason : making due with more scarcity increased independence and critical thinking.
I don't know if that was your point...
I had a TI-85 (maybe 86), unlike the entire rest of my school who had 83s.
There was a difference: when programming in TI-Basic, variable names on a TI-83 are limited to a single character. On the 85, you can make them longer.
But that was pretty much the only difference, and it will never come up if you're using the calculator for school-related reasons.
(For calculus, I had an 89. The differences are much more significant there.)
I also was the one person with a TI-85 in a school of 83s. But by the time I took the statistics class I knew enough BASIC to write my own programs to replicate the functionality that was missing.
No, I was too scared to ask.
Somewhat related. My mom once yelled at me for losing a necklace she really liked. Then we were moving her stuff out of her house and found the necklace behind a wardrobe, wedged between it and the wall. It had been there for like 40 years, layered in dust.
When Luther's house in Wittenberg was excavated about 20 years ago, a golden ring[2] was found that must have been deposited there before 1540. It is therefore quite likely that this is the ring mentioned by Luther in 1537.
[1] See WA, BR 8: no 3162 -- https://archive.org/details/werkebriefwechse08luthuoft/page/...
[2] Here is an image of the ring: https://www.zum.de/Faecher/G/BW/Landeskunde/rhein/geschichte...
My Catherine thanks you for the golden ring, whom I have hardly ever seen more indignant than when she realized that it had been stolen or lost through her own negligence (which is not likely for me, although I still insist on it), which I had persuaded her that this gift was a happy omen and augury sent to her, as if it were now certain that your Church would agree pleasantly with ours; this grieves the woman wonderfully.
edit: Not code, just convention.
The more practical reason to mount ground down is that wall warts with ground pins or polarized prongs nearly universally arrange them so that they're hanging down when inserted into a ground-down plug. If the plug's flipped, the wall wart's upside down and its weight is trying to lever it out of the wall.
TBH, in the house I mount them ground down, but under cabinets or in the garage/shop or etc I mount it ground up.
> 3x Processing Power - Matching one of the speculated options, the calculator appears to use an ARM Cortex CPU, finally retiring the z80 and ez80 family of CPUs that were used in three decades of TI-83 and TI-84 Plus graphing calculators. It's running at 156MHz, compared to the 48MHz of the older calculators. It appears likely that in an unexpected break from over 30 years of TI's operating system codebase, the OS has been re-implemented with new features natively on the ARM CPU rather than using an ez80 emulator to run an updated form of the TI-84 Plus CE operating system.
It looks like TI is finally moving away from the Z80. This must have been a pretty big engineering effort on TI's part. Like the article says, up to this point all of TI's low-end graphing calculators have been Z80 based and use the same system software that has a lineage dating back to the early 1990s. They were previously so wedded to the Z80 that when they introduced Python programming to their calculators, they did so by adding an ARM microcontroller that runs MicroPython, while the main eZ80 CPU acts as a serial terminal.
One thing that I remember vividly was you had no MUL or DIV, so you have to implement them yourself with shifts, adds, subtraction, etc. This was an extremely useful learning experience
Do you think you could remember most of Z80 ASM? I looked at some old ASM I wrote long ago, and it's hard to follow the logic of the program, since most lines are messing around with the registers. But basics like 'ld hl,xyz' and 'jp/jnz' still make sense.
I find when you learn things at 15 they tend to stick around. (Stuff I learned last week, not so much!) Even just looking at your example, I remembered that HL is a 16 bit register and you can split it into two 8 bit registers H and L if you want. I think most of it would come back; I wrote quite a lot of it, both for the TI-83 and later for a Z80 that I bought and put on a breadboard and wired up to some RAM and EEPROM, about as bare metal as it gets.
> most lines are messing around with the registers
Isn’t that just the nature of assembly? :)
>Kerm Martian
There's some names I haven't heard in a while :)
This is substantially inaccurate.
1) Not all ARM Cortex series CPUs have TrustZone. It is absent on many Cortex-M microcontrollers, for example.
