Automatic Program Controls Automatic Program Controls

Could computer programs be controlled by music box cylinders? Certainly they could. In the happy, innocent childhood of electronic computers something of the kind was tried. The music box with a repertoire like "Annie Laurie" would just be big enough for a little program. The program for making out the payroll we mentioned previously comprises about 50 instructions. To set the switch-points for an instruction an average of 35 bits in the (2/5) code, including fourteen "1"s and twenty-one "0"s would be required. The cylinder of the music box would accordingly have to have 14 times 50 = 700 pins, and 21 times 50 = 1050 places without pins. That sounds a lot, but it would not scare any experienced maker of musical boxes. For even "Annie Laurie," to be properly played, needs about 600 pins (if really elaborate instrumentation is provided to do full justice to the melody, 1.000). The number of places without pins is between five and ten times as many.

For elementary programs, therefore, the music box could undoubtedly be taken into service as a program interpreter. But unfortunately most programs are bigger affairs; they are often composed of several thousand instructions. Anyone who wanted to have such programs put into effect by a spiked cylinder could experiment at arranging Wagner's "Lohengrin" (played in full, it takes four hours) for presentation on a musical box. The essential conditions would be just the same: the roller of the box would merely have to be able to swell to the dimensions of a gas storage tank.

Even if "Lohengrin" is never likely to be recorded in its entirety for a music box, there is no reason why we should not consider how this could be done in theory. It might be possible, to simplify matters, for the instrument to be assisted by sub-boxes, each of which is assigned the duty of playing a certain part of the melody, a theme that is frequently repeated. The main box has to be fitted with special pins at suitable places to trigger off the sub-boxes into action at the appropriate times. While a sub-cylinder is rotating, the main cylinder naturally is stationary. A switching pin on each sub-cylinder, as soon as the program of a sub-cylinder has been completed, starts the main cylinder rotating again. The whole apparatus, admittedly, is rather complicated. But a skilled maker of music boxes would be able in this way to reduce the size of all the machinery needed for "Lohengrin" to about a third.

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Kybernetik - Was ist das?

First printed in Germany: 1963

 

Cybernetic Computer and Electronic Brain


The fascinating story of how computers work in clear, non-mathematical language