This IBM video is from 1965, back when computers took up an entire room, but it's still surprisingly informative today. Yes, it feels like something you might have watched in school as a kid, and some parts of it are particularly quaint -- like the explanation of punch cards, or the reference to a "television-type display." But the video actually provides a lucid overview of how computers actually work.
The narrator explains that it's easiest to understand a computer if you reduce it to five basic functions:
- Input, represented by a pair of spectacles.
- Memory, represented by a box divided up into different cubby holes.
- The calculating function, represented by an adding machine (an old fashioned predecessor to the pocket calculator).
- Output, represented by a typewriter.
- The control unit, represented by a numbered dial.
The narrator goes on to explain how each of these components could work in concert to execute a simple program -- calculating the average age of a family of five. The input would read each step of the program, the control unit would keep track of what step the group was on, the calculator would do the math, the memory would store the results of each step, and the output would type of the results.
Yes, that's a very simple example, but from those humble beginnings, all of modern -- and not so modern -- computing arises. "It seems extraordinary that with such limited capabilities computers can do so much," the narrator remarks.
But that's the theory still at the heart of today's computers, though even our smart phones operate at a much grander scale than IBM's 1960's mainframes.
