1920 Comptometer Mechanical Calculator

The 100 year old Comptometer can't be that cool can it? Nope, it' even cooler!
The first 500 people who click the link in the description will get 2 free months of Skillshare Premium: skl.sh/akbkuku3
I really, really, like this thing. It seems like I'm always saying this, but I didn't expect this thing's capabilities to be so deep. I liked the Burroughs Portable, but the Comptometer is so much better it makes that look like a toy. I really had to cut down the things I wanted to say about the Comptometer for this video to keep it a reasonable length. I could go on and on about it because despite it really only doing one thing, it is shockingly capable. I defintiely think a Comptometer belongs in everyone's vintage calculator or computer collection.
Comptometer Manual: archive.org/details/methods1921
Burroughs Portable Video: • Burroughs Portable Add...
Playlists of more stuff like this:
Calculators: • Calculators
Other Links
KZbin: / akbkuku
Github: github.com/AkBKukU
Thingiverse: www.thingiverse.com/AkBKukU
Patreon: / akbkuku
Discord: / discord

[@retroguy74]

I understood all of the words, but somehow still don't know what was going on. I'm glad at least one of us understands this thing.

[@PaulinesPastimes]

I remember being in awe of Comptometer operators in my early working life. They did something secret and magical. I am afraid you lost me after "This is a Comptometer" haha. You are a genius. Cheers.

[@robertlozyniak3661]

Secret and magical? It sounds like you never got to play with one of them. Here you go: www.jaapsch.net/mechcalc/compsim.htm Go ahead, play with it! It's not real, so you don't have to worry about breaking anything, or messing up anyone's work. Come on, you know you want to.

[@PaulinesPastimes]

Strangely, I think I do. I will review the video and see if I can master dividing 22 by 7, just for fun. Maybe I will start with 2 + 2 :-)

[@devvynully]

It would have blown my mind if the advertisement was a skillshare course on using compometers.

[@rhandeymaahrsch2151]

So many unanswered questions... Are the keys genuine Cherry blue or just rubber domes? Does it need to be online for product activation? Does it come with antivirus and automatic app updates? Is it Bluetooth compatible? Is it iOS or Android compatible? How long does it take to boot it? Power consumption? Can you expand the memory? Does it work with SD cards over 32GB? Does it support standard IOT protocols? Fan noise? Overclocking potential? Reviewers these days are so superficial. Sigh.

[@LoneBraixen]

They use lever switches Yes, you'll need to have an account with Comptometer, and you'll have to sign in with binary It is not Bluetooth compatible, but it uses a much older standard called Blacktooth It is Android compatible, but only for the HTC -1 (thousand) The software is in ROM, booting for the first time should be instant. Updates are stored in separately sold floppy disks, or tape if you're broke It's a 0.002 watt system Memory is only expandable with 8" 80 kilobyte floppy disks This does not support IOT, that's stupid I don't think many people are fans of this device now, so I'd say fan noise is pretty low Overclocking is totally possible, just attach electrodes to your hands and it will run faster. Be sure to have adequate cooling though

[@rileycoyote4924]

Ok Boomer

[@TinyMaths]

You know, it has been said, that after a certain baseline, having too much choice is a predictor of lower levels of happiness. I know that's a bit simplistic, but I wonder, I wonder if gadget freaks back then were a bit happier than today's gadget freaks?

[@MrJavaman5]

I just want to know if I’ll be able to play Doom on it?

[@tarstarkusz]

My dad took all his engineering classes in the 50s and early 60s. All on slide rule.

[@bubbadmatt8124]

My head hurts

[@MrJozza65]

When I first started work 38 years ago, we had 2 comptometer operators in the office who could do calculations faster than I could work an electronic calculator. In my job (Quantity Surveying), the task of adding up all the accounts was called "Comping" too. I tried to learn how to use one, but only ever got as far as adding up.

[@robertlozyniak3661]

Multiplication can be done as repeated addition. If you want to multiply 89 by 7, then put your fingers so as to add 89, and just mash the buttons 7 times.

