[jacobolus]

They had different models with different capabilities. As they made minor style changes, they bumped the numbers slightly. The 81–82–83–84 were basically the same concept, as were the 85–86. The 89 and 92 were higher-end models. The 80 and 73 are simpler models intended for middle school.

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.

[Aeolun]

Huh. I have only good memories of this calculator. Would buy for my kids in a heartbeat. The fact that it barely changed is a feature to me. I know exactly what they’d be getting.

[wartijn_]

The scam doesn’t just work in the US. In The Netherlands most secondary school students had, and I think still have, to buy these. I imagine in other countries too.

There is an interesting side effect from having always used TI calculators. They use a dot as the decimal separator, not a comma like we do here. There is usually some option to switch, but the hardware button obviously stays the same, so I’ve always been taught to just make that switch in my head, and it has become the natural thing for me to do. I see 1,000.50 on a screen I write down 1.000,50. When I use software that uses a comma as the decimal separator, I get annoyed and it takes some mental effort to enter the right values.

[mrexroad]

> scam

… 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.

[jacobolus]

Plenty of students succeed just fine without owning a graphing calculator (they can spend a few minutes learning the handful of test-relevant features and borrow one for the exam). Thankfully as of this year there is also a Desmos option.

[Dwedit]

I think you can flash a TI83 Plus ROM to a TI73 by using an exploit? One exploit was that flashing an OS writes all the ROM, then checks the signature afterwards, then erases it if it fails. Pull batteries at the correct time and...