Abacus or fingers, mechanical or electronic, nixies, paper, LCDs or LEDs, how do you add up? A poem was part of the invite, the poem is included at the end of this post.
Over 20 people showed up despite the not so interesting temperature … rain rain rain and rain. At least someone showed up early enough to warm up the place.
Yves VK2AUJ’s Display
Flight Computer
This is a bit cheating, it is not a calculator but a computer, a flight computer. These were introduced in early 1900s as an evolution from the ones used by sailor, but needed to be more portable. Devices that could compute were called computers, way before electronic computers were introduced. Note that this device is still used nowadays by people learning flying navigation. This particular one was purchased in 1984.
HP41C (1980)
You were either an HP (Hewlett Packard) or TI (Texas Instrument) person at school. TI people would never understand the logic of reverse polish notation, but would lose any calculator contest. The HP41C was the crème de la crème in 1980, helped me in my engineering degree at university. They were very expensive as base model, and prices of the peripherals and memory modules were out of reach. Still works today but uses 4 x N batteries which are not sold everywhere and are quite expensive for their little capacity. In opening the case, I found a cheat sheet I wrote at the time, it is written on a punched cards that I was still using at the time for some programming.
A “handy” way to multiply by 9
Using your hands to multiply by 9 is a fun things to show kids. Lets say you want to multiply 4 by 9, fold away your 4th finger and read the answer from left to right, the number of fingers before the folded finger reads the tenths, and the units from the remaining fingers.
And now, 8×9:
Brian VK2AXC’s Display
Burroughs Calculators! Brian who worked for Burroughs’ in the 70s. Before calculators, they had the Comptometer, designed in the 1920s, which Burroughs redesigned.
Listed features: Portable, doesn’t required power, dual registers, and more.
Sean VK2THT’s Display
High school collection: in 1970, we either had to purchase a slide rule or we couldn’t do the subject. When you finished your study, you put it back in a box and waited 50 years before taking it out to bring to the 5th Wednesday. Sean was more interested in electronics than doing homework so he got into the Electronics Australia magazine. Sean’s first calculator was a 4 function Sinclair. The TI65 was the next best long term calculator, which got trashed when the NiCad eventually died. Casio soon became the norm, put fresh batteries last night and still working. The best next things in your pockets were the mobile phones, Nokia were quite handy at it.
Geoff VK2TGO’s display
Very accurate slide rules were required when studying at uni. Once study was completed, upgraded to an HP.
Richard VK2ARH’s Display
Richard was a month too early for his display and got ready with some verse: here is his slide-rule poem. The slide rule belong to his dad, the Ode to Arthur.
The Slide Rule – An ODE to Arthur VK7GH (SK)
I saw him study late at night, books piled up all around
Graph paper, pens and pencils were also to be found
But my eye was always drawn to the fancy white machine
Mastered with skill and precision, no electronics to be seen
“”
Be it formula or equation, or problem to be resolved
An answer from the slide rule, had every challenge solved
It was a symbol of mathematical and engineering skill
It bestowed upon the owner, a mystique that remains here still
“”
To be an engineer he studied electrical at that
But the secrets of this white machine he kept under his hat
It wasn’t till later schooling that the secrets were passed on
But the slide rule’s awe and kudos, no longer brightly shone
“”
For electronic marvels had taken, the slide rule’s prestige place
Although simple by today’s machines, they lead the race to space
But I always will remember my father’s slide rule skill
And the love he had for numbers and problems solved at will
“”
My love of radio and electronics will never be undone
For it came from a man who shared, his passion with his son
But his memory’s kept alive by a simple white machine
Which by my side, when in my ‘shack’, is always to be seen.
“”
The slide rule may be dated and no longer hold its place
As APU’s advance, at an ever-increasing pace
But with those who hold the memory of an era long gone by
We salute the slide rule warriors, looking upward to the sky
Richard VK2ARH
Carmel VK2CAR’s display
1950s British Bell Punch Abbreviated Comptometer (Adding Machine) – note the portability
Allows fast addition operations. Operators use both hands simultaneously, using the keys in parallel, and operate without looking at keys as one would by touch typing. Allows for fast addition in accounting, faster than electronic calculators that came out in the 70s.