[@stephenhewett929]

When I started work 43 years ago we had two ladies dedicated to operating comping machines for electrical building services estimates, we still used typewriters and the only calculators were the Texas LED type, I don't think people understand how much technology has advanced in such a short time.

[@MCGeorgeMallory]

Love the blue bar for the sponsored part of the video. Just like a loading bar, it’s an excellent device for helping improve patience!

[@scuzzamiga5004]

In 1972 I worked for a precast concrete company in an estimating department. During the day quotes would be put together manually and then when complete placed in pigeon holes. I would then collect an armful and take them to the ground floor. On the ground floor was a very large room filled with ladies all in tidy little lines at single desks carrying out the calculations in the estimates using types of these machines. They were then returned to the main office and signed off by the senior estimator and director. We had two calculators and two telephones in an office of twenty plus estimators. The drawing office of forty staff had three telephones and used slide rules. Nobody had a calculator or trusted them. The job of 'Comptometer' was not just a machine it was a skilled job and the sight of dozens and dozens of ladies all punching in the numbers and pulling down the lever was quite mesmorising. ... and there wasn't a computer to be found anywhere. The job of calculating was that of these ladies and so getting things right could mean whether a high rise block of flats fell down or not. In the sixties one did.

[@jefbed212]

The three handed method is probably the fastest :D. I admire the mechanical skill required to invent and construct those machines as well as the clever methods for achieving mathematical operations, whereas I was under the prior impression that adding machines can only add.

[@Cardthulhu]

Hey! I have one of these. Fully functional Model J. Found it in a Goodwill for 8 dollars. Serial Number puts it at a 1926 production date. And it was painted Olive Green, which means that sometime in the mid-50s someone sent it back to the factory for refurbishment. Every model refurbished in the 50s got repainted at the factory to the new standard color of the recently released electric machines.

[@kaitlyn__L]

The speed of the comptometer vs the calculator reminds me of the speed of trained accountants using abacuses, pushing multiple beads at once being similar to pressing the multiple keys at once to move entire numbers around.

[@martijn208]

that was interesting, yet i din't understand one thing you explained there.

[@mikemcgrumpy]

Oh thank god. I thought I was the only one :-)

[@katho8472]

Yep, quite too fast.

[@myMotoring]

that's why the operators were taking a dedicated class to use it

[@pmarquisYT]

It's quite easy to understand, it's all about the registers and the gears.

[@LoneBraixen]

I really like this video format, everything is very nicely laid out, and you explained the device very well. I wish more creators would label how long a sponsor spot is like you do, there's nothing worse than getting uninterested in an ad quickly simply because the host just goes on and on about the sponsor with zero indication of how long the spot is. I always enjoy your videos. They are formatted in a way that makes a lot of sense and they are crammed full of information in an easy to follow way. Even the way you handle sponsorships is simply brilliant!

[@romero-kyun2681]

What a smooth flex, showing us how to use a 100 year old calculator

[@jabbaa6500]

I used a comptometer in the 1970's. I would take home a machine and inventory from a company who was contracted to calculate the inventory for major stores in New York, J. C. Penney's, Sears and etc. Earned lots of extra $ at home at the dining room table. The machines are easy and accurate. Oh how I miss those days.

[@MetalPopka]

I already like this channel. This guy shows how long till the sponsored ad is done.

[@morgansinclair6318]

I love these old mechanical machines. Really gorgeous pieces of machinery both in operation and design.

[@Chriva]

Quite incredible how much we advanced back then. From mechanical to a completely new technology. We've pretty much only polished existing tech the last fifty years.

[@Chriva]

@@doodlebug1820 It's still nothing more than clever programming running on refined versions of what we've had for the last 50-60 years. The hardware is faster, has an order of magnitude more storage and takes way less power for a given workload but the truth is, this tech won't scale for much longer. We've almost reached the limit of what can be done with it. It's time to invent something new

[@freakinbox]

"I'm just here to have some fun" long after I went crosseyed trying to grasp what you are even doing LOL

[@bf0189]

You have such the coolest hardware! I'm really glad and thankful that you document all this stuff it's important. Technology historians in the future are going to be really grateful for your videos ! They are that good. When my financial situation stablizes I will become a patreon!

