Slashdot Mirror
Hewlett Packard's Cult Calculator Turns 30
Hugh Pickens writes "The Wall Street Journal reports that Hewlett Packard's HP-12C financial calculator has remained outwardly unchanged since its introduction in 1981. 'Once you learned it on the 12C, there was no need to change,' says David Carter, chief investment officer of New York wealth-management firm Lenox Advisors, who has owned his 12C for 22 years and still keeps it on his desk. 'It's not like the math was changing.' The 12C, which costs $70 on HP's website, is HP's best-selling calculator of all time, though the company won't reveal how many units it has sold over the years. The 12C still uses an unconventional mathematical notation called 'Reverse Polish Notation,' which eschews parentheses and equal signs in an effort to run long calculations more efficiently."
The 12C still uses an unconventional mathematical notation called 'Reverse Polish Notation,'
I still use the HP-41CV I bought new, made in Corvallis, Oregon ($400 or so at the time, with a card reader). Iâ(TM)ve never been able to do any significant math on a calculator that did not use RPN.
At least in the courses I took, most people preferred RPN.
If you want news from today, you have to come back tomorrow.
My first real calculator was the HP11c, although I got it in '84 or '85, not '81.
The CB App. What's your 20?
I still have an HP11c, you can write games on it and do some very clever maths using this machine. The 11c and 12c look very similar... RPN is exactly the same as machine, but with BCD.
The purpose of existence is to make money.
This is the scientific version of the same calculator, complete with RPN, a stack, plotting functions, matrix functions. I've had mine since 1991. It's a shame they tried to replace it with one that is crap.
Tamran
You would think given that calculators still sell pretty well and this one is doing good for 30 full years that HP would maybe consider that they made a mistake in essentially killing off this line. Wouldn't it be wonderful it HP put out hand device for engineers as far advanced a the HPs were then?
Anyway the scientific version of the 12c is the 15c: http://www.hpmuseum.org/hp15.htm
And my love was the 28S. http://www.hpmuseum.org/hp28c.htm
Now bring back one of the models the scientists/engineers will care about, like the 15C or 42S.
I own an HP-16C which can handle different number bases. I wish I had another one for work. I have an application on Linux that does the conversion but it isn't the same. Calculators still have utility even with almost unlimited CPU power at your fingertips.
I also own an HP-41C with a time module and it acts as my alarm clock as it has been for the past 30 years.
The older 12-C were well-made with excellent keys. The ones in the past six or so years are made in China, have poor keyboards that rattle when the calculator is lightly shaken and the keys will occasionally register a double press. Sorry, but I am keeping my 12-C (and 15-C) from the late 80's.
If you find one in the wild, and don't have a personal use for it, Ebay it. Those things are worth their weight in gold. Sold one for almost $200.
:-)
I still have my 28c and I have a nice 48sx under Android and Linux. I love this calculator and it takes me so long to figure out the non-RPN calculator.
Neil Cherry - Linux Smart Homes For Dummies
"It runs on an unconventional operating system called "Reverse Polish Notation," which eschews parentheses and equal signs in an effort to run long calculations more efficiently."
I didn't know RPN was an operating system. Perhaps that's what they mean by unconventional.
Although I never had a 12C, I did get a 48G back in '91 or '92. RPN is only unconventional if you haven't used it. After mastering it and the stack on the 48G, its simple to store countless values right there in memory and do lots of number crunching must faster than traditional calcs.
It's too bad HP seemed to destroy all value in their calculator lines shortly after the mid 90s or so. Luckily these things are tanks that will last a very long time.
My grandpa had an RPN calculator made by Novus. I don't remember which model but it came out in the mid-70s. I remember playing with it when I was a kid. CSB
Hedge fund managers are assholes and such calculators featuring on WSJ should be banned.
Realize that this is slashdot and mod this +5 Insighful. Thank you.
RPN is not a notation. It's a straightforward implementation of stack-based expression evaluation.
In RPN (restricted to binary operators) any sequence is valid where at each binop the number of preceding operands is greater than the number of operators.