2) TrustZone is an operating mode of the CPU, not an "admin processor". Depending on the part, it is often made accessible to developers. (Whether that includes third-party software developers is, of course, up to the device manufacturer.)
For more information, see:
https://developer.arm.com/documentation/100690/0200/ARM-Trus...
But yes. 99% of what we did with them in class - when we were even allowed to use them - could have been handled by a little solar-powered calculator with basic arithmetic functions.
I'm not one those (very admirable) people who build just to build, who make their own version of frogger or something. I need a problem to solve.
But making a program that would take the parameters of a physics problem and spit out all the other quantities or that formatted output the way my stats teacher wanted it was a huge timesaver and that motivated me.
I bounced off a python 2 tutorial and a C tutorial, but some random nobody's TI-BASIC tutorial that started really damn easy is how I became a Computer Scientist.
I eventually figured out python too!
I made my own game and got a little notoriety around the school for it.
Termux
pkg install python
python
print('hello')
ctrl+D
Acode
Termux + neovim
Termux + code-server (vscode-like, accessed through phone browser at localhost)
You're paying $100 for completely antiquated hardware where its core feature is "it doesn't do much".
Pretty much any professional environment that you will need calculations will have access to a computer that can do these calculations significantly faster and better.
I thought my HP was pretty cool in high school, but pretty much the moment I graduated I stopped using it because I figured out how to use Excel and/or a programming language to do number crunchy stuff. Even for CAS stuff, I would just use Wolfram Alpha or SageMath (depending on how ambitious I'm feeling with setting stuff up).
I can't remember the last time I used a calculator outside of showing someone else how to use it.
That unfortunately is also why they can charge so much and people buy them anyway, because at best you'll be on your own to learn how to use anything else (and at worst you won't be allowed to use it at all for tests and such).
Said friend was at a site and someone had misplaced the book. He pulled out a calculator and did some basic trig to give them the lengths and told them to get back to work. He said they were looking at him like he'd just conjured a demon or something. "You can... just calculate that?" "How did you think they made the book?" "But how'd you learn to do that?" "In that math class you dropped in high school."
But even still, the iPhone can do many things and is many times more capable, and you can buy a used iPhone 12 that works fine for about the same price as one of these calculators.
I distinctly remember my teachers having a debate around whether or not the functions I had programmed into my calculator were "cheating". On one hand, it was a tool and notes that I had access to my peers did not. On the other hand, I had created those tools myself, and if school was supposed to train me for the real world, wouldn't I be able to use the tools I created in the real world?
- was cheaper than a TI
- had a primitive CAS system
- teachers had no idea how to put it into test mode
It carried me through AP calc BC, I would’ve gotten <4 off of my own knowledge alone
One perk I found is that if I kept it in RPN mode, people stopped asking to borrow my calculator, which was a valid excuse to learn how to use RPN, which is basically all I use now (and indirectly made me really love the Forth language).
That thing was fine, and if I hadn't dropped it and broken it, I probably would have kept using it for the rest of high school. I eventually replaced it with an HP.
Neither teachers nor school districts have the time or resources to audit every new tool someone wants to use, or to help students figure out how to use their preferred tool to do something - find something that works and just use that
I had a cheap Casio fx calculator. It got me all the way through my exams in school and university. I had Mathematica at home.
While I can see that being very good on a TI-84 would help you complete exams faster and get better marks, is that a skill that we want students to learn? Being good on a fancy calculator is essentially useless in real life. In real life people use computers not fancy calculators.
IMO it's better to either allow only basic calculators, or to allow real mathematics software.
I wouldn’t have been able to function without it in school (20 years ago). But we also didn’t have iPhones.
I don't remember if you could connect an 82 to an 85, but I do remember you could connect it to a PC as well over serial
and this: https://web.archive.org/web/19990117001444/http://www.geocit...
I don't know. It's been too long. We must have done graphing on paper.
I don't remember a lot of coursework in math that required me to produce a decimal value. For example, we wanted √2 instead of 1.414.
In physics, I think we used regular calculators.
I used to be bewildered at my parents not remembering certain things from high school. But, now I'm living it :).
