You Never Call Your Old Graphing Calculator Anymore
The TI-85 graphing calculator was something of an icon back in high school. Almost a status symbol, and not just for nerds. Or maybe that’s just the way I remember it. Our class had a stock of TI-82’s, but the -85 was much more desirable (black case instead of blue… that’s the only distinction I recall, and now as I research it it appears to be no less powerful). Perhaps it was just that 85 was higher than 82, evenly divisible by 5 (again, probably just me), and it was your own, not from the community bin. And you could keep programs on yours.
It had a simple, BASIC-like programming language that allowed for writing simple programs. I remember writing a few that would apply a certain principle to a set of numbers to make my homework easier, and if I recall correctly this was allowed by our teacher to encourage learning about programming. In my early programming life (e.g., [PCjr] days — we’re talking mid-late 80’s here) I was obsessed with programs that asked for a password, so I probably also wrote a program that would ask for a password and then, er, do something. A few years later my brothers (I think) clued me into a program called ZShell that could be loaded onto the calculator that would run assembly language-programmed games. The games were amusing, but I think at that point (1996?) I had progressed to writing password-requesting applications in Turbo Pascal 7. (Hah.)
I don’t have any memory of the TI calculator after I started at Tech. It was either not that useful, or (more likely) programmable calculators weren’t allowed in tests (too much information could be crammed into ‘programs’ — treat them like text files, and you can hold a decent number of theorems). Plus, entry was much more efficient with my TI-36X (remarkable site, by the way). Nowadays if I need a calculator I use the built-in Mac/Windows calculators. Or use Google to convert units.
A few weeks ago we were at our local Tons of Stuff for Cheap store and ran across a TI calculator display. I was astonished at the prices: $130 for a TI-86! Now, I’m sure they’ve made a few improvements to these things in that time, but wasn’t that about how much they were going for 10+ years ago? Maybe $80. Maybe $100. For $130 you’d expect a color LCD! There doesn’t appear to be a backlight (for midnight integration?). The processor (Zilog Z80) and speed (6MHz) are even the same! There’s 96K of user-accessible memory now, up from 28K. Oooooh.
Perhaps $130 is what the market will bear, and so they set their price there. Although, $100 in 1990 money is equivalent to $150 in 2005 dollars, according to this inflation calculator. And while I suppose $20 is a nice price break, you’d think these things would be a bit cheaper nowadays (Moore’s Law, anyone?). Or maybe this is just another stage in getting old[er]. I look at the successors of things I once bought and marvel at how expensive they are nowadays.
August 22nd, 2006 at 10:40 am
Out of curiosity, do you have an equivalent for OS X that graphs and such? My old TI-85 is still around and still sees some abuse — I love the scrolling screen that allows you to see your entry history. I never did like that damn backwards HP input method and the main restriction on the ‘85 is that it feels so bulky, so heavy, so huge.
I never did find the rumored app for ZShell that produced music through the data jack to headphones.
August 22nd, 2006 at 10:56 am
There is Graphing Calculator, from Pacific Tech. At $100 it seems a bit steep, however.
Two of my coworkers (Chap among them) swear by the RPN method. I can see the appeal, but it never caught on for me.
As for sound on the data jack — I had no idea this was even possible, but here’s a program that claims to do it!
August 22nd, 2006 at 4:04 pm
I went through a couple TI-68 calculators during my 10 years in and out of Georgia Tech. As the datamath.org site says:
“The TI-68 lets you enter an expression into the entry line the same way as you would write it. You can move throught the entry line to review or edit any part of the expression before evaluating it.”
I routinely sneer[ed] at the guys spending three digits for their HP calculators, or even you guys with graphing TIs. For 99% of the work my $60 TI-68 was faster, including at basic programming. For the 1% of graphing and fancier programming, use your PC at home and quit dicking around with your calculator during lecture, young man! Oh and spare me the tears when you lose it :)
August 22nd, 2006 at 4:21 pm
Ah — but can the TI-68 play techno out its data-link jack? ;)
In retrospect it seems silly for high school kids to be using graphing calculators. Or maybe anybody, for that matter. My recollection of the parts of class that utilized them was that they were very tedious, with the teacher guiding us through it at the lowest common denominator speed. “Ok, now press 2nd. Yes… 2nd. Ok… everybody got that?” Perhaps it’s an effective way of letting kids see an “Oooh! Neato!” aspect of the Math, that an expression like y=x^2 yields a nice curve, but aside from visualizing curves, why is this necessary? If only some math teachers read this blog, all could be explained!
Also, datamath.org says the introductory price for the TI-85 was $130 in 1992 — about the same as today’s going rate for TI-86’s.
August 23rd, 2006 at 10:46 am
Man, I used the graphing functions on my 85 to get around some of the trickier problems. Technically, it wasn’t cheating, but I found it offered some rather “creative” means to an end.
I think TI donated the calculators to the schools in the same way it was a “requirement” in CS1501 that all students learn the basics of Microsoft Office on donated software — which, oddly, gets MS more points in the “we donate money” headlines. More people went out to buy TI-85s after using them in class so they could use the bricks at home and TI was happy to pull in the cash. I still love my ‘85 and, for awhile, carried it with me and used it in some USF classes. I got really weird looks for that.
RPN was impressive and made sense, but I never took the time to learn it and never invested in an HP. Do their calculators even recognize RPN input these days?