R = v1 v2 binop1 v3 binop2 v4 binop3; ...
R = v1 v2 binop1 v3 v4 binop2 binop3;
R = v1 v2 v3 v4 binop1 binop2 binop3;
In linear notation, without parentheses, your ordering options are limited:
R = v1 binop1 v2 binop2 v3 binop3 v4;
Linear order implies structure from syntax. RPN implies structure from order. So does human language, in an effort to make communication more effective.
How many idioms in English have matched delimiters? None modulo common usage, n'est pas?
the reason rpn gives the shortest way to write expressions is that there is a natural 1-1 mapping between a stack and a tree. and since people try to organize most knowledge into trees (until they run into insolvable groups), the most compact way of representing trees will win as a method of representing most operations.
Any guest worker system is indistinguishable from indentured servitude.
The 12c is one of only two calculators admitted to the popular CFA certification exams, which might explain some of its more recent success. Still, there's nothing better to just crunch a few numbers on the go.
My HP 48G died after about 10 years. It just eats batteries now, lasting maybe 30 minutes on a set. I grew to love RPN before the 48G died, though.
My foot it is. All depends on what career you are in if its 'unconventional' or not.
Strange thing is these cost as much as they did when i bought mine 20 + years ago.. They should be cheaper now, so what is up with that?
---- Booth was a patriot ----
Look at any business school class these days any you will not find very many HP-12Cs or TI BA-IIPlus calculators anywhere. Most serious number crunching is done on a spreadsheet so the only use for one is if you are in a meeting or need to do a very quick calculation when a computer isn't readily available. (happens now and then) The HP-12C is a fine piece of equipment but if you have a spreadsheet available it's kind of like using a slide rule. Sure it works but it probably isn't the best tool available most of the time.
I'm actually a certified accountant. I have one of the TI BA-IIPlus calculators and the only time I have used it in the last 8 years was to take a certification exam. (they only allow those two calculators in the test) Otherwise it sits in a drawer and gathers dust. Frankly I can't imagine I'm going to use it in the next 8 years either. For reasons I cannot fully grasp a lot of accountants still insist on using paper tape calculators to add up long strings of numbers even though they have a spreadsheet available on their computer. I can't begin to count the number of times I've seen accountants repeatedly type in long strings of numbers because of typos. Strange people who aren't willing to change with the times. I'm waiting for one to ask for the "4:30 autogyro to Siam one of these days.
It may have been designed for financial calculations, but it holds its own for science and engineering tasks, too. A lot of problems in a lot of fields lend themselves very naturally to RPN workflows.
I learned to use these from my dad - he still has his, and I'm not sure there is any so-called feature that could ever make him give it up. Even when I was required to have a TI graphing calculator for classes, I found myself using it in RPN-style due to having learned to use the old HP (the last result is stored, allowing you to use the 'ans' key as a very short stack).
The 12C and friends are, in my opinion, nearly perfect as far as pure calculators go. They don't do anything your cell phone can't these days, but I've never met an app that felt as natural for handling pure computational tasks, and I have never needed to place a call from my calculator. Sometimes, purpose-built hardware is just better.
-V-
Who can decide a priori? Nobody.
-Sartre
HP made great calcs before the 12C. I had a 32E, my oldest brother had a 45, and my other brother had a 21. Now git before I break out one of my slide rules (straight or circular)
I am Slashdot. Are you Slashdot as well?
She gutted HP calculator R&D. The HP49G was the last new calculator they designed, I believe, and that was approximately 10 years ago. I still have my trusty, old HP48GX. I don't have a chance to use it much these days, but it is resting at a place of honor in my home office. HP made excellent calculators over the decades and it is a shame that a short-sighted CEO ended that legacy.
Solve the equation, using RPN:
2 x + 4 - = 3 x *
I don't even know if you can use the equal sign like this in RPN....or if you can even solve an equation with RPN. RPN is considered unconventional because 2 + x - 4 = 3x is more in line with what we want students to be able to solve. When they finally use some assembly to create a calculator, then they will appreciate RPN.
