Thursday, July 29, 2010

Interlude - Calculator history

This cartoon from last week really captured my view of "modern" calculators.

Click on the image to see the entire cartoon from XKCD, including the highly relevant punch line.

I was originally going to riff off of this cartoon to discuss "modern technology" in the classroom, but then Dean Dad's article came along. Just for perspective, the current model (TI-83 Plus) shows up priced between $89.99 (on sale at Staples for the new school year) and just under $100 (at Walmart and Amazon). For comparison, the CPI says $110 in 1996 will buy about $150 of normal goods today, but computer prices have been going down even as performance increases. For many decades.

Further, the cartoon is not exaggerating the connection to 1996. Today's TI-83 Plus is still running on a 6 MHz Zilog Z80 microprocessor, an 8-bit cpu that dates to the mid 1970s (as an upgrade to the legendary Intel 8080 chip). The Z80 was used in such memorable machines as the Kaypro II (running CP/M), the TRS-80, and the Sinclair and Timex notebook-sized computers. [The Kaypro, like the Osborne, was a "luggable" computer that would have to be sent in checked baggage today. I still remember using both of those.]

Not exactly MODERN technology, particularly when you consider the limitations of the 96x64 screen compared to, say, a (much smaller) iPhone. This has practical effects in that the calculator has great trouble graphing certain kinds of functions and the interface for "tracing" to a zero is really crude. More importantly, for whatever reason, I see no improvement in algebra skills associated with the month or more of time spent specifically on using this technology. Students do not use the graphs to check their answers, but that is a topic for my other postings on this topic.

Other observations:

The Plus indicates it has 512 kB of flash memory rather than 32 kB of RAM on the original model. The Silver Edition has a 15 MHz cpu and even more memory, but the added speed is one reason why you can clear its memory so much faster than on the Plus. AFAIK, the main difference is that you can clear uploaded programs on the 83 Plus but cannot clear the equivalent programs that are installed OEM on the Silver Edition. The main advantage for students is that you can connect any of these to a computer and download modestly sophisticated applications into Flash memory that are run with the Apps key.

Naive instructors believe that students have to laboriously type in crude crib sheets listing, say, trig identities or chemistry and physics formulas as fake programs. Many do this, but TI provides sophisticated, indexed crib cards - and similar tools are also available from others on the internets. Anyone who "limits" students to a note card of notes but allows a TI-83 without clearing it is laughably naive. Might as well let them bring in a notebook.


FrauTech said...

The TI-83+ was current about 10 years ago. I'm pretty sure high school students nowadays are buying the TI-85. Not sure on its specs and pricing.

Doctor Pion said...

The TI-85 is even older and doesn't have a market AFAIK. You must be thinking of the TI-84, although it doesn't add much capability given the price. It is just a faster Z80.

Those kids might be better off with an HP, but that is for another thread.

The only place where I think the TI is superior to the newest Scientific calculators (like the Casio, at 1/5 the price) is in how you feed it a matrix or a vector. There are better ways of getting a graph.

FrauTech said...

You could be right, I just know it's something else now and the 83+ was state of the art 10 years ago, or so it seemed. I was looking at what Casio offers and it does seem superior in many aspects that you can have a non-scientific with some of the nice function stacking features of a scientific. I was wondering what goes into schools recommending one brand over another. Do they get discounts or something? Very similar to the way Mac pushes into colleges.

Doctor Pion said...

Require, not recommend.

This isn't my territory so I don't know which came first, the book or the calculator, but I suspect it started when the TI-81 appeared. Once people started using the TI-81, they likely wrote or demanded books written to support what they were doing.

Today we have courses where the book goes hand in hand with the TI-83/TI-84 calculators, right down to screen shots and keystroke sequences.