Collecting Pocket Calculators

I collect old calculating machines for a hobby, anything, like shop counter adding, specialised scientific calculators, financial ones etc. Any old stuff like that if I go into a shop first thing check for the cabinet display if there's one I don't have.

Old Chess computers anything like that. Included is the very first versatile (primitive) programmable portable ones such as Casio, as with a simple Basic interpreter. My first computer programs were written on these models. 

They are a rare find these days, real museum classics, were very popular and affordable. These are actually real computers in real code and not the modern toy devices.

You had very serious machines even for industry like HP portable's and programmed in inverse polish notation, later on there was the HP also for Basic too.

Historical development

The first pocket calculator I saw had plus, minus, could multiply, divide and give square roots percentage and one number memory and gave eight digits. This has always been very standard. It had a (red) LED display and was very expensive. Texas Instruments.

The (black) LCD screens came only later. Ordinary penlight batteries replaced by the small wristwatch battery and often even little solar cells not needing replacing. Calculators use minute power. The models became smaller you even had a wristwatch calculator.

The interface on Sharp calculators are far superior the main competitors being Casio, the Sharp interface is much more logical and better organised than others. Later on some you had a larger screen and dot matrix. There is a fully formula-definition scientific a beautiful machine, as custom functions and a lot more memory. These one's not so common.

Calculators are faster now, easiest is to see is calculate 69! on the early ones it takes a second or two  must be with the machine actually doing the individual multiplications, 68 of them.

Hardware

Available memory space also steadily increased, at first you could store only one number, with time it became more and later on even own defined formulas stored, that could then be executed automatically. Sharp did very well with these kinds of defined custom functions.

There are models of course with specific applications, as for small businesses, scientific and engineering and financial and actuarial, more and more sophisticated analytic functions were added. All the later ones have extensive data analysing abilities, as all your usual standard probabilistic and statistics functions.

Pocket calculators thus became more and more sophisticated with time and able to do symbolic manipulations too and not just ordinary decimal numbers, other classes of data such as arithmetic with integer fractions or complex numbers, and come with advanced numerical techniques for calculus, solving algebraic equations and so on. 

Programmable, Hewlett-Packard etc

Fascinating, for me the calculators were very educational as far as mathematics goes and experimenting and figuring out all the different functions. Casio had very simple easy to use programmable calculators programmable in Basic as a success in actual practice.

One may learn writing little programs like testing for prime numbers, numerical methods such as finding roots of equations e.g. interval halving and Newton's method, for Calculus applications one may integrate functions and find areas numerically, methods such as Gauss Quadrature are easy to program, very useful things and simply writing formulas now also is no problem at all.

Of the first truly programmable calculators the HP49C inverse polish notation was very successful in actual industry and much more affordable too than your 71B.

The HP71B wasn't a success the interface was also very clumsy. It wrote in Basic. However now in my mind not a serious tool for industry, meant rather as a prototype but ended up little more than a curiosity and a status symbol among engineering students.

One could buy extra ram and a card reader (similar idea to a floppy writer) HP hardware is reliable and robust. Unfortunately the HP71B had a design flaw making it at times unstable. I donated mine to Wits when I left there the PC lab guys were starting an exhibition on the history of computers.

In a way it is unfortunate that few people I would think would ever need or could use all these calculating machines to their ability - if one thinks how it started off with as "to send a man to the moon!"

Other Tools

All kinds of other tools have been invented or discovered, there are more traditional specialised  calculating machines  if you know how to use them, such as logarithmic tables, and always for us fortunates I'm not bad with pencil & paper arithmetic. Not fast but accurate.

You can laugh but sometimes you could use your fingers, fencepost errors can be terribly misleading and secretly just a quick counting might avoid a serious mistake.

We were in the last class to have log books, logarithm and trigonometric tables aren't hard to learn to use you only need to understand the basics of exponentials. A slide rule in pristine condition would be a prize these days. So far I haven't learnt an abacus for counting but apparently it is very fast.

The past, and future ...   

In a way my own training and mathematical maturity has been parallel with those of electronic machines and mathematical methods, my mother's first employment was programming mainframes with punch cards and the huge data tape reels. Those were the very first computers she took me with to work sometimes.

They had air-conditioning it was great fun. My mother bragged with me everywhere we went. My dad too sometimes took me with to work to the air-force hangars he was a flight-sergeant and workshop manager. My dad grew up with valve amplifier radios phonographs and reel-to-reel tape machines after WW2, with the first transistor radios and sparkies experimenting on their bread-boards.

My dad was a firm believer in the electronics age he foresaw many of the wonderful things that we all now take so easily for granted, he believed in and enjoyed sci-fi stories, he would certainly have loved to see all the electronics we have here today.