OT: Toshiba BC-1412, fascinating vintage technology


Sorry for this Toshiba calculator post, but I couldn't resist. It's simply amazing how many electronic parts were needed in 1968 to make a basic desktop calculator work. See my pictures on Flickr. Enjoy!


Great photos, and a great illustration of why integrated circuits revolutionized calculators (and every other piece of electronics). The design of the Toshiba at its basic form is very reminiscent of the HP 9100 of the same era: A bunch of boards plugged into a chassis with nary an IC in sight. The HP 9100 calculator design is more advanced in several ways, but the construction philosophy is similar.


And the Nixie Tubes make it even more glamorous.

Pictures are great, indeed!


Luiz (Brazil)


Please, do not be sorry. I for one welcome all good technology. And as mentioned, the design resembles the HP9100, so it is HP related indeed.

Thanks you for the impressive set of pictures.

In time: do you allow me to use your pictures, credits surely kept, to show my students (computer science) how the 'good things' were made back then when their parents were just kids, if born yet?


Luiz (Brazil)

Edited: 11 Mar 2012, 12:12 p.m.


Of course you can use the pictures for any non-commercial purposes. Documenting old technology is one of the reasons why I put pictures on the Internet. When you take into account that this calculator was introduced in the year before mankind conquered the moon you may ask yourself how they managed to get there ;-)


Something else to think of...

First of all, thank you for your considerations. I appreciate.

You see, this technology still prevails, I mean, it is strong and reliable. Actual board computers from that time still work till these days, isn't that right? I tell my students, mainly the 'Conspiracy Theory' devotees, that the voyages to the moon were a step-by-step, fully documented conquering, provided by brainy people not usually found these days - at least not with the skills they'd shown in their time, way ahead the average. It was a consequence of the Mercury and Gemini programs, along with the many Apollo orbital and moon flights prior to landing. And that if there was a single bolt out of place, a single lack of time in the seconds, one small slack movement and a disaster might come out of it. Everything should follow a straight, fail-proof scheduling. It was like in the ballet: one small twist and you'd have a broken bone and never dance again.

Actually my strongest point against these 'fake pictures', 'primitive technology' and related subjects is that the ones mostly interested on finding a breach in the USA Space Program were the Russians back then. AFAIK, if there was a conspiracy to fake a moon landing, Russians from that time would do whatever needed to expose it and use it as a flag to celebrate their superiority.

Well, we're talking about the end of the 60's. People were too busy that time with a lot of dangerous stuff to be worried about this.


Luiz (Brazil)

Edited: 11 Mar 2012, 2:00 p.m.


I absolutely don't doubt that they were on the moon. As you said it was a a real masterstroke, a perfect ballet of human intellect, and I admire this achievement. I don't believe in any of the dozens (or hundreds, or thousands) conspiracy theories floating around.


At the list price of $1050 shown in that 1969 advertisement, that means it cost only the 2012 equivalent of $6485. Now I don't feel so bad about the $130 I spent in 1972 for a Bomar 901B four-banger, the mere 2012 equivalent of $705.


I expect those boards were not stuffed by machine, meaning the assembly labor cost would be astronomical.



although it is a curiosity of mine, I actually tried out some possibilities but I feel like stuck in my own knowledge/data bank.

Considering this picture, what kind of component are those three adjustable, 'motor-like' ones at the right side, slightly below the middle? I confess I have never seen something like those before. Adjustable coils? High-power variable resistors? Capacitors? Cannot think of anything else.


Luiz (Brazil)

Edited: 11 Mar 2012, 12:22 p.m.


I also wondered what these knobs are for, but I was not keen enough to adjust them and see what happens. I don't know enough about electronics to derive any meaning from tracing the connections.


They look like potentiometers to me, trim pots where not always tiny.


Display brightness?


They are on what looks like the power supply PCB, what with all the capacitors, and the transformer to the left. I'm guessing they adjust the output voltages of the power supply.

As the components aged and power supply drifted, you could probably "fix" a lot of issues with this machine in the shop using a Heathkit VTVM and a #2 flatblade Craftsman screwdriver. How many of us here had those as "primary" tools on our bench?

The ubiquitous 317 and 78xx/79xx linear regulator ICs didn't make the scene until the 1970s, I believe...


Thank you, excellent pictures!

Ha ha, germanium transistors! I still remember working with those!

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