Some of you might enjoy this description of the other
extreme of manufacturing in which cost is no object.
I went to a shop in Oklahoma City years ago that sold
various new and surplus electronic devices. One device that
caught my attention was something that looked like a typewriter
keyboard and bore the legend "Field Data Keyboard." It was
military surplus gear of some kind and I probably only payed a
few Dollars for it, but it looked interesting to play with.
When I took it apart, I realized that it must have cost
a small fortune when it was new because the whole keyboard
worked on light beams. On the right end of the keyboard was a
metal block containing light bulbs that produced 6 or 8 beams
that shown the whole length of the keyboard in to 6 or 8 photo
cells at the left end. When you pushed a key, that key caused a
metal bar to drop down and block some of the beams of light.
There were notches cut in to the bars so that each key blocked
different beams when pressed and each bar had a shallower notch
at each end so that a machine could tell when the key was fully
down. In other words, there were no contacts to get dirty or
break. The only moving parts were the metal bars and the springs
to return them to up when you released the key.
There was even a solenoid with a locking bar that could
be tripped to prevent any key from being pressed and lock the
whole keyboard.
I don't know what this came off of, but I can imagine it
was probably several hundred or more US Dollars and what it
hooked to was probably unimaginably expensive.
It most likely came from the 1960's or 1970's and may
have controlled radar or similar systems. I still have it
somewhere and it is an interesting thing to show somebody, but
me thinks it's time of usefulness has passed. It is an
interesting testimony to what can be done when cost is not a
factor.
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