No single raindrop believes it is to blame for the flood.
HP had a lot of cool useful durable products back in the day. Now they are just a crapware commodity product pusher with NO innovation.
Off the top of my head..
LaserJet 4/5
Calculators
Riloe server management
Tons of electronic calibration and measurement tools (RF testers, volt meters, signature analyzers etc)
back in 1981 to 85 ( highschool) i used a 41 c
The first question was always " where is thew " = " button
i loved the thing . i still use a 11c and have a 11c on my suse desktop
"I don't pitch OpenSUSE Linux to my friends, i let Microsoft do it for me
My 41CV died a couple of years ago, and I packed in the hell box. Display bled out and was unreadable, and I didn;t bother to get it repaired.
And I have a bunch of modules for it, financials mostly. And the wand, card reader/writer, blank overlays by the pound, stacks of solution books. I worked for a dealer... I also had a 67, but traded it in for th 41CV. And I had use of a 97 in between, but I never got very good at using it.
But - using the 41CV for balancing my checkbook was a blast. Organize it correctly, and you hit ENTER and saw either a zero or your error(s). Made that chore actual fun, for a while.
What terrific devices.
deleting the extra space after periods so i can stay relevant, yeah.
confusion around expressions like 6/2(1+2)
the correct answer is 9
This deliberately ambiguous, convention-mixing expression is being posted all over the place by trolls, with the real assholes insisting that one interpretation or the other is "correct".
Now bring back one of the models the scientists/engineers will care about, like the 15C or 42S.
Actually, it makes more sense to do what they did - bring them back as smartphone apps.
I may be biased but I think it makes more sense to put the functionality of various traditional handheld calculators into a single app. Perpenso Calc for iPhone optionally supports RPN and offers scientific, statistics, business, hex and bill functionality. More importantly you have the option to use a modern worksheet format for the time value of money, cash flow, amortization, break even, and profit margin calculations; or use the traditional button based approach if you prefer.
Thankfully, those of us who use emacs just run M-x calc to get back to an RPN calculator which actually calculates numbers. (It's pretty much the main reason why my 48gx sits on my shelf waiting to be used.)
http://www.donarmstrong.com
Why do people cling to seriously outdated technology, that by today's standards is just a sorry joke of crappiness? Sure, back then it may have been awesome. But please, compare it to Qualculate! or even a full-blown suite like Mathematica on a small portable computer!
The problem is that like traditional handheld calculators, people do not always have their laptop/notebook with them. So applications like Perpenso Calc for iPhone are very useful because people will tend to always have their phone with them. With this single app you can make sure you always have the functionality of scientific, statistics, business and hex calculators with you.
This calculator is like a screwdriver: a perfect fit for the task.
The Platinum shipped with a bug. The 12C...well, there are no bugs.
RPN is great. Once you get used to it, you never look back. BTW, RPN is what the Forth programming language uses.
When doing financial calculations or shopping I always take it with me. Also to the bank. It creates an instant bonding between you and the manager (those initiated in HP 12C's RPN).
HP calculators, IIRC, were used to calculate the orbits in some early space program missions (YouTube). I think it's safe to say that the 12C is more numerically trustworthy than some Pentiums that came out....
Main difference between the BSD license and the GPL license: one is from California and the other is from Massachusetts
The "C" suffix stood for "continuous memory", meaning that programs and data did not disappear when the calculator was shut off. Like what every calculator does today. Before then, however ...
My first HP was the HP-25, a glorious invention when it came out in 1975. It had 49 programming steps, and the program had to be re-entered from the keyboard, line-by-line, every time the calculator was turned off. My first real programming success came when a high school math teacher, trying to show how hard it was to determine whether a given number was prime or composite, asked my class to determine whether the number 300,000,007 was prime or not. (Thirty-five years later, I have not forgotten that number, and don't think I ever will.)