[@devnull128]

I just bought one of these, amazing tech for the time. Now I know how to use it a little. THANKS for the video!

[@robertlozyniak3661]

Another advantage of this over an electronic calculator: this has no "auto shut-off" feature. Let's say that you are buying items from a catalog (as in the old days) or the Internet (as we do nowadays) and are taking your time about making purchasing decisions. If you use an electronic calculator to keep a running total of your purchases, it will shut off on you, and you will lose the number. (I learned that the hard way.) For this purpose, it is better to use a mechanical calculator, which will wait patiently for you to input the next number, and will not lose your total. Just make sure that your mechanical calculator is cleaned and oiled and in good working condition, so that it will do the arithmetic correctly.

[@logickedmazimoon6001]

Use a smargphone calculator

[@TheDiner50]

Wow. Imagen carrying around a mechanical calculator just to add up a total. But to be honest I get quite angry when old people do math in there head I barely can begin to manage on a calculator XD This people pisses me off! And I mean the really good people that barely know how to use a modern calculator that do multi step calcs in there head like it is obvious and easy. But yea with modern phones with even a half decent calculator app can do so much. And on a personal computer Speedcrunch or just a good dedicated math calculator when sitting down at a table are to good to compare with a mechanical calc. And pen and paper go a long way to make up for bad math skills.

[@brianfuller7691]

I have one of these which passed to me from my grandmother. And it still works.

[@jeffw1267]

I'm lucky enough to have a 12-column version of this machine. If you have one it is important to oil it properly. I use sewing machine oil and it has to be applied through the key slots as well as the oil holes. If it's oiled properly it will never need repair.

[@BokBarber]

This video inspired me to get my own Comptometer which also turned out to be a Model H. After a little bit of practice, it's surprisingly usable for the basic 4 functions. Even division really isn't that bad once you know the rules. I won't say it's better than a regular 4 function digital calculator, but it's certainly more interesting than once of those and perfectly usable, especially for tallying up totals. It's also a marvel when you open up the case. It's amazing what they were able to accomplish with just gears, springs and stamped steel.

[@GrumpyTim]

Great video, don't you just love it when the digits roll over - that never gets old!!! The complementary subtraction is great fun. Funnily enough I was restoring one of these yesterday (well technically I was restoring a model F rather than a model H, so no first key press bell etc). I've just subscribed to your channel too. :-)

[@djangoarcher]

I saw this video 3 days ago. Now, I own a model J. It's so neat! Thank you, TT!

[@ZiggyTheHamster]

Overflowing my Burroughs Calculator is also my favorite part, though I've never thought to do it with the case off.

[@jeank1d]

Hey Shelby, just want to say you're looking very nice nowadays! Not sure what it is however it's really nice to see you so happy and composed in your videos!

[@5egrub]

So many clever tricks. Loved the 12x12 example.

[@evensgrey]

I wonder if the person who came up with the 'Totalizator' version name knew what a Totalizator actually is. (It's an obsolete class of mechanical calculators used for the special purpose of computing the payouts in Peri-mutual betting. This needs to be done fast, between when the betting window closes and the race is actually tun, usually only 2 minutes. There was a US company that made them, and they were one of the main investors in the Eckert-Mauchly Computer Corporation, the makers of the UNIVAC machines, the second commercially produced business computer line. The rather flamboyant CEO of the totalizator company could see that computers were the way forward for his business too, and invested heavily. Then he died in a plane crash and the board of the company didn't get it and demanded their money back.)

[@fl0atpvnk]

Cool antique device, but I got hella confused with that very detailed but very complex usage instruction 😟 I’d like to see the internals of this beast.

[@Many_Sparrows]

I understood everything you said. Great video, really enjoyed it!

[@ugyuu]

This is the most complicated way to explain how a calculator works or how to use it that I've seen yet. Fun!

[@jaapsch2]

Nice video. I feel the same way about the Comptometer. I only properly started my calculator collection and website after I got one. The Comptometer seemed to be somewhat dismissed amongst collectors for being too basic, and I hoped my site would redress the balance a little bit, especially through making available scanned versions of all the documents and manuals I could find. The manual you used is one from my collection.