Now that I think about it, this could have been a strategy my high school drilled into us as a way to increase SAT scores, since TI-84s were allowed to be used there.
I suppose it depends if you took advanced math classes or not.
They actually started us on them in 7th or 8th grade.
I actually need a TI-82 in 7/8th grade, a TI-83 in high school, then college wanted a TI-89. I was having to upgrade every few years.
I know technology has moved on and all, but much nostalgic respect to these amazing calculators.
Probably have not touched mine since college.
There's even knockoffs of it for $1: https://www.aliexpress.us/item/3256809744184708.html
I picked one up when the 99 cent store was shutting down. It works fine.
Look what you can get for $20: https://www.casio.com/intl/scientific-calculators/product.FX...
TI is like the Intuit of the education world. I want to love them but this is ridiculous - a N4120 celeron laptop is the same price as this new calculator - it might be a garbage laptop but it's doing a heck of a lot more for your $160 than this calculator is.
Doesn't mean it's not overpriced, but that's one reason and you can get a used TI-83/84 for like $30 or less. They pretty much never break.
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1. Okay, the Casio can QR-code-link you to a graph, but if I have internet/smartphone there are better graphing tools anyway, like Desmos.
https://www.walmart.com/ip/Casio-FX-9750Glll-Graphing-Calcul...
The reason you can get used ti's for $30 is because that's how much they're actually worth.
You can get a catiga if you really want for like $17: https://www.aliexpress.us/item/3256809054964211.html
... or you can go with TI for $160 ...
It’s my favourite calculator and the one I always reach for, despite having a bunch of more complicated 2-line calculators etc. It’s just so easy to use and very fast to do anything I’d want with a calculator. If I need graphing I’ll reach for Desmos. If I need algebra I’ll use Sage. I haven’t used Sage since my undergrad, however.
[1] https://www.casio.com/content/dam/casio/product-info/locales...
[2] https://www.casio.com/ca-en/scientific-calculators/product.F...
Maybe everything is possible on the Casio, but it’s so much clearer on the NumWorks (especially for eg. Physics questions, where you might want to retrieve values you calculated earlier with full precision, etc). Genuinely felt like a cheat code when I was in highschool. I showed mine to my teacher and they swapped the whole’s schools standard calculators from the Ti-84 CE to the NumWorks, which is cheaper too.
I mean what do these do? I think like 10 digits worth?
If you're actually doing something requiring over 10 digits of accuracy and you can reliably hit that you probably have a $10 million lab...
So honestly what are we talking about here...If it's pure mathematics this is a bad tool for that as well.
In the exam, you'd also be at a disadvantage without advanced graphing.
https://www.amazon.com/Casio-fx-115ESPLS2-Advanced-Scientifi...
Includes GCD and LCM, some of the newer ones don't have them.
If you want graphing, there is the newish fx-CG100 has a nice display, but they removed Casio basic, it now only has micro Python (way too awkward to type on a tiny keypad):
https://www.amazon.com/Casio-ClassWiz%C2%AE-Calculator-Funct...
The older ones that still have basic:
https://www.amazon.com/Casio-fx-9750GIII-Graphing-Calculator...
BTW, here is a review I made of many calculators, measuring keyboard efficiency: (HP-15c still the best)
Four data points is sufficient to give you a 'good enough' shape and position of a second-degree polynomial. Five or six for a third-degree one. (And you barely see them, and don't learn how to algebraically solve for their roots in high school anyways, because the cubic factoring formula is a pig.)
If you can't tell what a function's plotted shape is going to be at a glance, you haven't learned the material to the degree expected of an attentive child.
Personally, I found great enjoyment in coming up with more and more involved plots in the Polar and Parametric modes, where yes I would predict what a graph would look like and then go over to see it. And then go back and iterate. Etc. Until I was painting pictures with functions and had a far greater understanding of the domain than I’d wager anyone who thinks graphing calculations are for finding roots of polynomials could imagine.
It is not nonsense. I'll draft an example.
Any second degree polynomial is a parabola that is either pointing up (positive a term), or down (negative a term). That term is an indication of how curved it is.
-b/2a is the X coordinate of the parabola's inflection point.