I was able to program a test for primality into the HP-25. It was brute-force, of course -- checked for an integer result when the argument was divided by two, and then every odd number from three up to the square root of the argument -- but it worked, and I was able to show that 300,000,007 was prime. The teacher was impressed, both with the calculator and with the fact that such a large number that she picked out of the air at random turned out to be prime. (I don't think she new or cared about programming.)
I love that calculator. The HP-25C came out the following year, and the HP-25 became an orphan, but I still have it -- along with an HP-48G+ purchased about 12 years ago. (Finding a new calculator with RPN turned out to be harder than I thought.)
I always thought RPN was a ridiculously complicated way to evaluate expressions. Looking back after having seen the light, I don't see how I would have made it through two engineering degrees without it.
The 9 key on the HP 12-C, Platinum edition is not reliable after being pressed a few thousand times. This has been reported by many finance types, and makes the platinum unusable.
http://xkcd.com/645/
PLEASE bring back the HP-15C .... pocket size, scientific, RPN ... batteries last almost forever
while you are at it a modernized HP-200 sure would be nice - modern defined as easily readable LCD, battery life like the HP15C, and some type of removable storage - keep all of its existing features.
I own a 16C and wish I had another one to take to work.
I also own an HP-41C that is still my alarm clock. Programmable alarms, and the ability to run programs is so useful.
Calculators still have a place and utility even when you have unlimited CPU capability at your fingertips. Sometimes a purpose built tool can still beat a GUI.
I use my HP12C daily. Still impresses my clients. When I use a commodity calculator, I will have to check my work. The calculator on my Mac can be set to use RPN.
......and they were ANAL BEADS! Get of MY lawn.
Over-the-top Response Guy! Giving "Over-the-Top Responses" since 1970.
It is clear that the operation in parenthesis occurs first so 6/2(1+2) becomes 6/2(3) or 6/2x3. The question then is do you multiply or divide first. The precedence I learned in school was multiply, divide, add, subtract (mnemonic "My Dear Aunt Sally") so that would be 6/6 or 1.
I was always taught that multiplication and division were of equal precedence since they are equivalent operations algebraically. Dividing by 2 is the same as multiplying by half. Addition and subtraction also have equal precedence since adding -2 is the same as subtracting 2. I wasn't taught any mnemonic. (Mnemonics can be useful if correct but I'd call that one silly).
So if you want to be algebraically consistent, precedence isn't the real issue at all. The real issue is whether you calculate left to right or right to left for equivalent precedence. Do you do the division first (left to right) or multiplication first (right to left). Either makes sense algebraically but the usual convention is left to right, just like we write our sentences left to right.
This is indeed how most modern calculating systems work. Type
=6/2*(1+2)
into either Excel or Open Office calc and you get 9. (Use the original form =6/2(1+2) and both will offer to auto-correct to insert the multiplication symbol, since neither t support the shorthand of dropping the multiplication symbol)
But we do agree that the best thing to do is be unambiguous and add brackets everywhere.
Either 6/(2(1+2)) or (6/2)(1+2)
Even better though not as compact 6/(2*(1+2)) or (6/2)*(1+2)
These posts express my own personal views, not those of my employer
As long as calculus isn't involved, a spreadsheet is best. I did an Astronomy masters (finished 2002) and significantly cut down my time doing assignments involving simple algebra by using a spreadsheet. It was a distance course. We also had open book exams, and were permitted to use any calculation tools we wished. The only rule for assignments and exams was no collaboration.
Advantages of a spreadsheet: Repeatable. You can see your work and modify or correct mistakes at will. Graphs are limited but easy. Both statistical and scientific functions. Time saved can be used to do simple checking (plugging the answer back into the question).
Reverse polish is good on old style calculators for exactly 2 reasons:
1) You have the limited input and output of a calculator keyboard and screen.
2) You more closely mirror what a turing machine/computer is doing, so if you're trying to understand one it's a good way to get closer to the architecture
Reason 1 disappears if you spend most of your time sitting in front of a relatively modern computer.
Reason 2 has less to do with the calculation than it has to do with IT and computer science. And once you have a good understanding, you're just reinforcing that same knowledge.