[@mellowman247]

I graduated high school in 1972. In my sophomore year I studied advanced business machines. If you divided million by one on one of these calculating machines it would click 1,000,000 probably burning the machine up. Something I always tried to get away with on a Friday when the teacher was locking up the classroom but she always caught me. The following year a student brought one of the first electronic handheld calculators to school. I divided million by one and the screen went away for about five seconds and came back with the answer. In that moment I realized everything I had learned was now obsolete.

[@DevilishDesign]

Excellent video and great explanation of how these machines work. I've seen other Comptometers where the columns only go up to 5. Obviously a cheaper to produce machine and requires the double entry for each number as you described.

[@jharuni]

Beautiful machine and fascinating explanation, thank you!

[@TorSmedbergGames]

I like the relatively new graphics you have when showing pictures

[@philippberndt]

I saw it, understood 1/64th of how a comprometer works, damn. Great video, thanks for the great content

[@TrashfordKent]

Neat, very neat. Also i was a little confused by 9's compliment initially but looked it up online, maths is not my strong suit but i found this really interesting, thank you.

[@edwardreedy]

My grandma went to comptometer school at the insistence of her father. He believed his daughters should have some useful post school education. It landed her a job before the war. She then bucked rivets on B29's for WWII.

[@happybluecat7175]

Repeating and shifting to the right with the ones compliment number for long division is really neat.

[@amzrigh]

I have a comptometer! It's a different model than yours -- the digits aren't differently colored, and there's two fewer of them -- based on the serial number, I'm guessing mine's a model J? Yours is also in much nicer condition, mine's missing a few keycaps, and has some mismatched replacements on others. It was my grandmother's -- she was a calculator girl in the engineering department at General Dynamics (now Lockheed Martin). She said they used to hold races on them, and she usually came out on top. I never knew what those little levers above the register were for, nor did I ever notice that the keytops alternated shape by row! Very cool to learn more about this thing that's been around my whole life. :D

[@JamesPotts]

I want to see a video on that HP 16500b/c on the shelf.

[@MakotoIchinose]

Comptometer pioneers math speedruns, if that's how they intended to capitalise their calculator...

[@Ice_Solid]

This video made me feel like I don't understand math.

[@thereallantesh]

I generally consider myself a fairly intelligent individual, but after a long day at work this video fried my brain, lol.

[@lawrencedoliveiro9104]

You’re right, that is an amazing gadget. 10/10 would watch again. ;)

[@danielson9579]

What lovely noises it makes 🙂

[@FruitMuff1n]

I don't have enough room for this stuff in my house! So tempting!

[@maenova417]

Nice! It's awesome seeing how ingenious technology used to be :)

[@Damaniel3]

And time for today's episode of 'Mechanical Calculating Devices with AkBkukU'. I'd love to own one of these some day. I have absolutely no use for it but I really love old school mechanical devices like this.

[@maxpowers2168]

LOL the background flying graphics remind Me to the "Saved By The Bell" intro (ahhh Kelly Kapowski)

[@daviddavidsonn3578]

watch out they want to make a remake of the show... You really don't want to watch it though

[@MarquisDeSang]

Real programmers program with cogs and gears.

[@airborne2876]

If you wanna program an entire video game using only clockwork mechanisms, be my guest. Imma stick to C#

[@rxythmark666]

Space Faux Cog# alright alright I'll leave

[@radioflowers]

that is the best add segway ive ever seen

[@cheater00]

Hey Akbkuku, what a great vid. What did you say your other favourite calculator was? Sovox? Couldn't make that out.

[@KJohansson]

They are a cool piece of engineering!

[@dasy2k1]

I've used one or at least something very similar Unfortunately it wasn't fully in base 10! First few registers in base 10 then 1 in base 20 (0-19)then 1 in base 12 (0-11) and the last one in base 4 (labelled - ,1/4,1/2, 3/4)

[@SyphistPrime]

I want to actually use one. It would be cool to see one in a museum you could interact with and instructions on how to use it.

