This subject was motivated by discovering an old TI BA35 while I was cleaning out my office “archives”. I’m pretty sure you can figure out why archives is in quotation marks, since it implies some degree of organization. In any case, here’s the relic:
Fig01 TI BA35
Apparently I own a rarity. Texas Instruments (TI) has a good chunk of website devoted to their calculators. The only model 35 listed is solar powered.
I know mine is battery powered because I replaced the batteries to get it running. So I checked the Datamath Calculator Museum. Here’s what they have to say:
Fig02 Datamath Calculator Museum (click for larger image)
If that calculator is solar powered, I’d like to know where the solar panel is. My guess is that’s my calculator! The only differences are the locations of the company name and calculator model. Also note this:
Fig03 Calculator uses batteries (click for larger image)
My device completely!
A Brief History of TI Calculators
Datamath has a much more complete history than I could ever hope to compile. Before diving in, note that the Datamath site is owned and run by Texas Instruments.
Fig04 Datamath Calculator History Museum (click for larger image)
Texas Instruments invented the integrated circuit on May 10, 1954. These were used in pocket radios, the so-called “transistor radios” of the 1950s and 1960s. And were they ever popular: truly portable radios that could be carried in a pocket or purse. Everyone owned at least one. From the Datamath website:
The “pocket size” radio has four TI transistors. It also uses a TI subminiature output transformer. The transistors – technically known as n-p-n grown junction germanium triodes – are made in the Semiconductor Products Division. The transformer is a product of the Components Division.
Their application to the new radio receiver accounts for a large part of the increased production and employment in the two divisions in recent weeks. The Apparatus Division has also had a hand in the tiny radio, having worked on engineering problems and the machining and fabricating of models for the plastic case
And here’s a picture:
Fig05 transistor radio
The Integrated Circuit
TI scored a major coup in 1958 when Jack Kilby joined the company. He realized that a semiconductor company should stick to making products using semiconductor materials. In his own words,
… the only thing a semiconductor house could make cost effectively was a semiconductor. “Further thought led me to the conclusion that semiconductors were all that were really required — that resistors and capacitors [passive devices], in particular, could be made from the same material as the active devices [transistors]. I also realized that, since all of the components could be made of a single material, they could also be made in situ interconnected to form a complete circuit,” Kilby wrote in a 1976 article titled “Invention of the IC.”
Imagine that. A semiconductor company actually sticking to what they knew. Datamath continues:
Several executives, including former TI Chairman Mark Shepherd, gathered for the event on September 12, 1958. What they saw was a sliver of germanium, with protruding wires, glued to a glass slide. It was a rough device, but when Kilby pressed the switch, an unending sine curve undulated across the oscilloscope screen. His invention worked — he had solved the problem.
The First Pocket Calculator
The awkwardly-named Pocketronic was a collaboration between TI and Japan’s Canon. TI supplied the chips and Canon most of the rest. The project began in 1965 and was successfully completed in 1967. This device, remarkable at the time, could perform four – FOUR – arithmetic functions. You know them: +, -, *, /. Of course, the keyboard used ÷ instead of / (introduced because a standard keyboard does not have a ÷). (Someone who has more interest than me can investigate why the standard keyboard lacks a ÷.) Look at this beauty:
Fig06 Pocketronic (click for larger image)
The output was a thermal printer. (Any display available at the time would have taken way too much power.) The Datamath site includes a teardown of a Pocketronic. It required three large-scale integrated circuit (LSI) chips. Miniaturization has really been incredible, starting with increasing density on chips.
Enough. Dinner is almost ready. If you want more, visit the excellent Datamath site. It’s not pretty, but the information is all there.
Conclusion
See what happens when cleaning out old archives? I run across artifacts I’d forgotten. Don’t get me started on slide rules (yes, I’m that old).
TI finally incorporated September 9, 1997.
