General Electric Co., Computer Dept.
Electronic computers are built up of many “building blocks” like this one.
Logic problems abound in puzzle books, and many of us spend sleepless nights trying to solve them in our heads. An example is the “Farnsworth Car Pool” problem. Rita Farnsworth asks her husband if someone in his car pool can drive for him tomorrow so that she may use the car. Joe Farnsworth replies, “Well, when I asked Pete if he would take my turn he said he was flying to Kansas City today, but he’d be glad to drive tomorrow if he didn’t have to stay over and that his wife has been staying home lately and he will drive her car if she doesn’t go to work. Oscar said that since his own car is due back from the garage tomorrow he can drive it even if his wife does use hers, provided the garage gets his back to him. But if this cold of mine gets any worse I’m going to stay home even if those fellows have to walk to work, so you can certainly have the car if I don’t go to work.” This dialogue of Joe’s confuses Rita and most of us are in the same state.
Autonetics Division, North American Aviation, Inc.
Testing an assembled digital computer.
The instruction manual for BRAINIAC, a do-it-yourself computer that sells for a few dollars, gives a simple wiring diagram for solving Rita’s dilemma. Electrically the problem breaks down into three OR gates and one AND gate. All Mrs. Farnsworth has to do is set in the conditions and watch the indicator light. If it glows, she gets the car!
These are of course simple tasks and it might pay to hire a man to operate the vents, and ride to work on the bus when the car pool got complicated. But even with relatively few variables, decision-making can quickly become a task requiring a digital computer operating with Boolean logic principles.
Science Materials Center
Problem in logic reduced to electrical circuits.
The Smith-Jones-Robinson type of problem in which we must find who does what and lives where is tougher than the car pool—tough enough that it is sometimes used in aptitude tests. Lewis Carroll carried this form of logical puzzler to complicated extremes involving not just three variables but a dozen. To show how difficult such a problem is, an IBM 704 required four minutes to solve a Carroll puzzle as to whether any magistrates indulge in snuff-taking. The computer did it the easy way, without printing out a complete “truth table” for the problem—the method a man would have to use to investigate all the combinations of variables. This job would have taken 13 hours! While the question of the use of snuff is perhaps important only to tobacconists and puzzle-makers, our technical world today does encounter similar problems which are not practical of solution without a high-speed computer. A recent hypothetical case discussed in an electronics journal illustrates this well.
A missile system engineer has the problem of modifying a Nike-Ajax launching site so that it can be used by the new Nike-Hercules missile. He must put in switching equipment so that a remote control center can choose either an Ajax system, or one of six Hercules systems. To complicate things, the newer Hercules can be equipped with any of three different warheads and fly either of two different missions. When someone at the control center pushes a button, the computer must know immediately which if any of the missiles are in acceptable condition to be fired.