Original poster: "Gary Peterson" <g.peterson@xxxxxxxxxxxx>Could be METHOD OF SIGNALING, U.S. Patent No. 723,188, Mar. 17, 1903 and SYSTEM OF SIGNALING, U.S. Patent No. 725,605, Apr. 14, 1903.
Tesla's work on the "telautomaton" led him to devise methods for selectively activating any of several wireless receivers that involved multiple transmissions on multiple frequencies. At the receiver, each one of the individual frequency components had to be tuned in, in order for the receiver to respond-the AND logic function. A patent application was submitted on July 16, 1900. During the review period, the Patent Office told Tesla that another application for a similar concept had been received from Reginald Fessenden, and in 1902 a U.S. Patent Interference investigation ensued. Tesla's claims were supported and he was granted the "System of Signaling" and "Method of Signaling" patents-both describing the electronic AND-gate circuit. After WW II when computer hardware manufacturers tried to patent digital logic gates in general, the U.S. Patent Office asserted Tesla's turn-of-the-century priority in their implementation. These same patents also describe essential features of the spread-spectrum techniques known as frequency-hopping and frequency-division multiplexing. The Patent Interference proceedings transcript is in NIKOLA TESLA: GUIDED WEAPONS & COMPUTER TECHNOLOGY, Leland Anderson, Ed., Twenty First Century Books, 1998.
Original poster: <davep@xxxxxxxx> A related, sort of inquiry: It has been said that one of Tesla's patents was cited as 'prior art' in early (1950ish?) Solid State patent law. Does anyone know which? I've not heard it identified... best dwp