The Last Byte

TeslaandANDgates

Mel Breuer University of Southern California

&DOYOURECALLlearning about Nikola Tesla back in These efforts led him to devise methods for your college days? He’s the guy who was pushing for selectively activating any of several wireless receivers alternating current while old Tom Edison was stuck on (he called this ‘‘the art of individualization’’) that DC. Well, you probably didn’t hear too much about involved multiple transmissions on separate frequen- Nikola, because he sold some of his patent rights on cies. At the receiving end, each one of the individual generators to Mr. Westinghouse, and that was that. But frequency components had to be tuned in, in order Nikola was a brilliant engineer and scientist and made for the receiver to respond—the AND logic func- incredible contributions in many diverse areas, such tion.… [Tesla] was granted protection under the as radar and radio. ‘‘System of Signaling’’ and ‘‘Method of Signaling’’ Well, that was then and this is now. patents—both describing the AND-gate circuit. After My wife Sandy and I are in a movie group that meets World War II when computer hardware manufac- once a month. At one of our meetings, I was asked to turers attempted to patent digital logic gates in lead the discussion on a movie called ‘‘The Prestige.’’ general, the U.S. Patent Office asserted Tesla’s turn-of- So, off we went to the movies to see what we got our- the-century priority in their electrical implementation. selves in for. ‘‘The Prestige’’ focuses on two magicians competing to best each other with incredible tricks. To This guy is intruding on my territory! I have been develop the ultimate ‘‘transporter’’ trick, one of them teaching logic design since 1965. I have reviewed and/ solicits the help of the famous Nikola Tesla, now in or read nearly 100 texts on the subject, none of which seclusion somewhere in Colorado Springs, where he mention Tesla. I’m in shock! What are the chances that has been trying to develop several new theories while I am assigned to lead a discussion of a completely avoiding interference from Thomas Edison. fictionalized film, You can imagine how excited I was to get home And one of the pivotal characters is based on an EE; from a movie which, in my mind, was about the career And he has the first patent on an AND gate; of a famous electrical engineer! To begin working on And the AND gate is central to my area of research; my presentation, I went straight to Google and And…? Wikipedia, and I found a lot of information on the more than 100 patents and devices that Tesla had So, I wonder, who has the first patent on an OR invented. One passage in particular caught my gate? I think I smell a good script here. ‘‘Sandy, get me attention because it contained the word ‘‘logic,’’ Universal on the phone!’’ & which was out of place with all the analog electrical devices described. Chasing down the background Mel Breuer is a professor of electrical engineering material that led the author to use this word from my at the University of Southern California. Contact him at domain of work, I found the following passage (from [email protected]. http://www.tfcbooks.com/teslafaq/q&a_024.htm, Twen- ty First Century Books): & Direct questions, comments, and contributions about this department to Scott Davidson, Sun In New York City in the mid 1890s, Tesla’s work was Microsystems, M/S USUN07-107, 324 N. Mary Ave., focused on the development of an independently Central Research Park, Sunnyvale, CA 94085; scott. remotely-controlled device—the ‘‘telautomaton.’’ [email protected].

624 0740-7475/07/$25.00 G 2007 IEEE Copublished by the IEEE CS and the IEEE CASS IEEE Design & Test of Computers