n's office on one of his trips west. This generator, built to Rechtin's specifications, was used to extend Rechtin's hand-calculated table of m-sequence generators from a shift register length of at most 7, to lengths up to 20 (see Figure 2.26). Sol Golomb, then a summer hire at the Glenn L. Martin Company in Baltimore, MD, first heard of shift register-generated sequences from his supervisor, Tom Wedge, who in turn had run across them at a 1953 M.I.T. summer session course on the mathematical problems of communication theory. (This meeting included an elite group of the founding fathers of infor- mation theory and statistical communications. See Figure 2.27.) On the other hand, Neal Zierler, who joined Lincoln Laboratory in 1953, recalls discovering shift register generation of PN sequences while looking for ways to simplify the SS signal generators used for the F9C system. Early Spread-Spectrum Systems Golomb's [170], [177], [178] and Zierler's [179]-[181] work established them as leading theorists in the area of pseudonoise generation. However, Zierler's shift register-generated sequences were never used in the F9C-A system since they possessed cryptanalytic weaknesses. Golomb's work gained fur- ther recognition after he joined JPL in August 1956. Madison Nicholson's early attempts at PN sequence design date back to 1952 [137]. Nicholson's first exposure to the pseudorandomness properties of linearly recurring sequences probably came from Allen Norris, who remembers relating to Nicholson ideas developed from lectures by the noted mathematician, A. A. Albert, of the University of Chicago. Coworkers recollect that Nicholson used paper-and-pencil methods for finding a per- fect word of length 43. Jim Green, in due course, joined in this exploration, Figure 2.27. Cut from a 1953 photograph of a summer session class on mathemat- ical problems of communication theory, this picture salutes (from left to right) Yuk Wing Lee, Norbert Wiener, Claude Shannon, and Robert Fano. It is ironic that Wiener could not prevent th