Spreadsheets are excellent but have no native ability to solve or graph calculus equations. For that I would use a math package. Octave and SciLab can be had for free. Matlab, Maple, and Mathematica for more money if you're serious.
These posts express my own personal views, not those of my employer
I first learned RPN in the seventies on my first calculator, an HP 45. When it was stolen in the eighties, I got an HP 16c which I still have and which still works flawlessly. At work I mostly use RealCalc on Android with radix and rpn modes turned on, but I also keep a 48C in reach. I *can* operate a regular calculator, but RPN makes so much more sense to me.
My daughter took to RPN easily at 13 years old, but it confused her teachers so she had to go back to conventional notation.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
My first, last and still running HP calculator, the HP-11C. The thing is an amazing workhorse that has beat up, dropped, kicked and continues to work flawlessly.
I'm surprised that in this programmer rich environment no one is mentioning the HP-16C along with the 12C and 15C.
I bought my 16C when they first came on the market to replace a broken calculator I had used for doing Hex/Octal/Binary/Decimal conversions.
I had fun with it for a few years trying out some algorithms on it when I couldn't get my computer code to give the correct answers. I haven't done low level programming for a couple of decades now.. HP sent me a letter asking for any programs I wrote on it so they could build up an library of programs to promote interest in the model. I still have the functioning calculator which I use occasionally for my primary purchase decision, to convert bases.
We used to refer to the opcode/operand arrangement (RPN) generically as either prefix, infix, or postfix and we were very flexible with how code was structured in different architectures. Of course it's all stack and register based.
Terry
And there hasn't been a single mention of this internally. It's a sad husk of the former company these days...
I can't disagree with you much, but for my work, I may need to perform field calculations that require an immediate guesstimate. For that, I can use an 8 oz calculator which turns on instantly, or a 5 lb laptop that takes 2 minutes to get to a spreadsheet. . . .And my employer refuses to supply a laptop.
I like to double-check myself with spreadsheets, and for fun, wrote a vba rpn calculator. I also build some rather extensive statistical models with spreadsheets with a level of detail that would take a year with a calculator and paper records. I've also done finite element modelling both with a calculator and a spreadsheet. I can definitely see and understand the difference in the practical uses for both.
Recently, it occurred to me that Octave might be better for one of my models than a spreadsheet, but I've had trouble getting the time in to learn the software. *sigh* I've used both Matlab and Mathematica when I was in school, but it's so long ago, that my ossified brain refuses to instantly bring up needed experience.
Have any recommendations for a good online Octave tutorial?
Never had a HP calculator, but I typed in a RPN calculator program for the VIC-20 about 25 years ago.
Mostly random stuff.
I have a 15C that my sister bought for me in December of 1985 as a gift for college. It is my primary calculator - I've never found anything better. I don't program it as I used to, but it's still a damned fine piece of equipment. And in those years, I've changed the batteries 3 times, by the way.
Do you have ESP?
I use my 25+year old 15C at work (and inherited a spare). And it still has some polynomial calculator programmed into it from college days. My wife (a dog trainer) uses her 11C that I gave her in college (that was entertaining) to calculate dog agility course times - flummoxes anyone who asks her 'can I borrow your calculator'. And the calculator apps on my old palm and new droid are RPN. Can't do 'normal' calculators!
I still remember my first HP graphics calculator back in college... it was blue.
Given the crap spewed in your post, you ARE NOT a "certified accountant"
I was always taught that multiplication and division were of equal precedence since they are equivalent operations algebraically
Completely accurate. The full mnemonic, for the record, is "Please Excuse My Dear Aunt Sally", or "Parentheses Exponents Multiplication Division Addition Subtraction".
That being said, a number of people take the mnemonic a little too literally, believing it to mean that multiplication comes before division and addition before subtraction. In reality, both have the same priority, as they are equivalent operations, as you stated.
Quickest link I can find to explain it: http://www.purplemath.com/modules/orderops.htm
My sig can beat up your sig.
The author's blog written in very good, description is very in place, I love Abendkleider from deberry.