[@kellypaws]

My mother ran an office accounts comptometer department. We had a Felt & Tarrant comp' on the desk for years.

[@metallicarchaea1820]

That is a sweet hat!

[@mikemcgrumpy]

You get a thumbs up just for having spent the time learning all that.

[@twistidclowns]

I wonder how long it took to make one of these complicated machines

[@evensgrey]

Not a whole lit, really. What's surprising is that it wasn't in production 20-30 years earlier, as the technology needed to mass produce it (specifically, the ability for machines to automatically make precision, interchangeable parts) was developed by the 1850's (initially for military firearms, but the most common item most people would have been able to get as a result that they wouldn't have had before was a clock, the cartridge guns that also came from it are in incremental improvement over earlier guns). While he didn't open it up to explore the mechanism, this device is obviously highly modular and each module would probably have been assembled by machine, too, at least in later years. In a sense, this is a quintessential example of an industrial era product: Useful for a whole lot of applications, but takes skill to get the most out of it, and cheap to produce in quantity. The main reason we don't use things like this any more is bulk arithmetic is all done on computers now, and the computers gather all the numbers they need to work on as well.

[@ABaumstumpf]

Mechanical calculation of sums with such a large keyboard of course is easier to be fast - you are limited by how fast you can enter the numbers. And addition (and even simple multiplications ) depend on your input the most. I mean examples like "1+2" show this quite clearly - for basically anybody it would take far too long to enter this in any sort of calculator to be worth it - you know the result. "15+17" is a bit slower, but still just pressing those 5 keys on a calculator in sequence takes longer than doing it in your head. But here the Comptometer starts to shine - when you are trained with it you will basically just have to press something 2 times as you press the whole number at once. Accounting any many other tasks often involve just simply adding up many numbers - when you can easily enter 2 or more numbers per second, trained can be significantly faster. of course with modern calculators there are also people that can enter 20+ digits a second too, but takes longer to get to that point. But nowadays this has become mostly obsolete cause there is little reason to print and re-enter the numbers. You use a computer. If you have a long list of numbers to sum up you likely already have it in a table-form and opened with a table-manipulation software. And if not already setup to do the calculations beforehand doing so still requires little time. Adding up tens or thousands o numbers takes virtually the same time. And for getting data from the real world - USB callipers are a thing. No matter how fast you are: using them for data acquisition is faster than writing down the numbers or directly adding stuff up as the whole number can be taken with the press of a single button.

[@kevingordon669]

Got damn Im way too drunk to watch this, ya'll have fun

[@user-74652]

I'm honestly finding myself wanting one of these, even though I seriously don't need one.

[@bernhardwall6876]

You have some awesome machines. Have you ever considered having it "restored" to its original condition, like I see on some KZbin channels?

[@alexandernilsson5583]

When is the next video on the 70s data general mini computer?

[@ianmelzer]

I have a terrible condition (/s) where in the moment someone begins to explain math my mind goes hazy. Getting to second year calculus was a struggle, when a recording of someone explaining rudimentary algebra is an effective sleep aid for me. Cool machines though. Seriously the number of times I fell asleep in my Physics w/ Calculus class; why do they make the class rooms so warm?.

[@drfrancintosh]

I received a model B for Christmas and I'm excited to play with it. But the handle on my clearing mechanism is bent. I'm afraid to bend it back for fear of snapping. I wonder if you have any suggestions on how to fix it - or how to find a replacement handle.

[@jakublulek3261]

Such an impressive machine! I really only lived through the tail end of mechanical calculator era, and I continued to use slide rule simply because I cannot afford scientific calculator. But I never seen something this impressive, maybe they were hidden from regular students but even science department only had desk adding machines and some small mechanical calculators that printed on a paper tape. There were computers, of course, but not readily available, only in the science lab, connected to equipment. At least they were IBM 5150s.

[@hitorishinda5118]

Imagine not having Siri to help you do math

[@daphneblake7889]

I've got one of these! Except it has 12 rows of keys...it still sits on my old oak desk. It gets uses every now and then. Even for balancing my checkbook.