Later machines could do subtraction via the ‘method of complements’ where nine’s complement keys featured smaller minus numbers next to main integer on each key. A button to activate subtraction was added; and later devices can also do multiplication and division.
Back story to acquisition…
Was staying with my husband in Leura and we visited a big old antique/junk shop on a corner on the main street of Katoomba. I saw the adding machine at the foot of the door and went to find the owner sitting at a messy desk behind some hi-fi junk.
“Wow, how much for the adding machine at the entrance?”
The grumpy curmudgeon behind the desk said, “Not for sale.”
“How come?” I asked.
“It’s a bluddy door stop,” he barked, “There’s another in Aisle C.”
I asked, “That’s C for Comptometer?”
The grumpy guy grumbled something and we went and had a look. Mostly old cassette decks and computers. We found the adding machine but on close inspection it had a big ding in the back.
I moaned and Steve said, “Go wander around, I need to find the boys room.”
I wandered to the main desk and Steven returned and stood behind me, holding the addng machine.
“How much? “I asked.
“$50 bux,” he said.
“But it has a big ding in the back!”
“Yeah. Ah. Okay okay, forty bux.”
I slapped two twenties down and we left.
When I got in the car, Steve dropped the machine on my lap. It was the one from the door! He had swapped them out!
Been many years. I think we got away with it, hi.
And it’s been a fun adding companion all these years, good for my accounting, but mostly used as a handy door stop 🙂
Glenn’s Display
Similar story about slide-rules, only told allowed at school, no electronic calculators. Got a Texas Instruments TI-59, top of the range in 1980 … but forgot to remove the battery for long storage with disastrous consequences, unlike Sean how took the time to remove the batteries.
TI-59 Home Page https://www.ti59.com/ and TI-59 / TI-58 – Wikipedia https://share.google/fylAuwZNLJWnNvAIm
Fully electric mechanical NCR calculator, still operational, was still able to find suitable carbon brushes to fix the motor.
Tim VK2TIJ’s Display
Display of a paper base circular calculator supplied with equipment and booklet to assist builder doing some calculations.
RIchard VK2NRA’s Display
Mal VK2TMF’s Display
Apple II clone refurbishing project. Visicalc was the first spreadsheet in 1979 and running this evening on the Apple II.
Richard VK2NRA mentioned that in the early 1980s there were many unused PCs in the NAVY where Visicalc was running and suggested that they should be used to run the finances, which they started to do. Richard became the Visicalc “instructor” for the area.
The Results are In…
And the winner was… MWRS with 69 “gold coin” votes overall!
In the popular vote: 1st place went to Brian VK2AXC with the Burroughs calculator, and 2nd was Glenn with the electrical calculator.
On the story, Richard Hinsley VK2ARH with the Poem!
Message from Clifford VK2CLF:
Sorry that I won’t be there to offer you the opportunity to vote for my 1974 “Sheen” pocket calculator. Red LED display, RPN, and 9.5 digits internal precision. I figured out how to calculate twelfth roots to 14 decimal places using this classic, so I knew it intimately. Perhaps the only non-HP calculator the used RPN, it still works perfectly on a 9v battery.
But sadly this evening was scheduled at the same time as my holiday.
Ode to the Calculator
On July the 30th, Wednesday bright,
MWRS hosts a nerdy delight!
From Casio clicks to TI beeps,
Celebrate math that never sleeps.Slide rules, Sharp minds, HP flair,
Logarithms floating in the air!
Sin, cos, tan — functions divine,
Crunch those numbers, it’s your time to shine!Vintage or new, bring your display,
Key in the fun the calculator way!
Add, subtract — multiply cheer,
Divide the boredom, bring good gear!So punch those keys, no need to stall,
At MWRS — it’s fun for all!
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