Vintage Calculators

[peter scott]

Ah, if we're getting into the big boys I also have an HP9100A with CRT display and core memory sufficient for 50 program steps and also a magnetic card for program storage. It was introduced in 1968.

Peter



http://www.hpmuseum.org/hp9100.htm

[Paul_RK]

I've been quite prone to them over the years. These few happened to be within easy reach, but the first two are the stars of the little collection, an Anita Mk8 from 1962 and a Casio fX-1 from ten years later. The Mk8 uses a multitude of cold-cathode tubes, ten ECC81s and a single transistor: I'm very glad I was on hand to rescue it for £1 at the local auction room somewhere around 1990. Disconcertingly that makes it about twice as old now as it was when I bought it... hmm. I think I need a glass of strong ale to reconcile me to that.

Paul

[Sony Bloke]

Glad I'm not the only one it seems to have multiple calculators.

Just had the calculator draw out, yes, apparently that's the thing

I have just found, in no apparent order-

Casio fx-7000G
Casio NS-3 Solar
Casio PW-70
Casio SL-807 Solar
Panasonic JE-362NU Solar
Sharp EL-506P Scientific (college calculator)
Systema LC-1500 (Broken, but very sentimental)
Systema LC-1500 MK2
Systema LC-1501 (just under my monitor being used as a clock)
Systema LC-1503

Probably loads more all over the house as well. 

[Mark Hennessy]

The FX7000G is my go-to calculator. I suppose it's vintage now - it was launched in the mid-'80s. We bought them at a discounted price through the school when we started our maths A level, and that calculator is still my "daily driver". It's a bit tatty now, but works perfectly. A few years back I picked up 2 mint examples second-hand, but sadly they both have display issues (both useable, but a shame nonetheless). One of them is a GA model, which is the same apart from a mild re-styling.

[peter scott]

Ah, if we're getting into the big boys I also have an HP9100A with CRT display and core memory sufficient for 50 program steps and also a magnetic card for program storage. It was introduced in 1968.

Peter

I've really been struggling to resurrect this machine. Unfortunately the service manual only covers the keyboard, power supply and display. All the other assemblies were serviced in the field by board swapping. With my very limited knowledge of what signals I should see I have been attacking it brainlessly by shot-gunning. Testing every one of about 350 transistors and many more diodes. I did find a faulty transistor in one of the many flip-flops and managed to get the arithmetic keys working but the trigonometrics and hyperbolics still resulted in a blanked display. The more I tried, the more it went wrong. I did come across a clock signal that wasn't getting to where it should. This was due to a faulty edge connector and what with the changing nature of the faults I concluded that all the motherboard edge connectors were suspect.

At first I thought that all the connections were not sitting proud of the plastic separators and tried carefully bending them slightly forward but to no avail. Looking at them under a microscope showed me that they weren't configured the way I thought and there was no way the separators were in front of the connectors.

   

I then tried washing the motherboard in the dishwasher but that made no difference to the faults. Deoxit contact cleaner was recommended to me but that made no difference either.



The edge connectors are mounted in a multilayer board that also includes a large amount of diode resistor logic and I don't fancy trying to desolder them.

I can see me admitting defeat with this thing.

Peter 

[Sony Bloke]

The FX7000G is my go-to calculator. I suppose it's vintage now - it was launched in the mid-'80s. We bought them at a discounted price through the school when we started our maths A level, and that calculator is still my "daily driver". It's a bit tatty now, but works perfectly. A few years back I picked up 2 mint examples second-hand, but sadly they both have display issues (both useable, but a shame nonetheless). One of them is a GA model, which is the same apart from a mild re-styling.

Yep, I remember buying the Sharp EL-506P calculator at radio and television servicing college, and it costing me an arm and leg, then a few years later buying the FX7000G and it being half the price. it certainly is a monster of a calculator.

Remarkably, they all still seem to work.

Ast.

[Sony Bloke]

Just realised, Ive got even more calculators Casio Calculator watches-

Casio CA-53W  (Back To The Future 1)
Casio CA-55  (Back To The Future 2)
Casio DBC-62
Casio DBX-100

Yay.  Think I collect too much stuff.

[Craig]

We're HP fans in our house. My first was an HP34C, which I alas give away. Silly me - they cost a small fortune now. I replaced it with an HP15C, which sits next to me and is my daily use calculator.

Also next to me is an HP50G graphing calculator. That is very close to a small computer, powerful, cryptic programming language. Got part way up the learning curve, but a bit like welding you have to use it daily because you quickly forget! I also have the printer that links to it via IR.

Also on the desk is an HP28S. That opens like a book with a dual keyboard. Same programming language as the 50G.

Upstairs I have an HP15C Limited Edition. That has exactly the same functionality and straightforward programming as the original HP15C, but has an ARM processor. It is massively faster than the original. And also an HP35S, which is a HP also-ran.

Many years ago I converted my accountant wife to reverse polish. So she has an HP12C on the upstairs desk and another one in her briefcase.

Back even further I started with a Sinclair Scientific back in the very early 70's, and then a Texas TI56 as an undergrad - but at that time HP's were unaffordable. The University library had HP calculators screwed to the desks (so they couldn't be pinched!).

Craig

[Craig]

The Sinclair Scientific had the typical Sinclair quirks. It had trig functions. But you could ask it to calculate (say) the arcsine of something greater than +/-1. Now that is perfectly OK - the answer is a complex number. But the Sinclair knew nothing of complex numbers, but it tried valiantly anyway. After a number of minutes with the display flashing fitfully, it returned an answer. A nonsensical answer of course.

The HP's handle it perfectly of course. For the arcsine of 1.5 the HP15C returns 1.571 - 0.962i to three figures. It also handles factorial of a non integer (technically a gamma function) so 3.65! returns 14.37. Matrix inversion - no problem, so solving linear equations is straightforward. Just love these calculators!

[ppppenguin]

Reverse polish is a great way to use a calculator. On a classic HP calc you do the calculation just like you'd do it by hand. Shame it didn't catch on. The only HP I have is an original HP35, bought at Harpenden many years ago for a pittance. Was working when I last tried it. Probably still working if I dig it out of whatever hole it's stored in.

These days I tend to use a spreadsheet if I'm at a computer.

ISTR the Sinclair Scientific could barely do sliderule accuracy on some calculations.