What was this early-'70s calculator?

Back in the early '70s, before calculators-as-we-know-them, I had a mechanical calculator. It was a metal pad, about maybe 2 inches wide and 4 inches high, and maybe 1/4 inch thick. It had a vertical track with little holes for each decimal place. A stylus was used that fit into the holes, and you slid the tracks up or down, depending on whether you were adding or subtracting.

Does anyone remember this calculator, and what it was called?

And at the top of the tracks there was a slot to move the stylus over and drop the next track one notch, for carrying while adding? I remember those. I don’t remember a specific name, but in principle it was variation on the abacus. Perhaps mechanical abacus?

Possibly an Addiator, as pictured at the Museum of Pocket Calculating Devices.

It’s an addiator.

You’ll be looking for something like this then, I must say, I had no idea they were quite as old as the early 1900’s.


Wow, talk about a memory cascade!

I used to use one of these, when I worked for an insurance company in the 1960s. Once you got used to them, you would enter the numbers, work the lower side knob, then flip the carriage over one place (knob at bottom), and crank some more (crank, flip, as needed until calculation was complete). But the model shown isn’t the oldest one; the face is light-colored. The older ones had a dark top - black, or maybe dark, dark green. The first one I remember using was considerably more antique, and looked it.

I remember when we got the first electric(al? onic?) machine in. It went to the senior rater. Some months later, we got at least one more, because I had one then (I was #2). It seemed so cool to be able to push a button instead of having to crank.

I’m sure that Monroe Calculators either went out of business or was sold to somebody bigger, as the field developed. However, There Was A Time when this was by far the easiest and most reliable way to multiply and divide large numbers.

I have one in front of me as I type. It has 8 columns, is approximately 3" wide x 5-1/4" high and 1/4" thick. Nickel plated steel with a cadmium plated sliding ‘gate’ with inverted columns of numbers for subtracting. Included steel operating stylus somewhat similar to a PDA. Name is “Pocket ArithQmeter”. I have had it since the late 30’s or early 40’s

Thanks, guys. It seemed that I had been the only person who ever had one; though none of the links exactly matches mine. I wish I still had it.

I have one, and love the little thing! I always keep it with me, in my “Man-Purse” ® (forerunner to my infamous "Command Ruck"®). Here’s a picture. On the side it says “Made in West Germany”. Thus, I consider it another of my cherished relics of the Cold War. :smiley:

See, that’s why we beat the Soviets: we had better machines and they had abacusses . . . abacai?


Wang Laboratories producer of this nixie-betubed beauty that I got a chance to play with in the late 60’s, is however, no more.

panache45 writes:

> Back in the early '70s, before calculators-as-we-know-them . . .

By the early 1970’s, mechanical calculators were already a little old-fashioned. I remember that about 1973 I would balance my checkbook using the Wang Calculator in my college’s math lab. It was about the size of two shoe boxes and had about the power of a credit card-sized calculator from the mid-1980’s.