Wasnt there some guy claiming to be a time traveller looking for these things?

We must be related then, because in 1977 I was almost the same age (14) and had a TI-59, my dad was a mathematician, and he had a matching TI-59 with the printer. Funny.

Which old HPs and TIs do you have?

TI-89 has been and will be my tool of choice for some time, unless I am at the computer and can use Mathematica or Maple. Both are such powerful tools and can reduce human computation by a huge margin.

Transport yourself back in time 33 years.

When I got my HP45 I sold my yellow aluminum slide rule for half what I paid for it 6 months prior, my friends thought I was crazy. (I still have the ivory one from the 40's.) The advantage to using these to study engineering was huge.

My adviser said if he could smuggle one back into his native Poland it would have been worth a car.

These were a much bigger deal than a pansy ass calculator that was marketed by TI giving them to high school math teachers.

I just remembered, my Dad had one of the earliest portable ("near pocket sized") calcs in around 72/73? I think it was made by Bowmar and was super spendy, like $300-400, but we're really pushing the memory recall now. I might actually have it here somewhere.

I got my HP 11C (scientific) and 16C (programming) back in the 80's some time. Still using them....
-Chris

They were called the "Bowmar Brains". I remember the ads in the mid-70s, when I was in high school. I think they did just basic arithmetic.

In 76 I had a pocket Rockwell. I discovered that if I typed in a number and hit the division key then the mutiplication key it gave the square root of that number. Pretty cool because that calc did not have that function! I nevr new if it was designed to do that our if it did it by happenstance?

Also remember spelling words with it as well...

or better yet, just using basic arithmatic, how do you calculate the square root of any number to 4 places? We had to learn it in 7th grade but with pocket calcs I have soon forgot. Does anyone remember? It wasn't through approximations either, the teacher showed us a series of instructions - mostly plug-n-chug but it worked like a deadass charm.

I do it in the car, while driving, and I don't have access to a calculator.

Hey, remember when we were kids, before they taught us decimals, and we got to throw away the remainder? Yeah, those were the days...

I have my 15C from college and still use it alot. Not much mention of the 15C. I guess it wasn't very popular.

Never one to waste anything, I saved my long division remainders from gradeschool. I wish I hadn't tossed them out when I got older. I bet I could have got some cash if I'd put them on eBay. ;)
-Chris

Yeah, I do it to figure out my gas mileage. The rest of the time, its reach for the calculator or do a approximation (I just divide num and denom by whatever works until they're reduced to a manageable fraction). If I knew, as a kid, that as an adults only use long division during the 2 minutes after leaving a gas station, I'd probably have been less studious.

I don't think that I am as high speed, low drag as you guys are, but every year on the Navy Fire Controlman advancement exams I keep re teaching my troops how to convert base 10 to binary, octal and hex. The new squids just aren't getting the same quality instruction I did. They changed the curriculum, and now they don't seem to retain any basic digital, AC or solid state theory.
We are allowed to use calculators, but it doesn't seem to help if they don't understand the why.

Micah

I believe that is the TI-83 that is often used in highschool, at least in this area. I understand how big a deal these old calculators were at the time. A TI-89 has a computer algebra system, unlike the other lower number TI's, which is why it is so powerful.

Red-beard: those remainders become important when doing modular arithmetic.

That wasn't the point. If you were using a slide rule to calculate lets say, the thickness of a beam to support a certain weight, the slide rule says, "10". You needed to know enough about the underlying concept (not just blindly typing numbers into a calculator looking at a printed formula) to realize by orders of magnitude, this meant 10 feet, not 10 inches.

Remember the issue with that Mars Orbiter because one engineering team (Lockheed I beleive) used English units while the NASA team used metric? The calculator/computer enables more blind reliance on the answer because you don't need to validate orders of magnitude as you did with the slide rule.

Square roots with basic arithmetic?

Here's how you do it with an Abacus. Doesn't get much more basic than that. Just a way to do the arithmetic without writing the numbers down

http://www.gis.net/~daveber/Abacus/SquareRoot.html

If you don't want to root through that link, here's a link with about 10-15 different methods

http://en.wikipedia.org/wiki/Methods_of_computing_square_roots

Wikipedia is an amazing resource.

I bought one of these around 1981. The Sharp PC-1211 - the first pocket computer. It was AWESOME. At the time, we didn't have PC's in engineering school - still using friggin' punch cards and Fortran!

http://www.vintagecalculators.com/html/sharp_pc1211_tandy_trs80_pc1.html

I just ran to the garage and grabbed my dad's old HP 12C. I have an HP 10B financial calculator that I used to take with me when new car shopping for quick calcultions to see where the dealer was trying to screw me... Now that I have a PDA with Excel, I don't use it so much.

Speaking of punch cards, does this bring back nightmares for anyone else?! :D

http://forums.pelicanparts.com/uploa...1148234819.gif