I actually owned several versions of the "Baby Calculator" along the way, used it in elementary school and the first year or two of high school.
I'm also old enough to have used a Monroe, at a steel company where I worked one summer. It was the upscale model that did multiplication. It was not any split-second result, though, unless your multiplication involved only single digits. Just for fun, I poked in two 10-digit numbers for a multiplication. It soon became apparent that we'd all be long dead and gone, along with our grandchildren's grandchildren, before it arrived at an answer.
Best to you,
Goober Dave
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My brother and I shared a a Little Professor when we were young 'uns.
I was given an old Olivetti adding machine as a curiousity when I was in my teens. At the time I was more interested in the old teleprinter which accompanied it, it being a source of stepper motors and the like for me to play with. I owe a lot of my interest in technical stuff to my dad, as kids we were surrounded by bits of machinery or one form or another.
Where I first started working in engineering (co-opted from 1966 - 1970, and then full time starting in 1971) we had several of the Monroe calculators, both hand-cranked and electric, in the office. What caught my eye one of the photos showing a Monroe sitting next to a phone. In our office, you were not allowed to use these machines if someone was on one of the phones near where they were placed as they made such a racket. I was also fun if someone accidentally divided by zero with one of the electric ones. The only way to get it to stop was to pull the plug. Eventually we got a Friden calculator...
...for the office. Eventually they bought a couple of handheld Texas Instrument calculators which were given to the department supervisors from whom you could 'sign one out' when you needed to use it, but it wasn't too much later than that when I bought my first calculator.
Up until then I pretty much used only my slide rule.
John R. Baker, P.E.
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To an Engineer, the glass is twice as big as it needs to be.
I actually used the Monroe in my surveying class in college and the Cannon in one of my summer jobs back in 1967. The "Little Professor" we bought for our oldest when she was four back in 1975.
Nice link, JAE. Like others I had, and used, this little Monroe in college. Completely manual operation... adding, subtracting and multiplication were quick but division was a little more tricky - had to listen for a bell to ring on each column indicating that you had turned the crank one turn too many and to go back one revolution. My uncle, a structural engineer, was a wizard with these machines. He would use various numerical methods to do calculations well beyond the basic four functions. One that I learned from his was to use the Newton–Raphson method of getting a good approximation of a square root.
IMHO, for typical engineering calcs (3 significant digits) a slide rule was superior (for everything except addition and subtraction, of course.)
I remember after our company purchased those first few 'office' TI calculators that you had to 'sign-out' for, I told my wife that as soon as the price dropped below $100, I was going to buy one for myself. Every Friday one of the local 'Stationary Stores' (when was last time you heard that term used?) would run an advert of their weekend sales and sure enough they finally listed a TI for $99.95. I told my wife that I wasn't going wait any longer and so I drove over there Saturday morning but when I got there they were all sold-out. However, the salesman showed me an SR-51 which they had just marked down to $149.95. Well at first I felt like this was some sort of 'bait & switch' situation (still not sure that it wasn't) but he was a good salesman because he asked me what I did for a living and when I said that I was an engineer he immediately pointed out that the 'SR' stood for 'Slide Rule' and that I had been using a slide rule at work that I really needed something like this and not some simply 'adding machine'. I was still a bit leery until he mentioned that it could do engineering unit conversions. Well I immediately scoffed at that since ANY calculator could do 'unit conversions', just look up the appropriate conversion factor and then multiple, or divide, your curent value to get the value in the units that you needed. But he NO, these were built into the SR-51. Sure enough, he flipped the unit over and on the back was a table of some 16 common conversions each with a code number. You would simply enter your current value then hit one of two button sequences (depending on which direction the conversion was going) and then 'code' number and you'd get the properly converted number, period. Well this sold me (as I said, he was a good salesman) and paid out the extra $50 (which back then was probably a full days pay) and I used it for many years, including when I took the second part of my PE exam in July 1976 (calculators were allowed as long as they were NOT programmable).
BTW, based on my research today verifying exactly which TI I purchased back there, I discovered that I should have hung onto it (can't remember what happened to it, I might have given it to one of my kids when they were school). Apparently the SR-51 is considered a 'rare' collectors item since it was replaced almost immediately with the SR-51A (which is probably why the store had cut the price since they originally sold for around $200) and there are collectors out there who will pay a pretty penny for one in good condition.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA Siemens PLM: UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
Texas Instrument's first "Slide Rule" calculator was the SR-10. I bought one in 1973, for about $100. Compared to a professional slide rule it was a joke, with only the four basic functions plus squares, square roots, reciprocals and the ability to use exponential notation. Used this SR-10 for the PE exam in 1974 for addition and subtraction, with my Pickett N4-ES (34 scales) slide rule for everything else.
I had a typo; it was an SR-51, for which I (my mom) paid $149.95 in the spring of 1975. The SR-10 looks remarkably like the RadioSh* 4-banger I bought for about $100. My mom was so pissed that I used the 4-banger for less than a year, before I wanted the SR-51. Luckily, I was the first-born, so RHIP...
TTFN
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I remember using a distressingly large number of the old mechanical beasts. I guess that is one consequence of geezerhood.
Thanks again for sharing this gem!
Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.
Hey, SlideRuleEra, I see that you're also a fan of 'radios what glow in the dark'. A favorite is my 1965 Hammarlund HQ-180AC...
When I was in high school (close to 50 years ago now) I messed with some of those old wooden consul sets by Zenith and RCA, mostly because they could receive shortwave. Back then I couldn't afford a Hammarlund (like the one above that I bought on EBay a few years ago) but I did put together a Heathkit that I had in my dorm room at college.
Anyway, if you don't already, I have a good source for replacement tubes if you ever need help looking for something.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA Siemens PLM: UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
John - Nice Hammarlund set. It is way to new for me, normally I stick with AM, Shortwave, or FM radios from the 1940's or before. Since the early 1960's I have been interested in shortwave reception, too. As a young teenager, received an Allied Radio "Knight Kit" shortwave set for Christmas one year. Assembled it and spent many happy hours tuning in the English language broadcasts from all over the world.
My current favorite set is a 1941 Stromberg-Carlson FM table model. After a complete rebuild, it works perfectly. The year 1941 is special, that is when commercial FM broadcasting began. Listen to this radio several hours per day.
Thanks for the offer on a vacuum tube source - I contact you if the need arises. Surprisingly most types in the consumer sets that I work with are quite plentiful and reasonably priced. When capacitors and resistors are replaced with modern components (which cost pennies and are highly reliable) tubes have a remarkably long service life. Years ago, tubes got a "bad rap" for short life, but the real problem was capacitor failure, which can easily "take out" a perfectly good tube.
Yeah, my Radio Sh* calculator looked almost exactly like that! Dang, I haven't a clue whether I even still have it. Still have almost every other calculator I've ever owned, except for one lost HP15C.
TTFN
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In case you were interested, HP re-released the HP15C in a limited edition two years ago. It is possible to pick them up quite reasonably, if you are so inclined. There are some bugs, but overall it is an excellent piece of kit.
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