Given how much these things sell for on eBay and how many people say "I wish I still had my HP" or "I wish my HP still worked" or whatever, I am sure there would be a market for a remake of these classic HP calculators. Not some rip off with crappy cheap plastic running a half-baked emulator on a cheap ARM chip but a genuine remake of these things with the same attributes (battery life, reliability etc) that made these calculators so popular.
Hey, if Unicomp can make money selling copies of the old IBM Model M (not just rip-offs, they actually bought the Model M technology from Lexmark who inherited it from IBM), why cant HP (or someone buying the rights from HP) do it for these calculators?
Or have Texas Instruments calculators taken over so much of the market that there is no going back?
cult /klt/ Noun
1. A system of religious veneration and devotion directed toward a particular figure or object.
2. A relatively small group of people having religious beliefs or practices regarded by others as strange or sinister.
Hmm ... I fail to see how the term applies here.
I totally miss my HP non-programmable rpn engineering calculator. The answer was always correct. With technology being what it is today I can only imagine how difficult it would be to follow up on those old classic models. Let the engineering guys design it for utility.. and keep the business planners, marketing and arts department out.
Spreadsheets are good, but for simple problems they can be unwieldy compared to a calculator. For example calculating the square root of 8 is three keypresses on an RPN calculator. On Excel it's one mouse-click into a cell, followed by nine keypresses ('=sqrt(8)' + return).
Here's my hierarchy of tools for solving numerical problems (putting symbolic math aside):
I do support for the 12c for EMEA and it's crazy how obsessed people are with these things. The problem with such a long life span is we get irate customers when they have one for 15 years, it dies, they buy a new one and it only lasts 7. Like really really angry people. Any $70 piece of electronics that lasts 7 years you got your money out of, stop yelling at me about HP not caring about Quality Assurance on calculators. The other horrible thing about these is the buttons. We get people demanding replacements because the buttons are either too hard or too soft. "The buttons on my 12c that I bought in 1985 felt much different than the one I bought last week!" Really? The ones that have been worked in by 25 years of use were more malleable?
I haven't read this thread yet, but I'm sure that people have made the above two complaints.
Like many here, I prefer RPN to algebraic notation - a lot. When my 41CV got stolen (to whoever stole it - may your hands rot of!) I tried to find a good replacement. Unfortunately, by that time the more-or-less acceptable 32s(II) was replaced by the abysmal 33s. I got out my 32e (who remembers those? It was my first calculator back in high school) and being frustrated at having to charge it all the time (everything else is fine ...) I decided to write to HP. In a quite angry mood, I found a feedback form on the hp calculator webpage and let loose with my frustration (nor good rpn, layout unusable etc.). To my surprise, I received a personal reply (!) telling me that soon a new product would be introduced. I said to myself: ok, don't get all excited, just see what happens. Then, a few months later, the 35s became available. Not bad at all, although the shift buttons (blue/yellow) are in the wrong place and so are the operators (+ - * / ). But hey, just because the email I got it anyway, although my brother gave me a 12C platinum edition for my birthday...
It still works great, and I use it every day in my job.
I also have the m48 app for iPhone, which is a handy HP48 emulator that similarly works great when I'm out and about.
I bought my HP 42S back in 1989 and used it for 19 years straight, almost daily. In 2008 I realized that it was a bit scratched and that I should get a new one and make my old a spare (it worked flawless) in I lose the new one. Found a pristine one on eBay.
Now I figure I should get a third one, because if I can get two decades of service each, I need a third to last my life out. I'll never have to use anything else!
Does anyone use calculators for any serious maths these days? Outside of education everyone uses computers where there is any heavy calculation involved. Engineering is all CAD, accounting is all spreadsheets and financial packages, science is mostly processing experimental data. Maybe some theoretical physicists still do maths by hand but even then it tends to be a question of formulating and proving equations rather than using them to do individual calculations.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Calculators are special purpose devices, useful for special purpose applications. I can look at a screen full of horribly formatted data and if I'm adding 10 8-12 digit numbers, I can key them into a calculator faster than I can copy and paste them into a spreadsheet or a calculator program. For thousands of calculations, I'll write a program to parse the data, but for a handful of quick off the cuff calculations a device that has a lot of buttons is much faster and more useful than anything that involves a mouse.