[@frankbonheure7064]

i have one, sadly the protective case is gone, rusted in a damp sellar. Still working thou and in nice condition.

[@Bata.andrei]

Can you do a division by 0? What does it do when you try that? Is that a HP 16500C? I own the B version and I love it to bits :)

[@MisterRorschach90]

Ever since I searched KZbin for calculators using mechanical switches like a mechanical keyboard I’ve been getting suggested your mechanical calculator videos. I still have yet to see someone make a calculator using mechanical switches.

[@robertlozyniak3661]

Try an HP-12C or something like that.

[@infi84]

I wish we'd have seen more of the insides :3

[@RetroRelixRestorer]

Great tutorial, completely understood everything you said 👍 🤔

[@dialupdave6276]

yes, I understand when you said the thing... about the stuff

[@richfiles]

I have a fully functioning Burroghs Comptometer clone similar in case styling to the one at 6:08. I also have six functional Nixie Display/Decade Counter circuit boards from a Bell Punch/Sumlock ANITA Mk7, like at 4:58. Sadly, I don't have the complete machine, but I want to someday construct a six digit electronic Comptometer using the six boards and six rotary telephone dials.

[@gregoryberrycone]

cypher, returning to zero... im getting metal gear solid 4 flashbacks

[@Boemel]

I have a 1918 model. no idea how it worked :D thanks.

[@johnsmith-yj2cn]

I imagine a kid trying to cheat math exam whit that

[@SameAsAnyOtherStranger]

I would love to get an overview on how the mechanisms work together. These old machines are virtual treasure troves of patents that have become public domain due to patents being time limited. The technology involved in the mechanical engineering of these devices isn't as antiquated as it may seem when you consider the relatively new and growing fields of robotics and mechatronics.

[@Saturn2888]

I was hoping for you to do a teardown of the internals like you usually do. First, this thing obviously isn't broken like everything else you have, but also, I was really hoping to see how it was actually laid out inside.

[@oldschoolcompsci]

me too

[@nickwallette6201]

I will have to study these operations. It seems they might be useful for doing arithmetic with logic circuits. I’m really curious about the square root operation.

[@robertlozyniak3661]

I just made a video about how to extract a square root using a Comptometer. I am not sure whether my method is period-authentic, but I believe that it easily *could* have been used in the old days. I wonder: in the old days, were the Comptometer operators encouraged to be resourceful in devising methods to perform calculations on their machines? Or were they simply instructed not to worry their pretty little heads about such things, and to instead simply (and blindly) follow whatever methods they were taught? From what I have read, I suspect the latter to have been more likely.

[@Modenut]

1337 indeed

[@GospodinJean]

Straight outta Comptometer

[@stoojinator]

This is cool, but I am so grateful of a proper calculator. This thing seems so incredibly tedious.

[@walktroughman1952]

I wonder if this thing could do powers in some weird fashion

[@dylanstandingalone]

I dunno why I have such an urge to call it the Compto.. Meeeeter! Instead of "Comptometer".

[@oscope61]

now i have to dig mine out of the closet and start playing with it again

[@nightisright1873]

Adding machines where the pong consoles of the 1880s

[@Fiilis1]

I don't know why I am even watching this.

[@bwhog]

You should watch someone taking inventory with a 10 key adding machine on their hip. I can believe that someone good a ten key can be just as fast as someone using one of these and possibly faster. 125-200 keys per minute (~8000-12000 keys per hour). I have seen this being done and they were amazingly fast! I'm no slouch, once I get my hand limbered up, but I don't think I can do more than 7,000 and I'd make a ton of mistakes along the way.

[@jamesslick4790]

Mechanical calculators impress me more than digital ones, LOL

[@frogz]

i was going to get skillshare but they didnt have any information on the topic of the study of the history of the pangalactric gargleblaster's cosplay recreations in the years between 1992 and 1994

[@Steve_R]

improbable as it might sound. two guys came by in a spaceship and took all the information with them, then muttered something about going to a restaurant somewhere.

[@leinadsee]

When the Curta calculator?