Plug that value into the equation and it'll give you the Y coordinate.
You now know the inflection point of the parabola, you know which way it points, and how steep it is, and exactly where the polynomial's roots should live (and whether or not it has any real ones!). If you remember what the squares of 0.5, 1, and 2 are, you can now connect the dots on a 'pretty good' plot.
This took yuo longer to read than it takes to do.
---
Similar transformations can be applied to sine waves, root functions, exponentials, logarithms, and reciprocals.
If you can't do this, or don't understand how to do this, you have not learned and understood the material. If all you've learnt is how to plug the formula into a magic $160 box to look at the pretty picture, and how to ask it to solve for roots, you and your teachers have wasted your time. The point of all this isn't looking at plots, the point is understanding how you can manipulate these equations, and what these manipulations do to them. This should all be drilled to the point of being intuitive.
Anything so complicated that basic algebraic manipulations won't get you the rough shape in seconds of work... Is more complicated than a high schooler is taught to solve.
I mean, these days kids have smartphones, what's the point of a graphing calculator?
Rant/Aside: Smartphones (or at least Android) are just generally really bad at being... smart, especially out of the box. No dictionary? No thesaurus? To say nothing of built-in encyclopedia (e.g. Wikipedia). Calculator worse than the $1 scientific ones? It's astounding how obvious it is that they're meant to dumb people down and just sell you crap when you look at the complete absence of basic functionality anyone from 50+ years ago might expect them to have.
Many tests will not allow you to use a smartphone. My son couldn't even use the school issued chromebook on his PSAT, he had to get a loaner Windows laptop or use an approved hard calculator.
However to answer your question: phone rules in classrooms vary enormously and the dedicated calculator is faster to interface when you're drilling problems in a homework setting
I finished highschool in the (gasp) 20th century so the modern classroom is certainly something I've had to learn
There isn't one.
The TI-83 is just a $160 tax on every high school student. There is precisely zero use in a graphing calculator before university.
If you ever need a plot of literally any function you'd be plotting in high school, you should be able to do a very quick, very rough approximation by hand. If you can't, you haven't learned the material.
* I used the programming functionality of the calculator to get around the rules
* I didn't care much for the math, but my TI calculator was my first programming experience and it's what got me to love programming
My experience is similar. We were allowed to use our TI-85s in class, but we had to go up to the teacher before the test and show him that we were running a factory reset, to prove we had nothing programmed in it to cheat.
My buddy and I had made a two player blackjack game and didn't want to have to retype it after every test. So instead we made a program that mimicked the factory reset process. You would run the program before walking up tot he front.
The only indication something was different was the three little dots in the corner indicating a programming was running, but we just covered that with our thumbs.
Ironically we never used it to cheat, only to not erase our game that we programmed!
One day, vexed by something, I vented my frustration by composing a profanity-laced rant into the Feedback window of the TI Connect app. (I don't recall the proximate cause, but I remember complaining that the product itself, which is still $110 today, is a total ripoff.)
I was certainly surprised when the (sole?) TI Connect developer responded by e-mail taking umbrage at my complaints.
0: https://education.ti.com/en/products/computer-software/ti-co...
I lost it at some point and got the version 2 and I would occasionally use it for work. I wish it had USB-C because who has a mini-B cable for charging these days
Originally that blocked the Ti-92, but then the Ti-89 and Nspire line had numeric keypads + CAS
When a calculator is used in a classroom, there's a concern about people using the calculator to replace the skill that's being taught. So, for instance, there's space for a calculator with no CAS, for a class that's trying to teach you to do algebra. That is in some ways easier than "don't use this function of the calculator".
Math problems should not require any calculator. Physics problems should require a scientific calculator. Overcomplicating the arithmetic shouldn't be the point.
Not that any of this matter anymore as it can be entirely replaced with LLMs in near future.
That screen resolution for one is horrible for 2026.
Also I don’t know about you but these days I welcome stuff that allows me to stay away from the damn phone.
I'm not sure such a device really improved any understanding of the underlying mathematics that I was taught. In fact, in more advanced mathematics these machines can't even keep up.