I've been using HP 48's for about 15 years now, so I may be biased towards tools that just work. If eBay prices for old HP 48's are any indication, I'm not the only one who still sees them as useful.
I just got done tamping down the urge to spend unreasonable amounts of money on uber cool calculation hardware, initially inflamed by reading the Wikipedia article about the Curta mechanical calculator... and now this damn slashdot discussion about the calculators I fell madly in love with back in my callow youth (particularly the 41c)... sigh. Must stay away from ebay, must stay away from ebay....
My feelings about the HP calcs are pretty weird. The nearest analogy I can come up with is that the 41c is the beautiful girl you become infatuated with, and you know you can live happily forever after with if you can just get her... but you never do, so you settle and marry the girl (TI scientific calc) that "does the job".
Welcome to the Panopticon. Used to be a prison, now it's your home.
I understand how nostalgic it can be to play with older hardware, but I find that there is a disturbing undertone to the comment David Carter made when he said 'It's not like the math was changing.' The financial industry, while dominated by complex mathematical solutions to its problems, is not fundamentally a mathematical science, like arithmetic for example, where the math truly isn't changing. The fact of the matter is that this comment exemplifies how dated our financial industry is and that is in dire need of being changed. There are only a handful of industries that can use 22 year old machinery, and most of them are blue collar industries. Every other facet of our economy has evolved as a result to greater and greater technological advances to produce more real results, finance on the other hand uses dated practices that have been proven over time to be detrimental to the vast majority of practitioners.
My favorite unit, I even managed to beat Arthur Benjamin by double thumbing it in a Psych class one day.
http://blog.whybird.net/post/1036594686/arthur-benjamin-lightning-calculator-tywkiwdbi
I still have and love my HP-16C. For coding there was nothing like it. Makes somewhat less sense today, but it'd do 64-bit binary, octal, decimal and hex. If you look at the keys from the side though, you can tell that they painted over HP-12C or HP-14C keys and put different firmware in. I expect that the HP-16C is the rarest of the lot.
The 12C just keeps on using that wonderful notion of stacks. Makes life easy. Check out FORTH for those that want to do stacked computations and learn TIL work. Or Postscript as well.
I have a 10C sitting on my desk beside me right now. I also have a well-used HP-21 at home. I learned to use RPN back in 1975 and it quickly became second nature to me. Since then, I can't stand having to use a calculator with an "=" button.
I hope my 10C and 21 last for many more years, because I can't buy replacements any more. A few years ago I bought an HP-41, which was nice while it lasted, but as a newer model, it was made with inferior components and stopped working one day.
I really wish HP would reintroduce the HP-1x line, built like in the old days -- to be the BEST calculator you could buy, not the CHEAPEST.
The key advantage of the spreadsheet approach is the ability to go back and check that I've entered the right things after the fact is worth the extra key presses. You can correct a complex problem just by finding the error and fixing it without re-keying. I have to admit accuracy isn't my forte. I'm the kind of guy that would make one silly mistake in a complex calculation at school and bollox it up.
As for an Octave tutorial, I'm no expert here. Google is your friend, and I'll bet there's good information on the Octave site too. My Calculus is very very rusty. I managed to do an Astronomy masters where calculus was optional. It was geared to teaching at school and introductory college level. But I didn't do it with the aim of a career change. I did it because I wanted to know more about the subject.
Don't forget to check out other options. 3 that I've come across that were interesting to play with were Maxima (still current), Mupad (no longer offered I'm sad to learn as I type this) and Xplore (old one man project, no longer supported). I've used Xplore since the DOS days though and used it at uni so while I don't regularly fire it up I have a soft spot for it, and it was simple.
Here's the link for Maxima
http://maxima.sourceforge.net/
These posts express my own personal views, not those of my employer
Bring back the 16C!