About the author JOHN A. C. BINGHAM received a BSc from Imperial College, London, in 1956, and an MSEE from Stanford University in 1961. He has worked for twenty years in data transmission--primarily concerned with the telephone network. In 1972 at Vadic Corporation, he invented the VA3400, the first full-duplex 1200 bit/s modem, which ushered in a new era of high-speed, full-duplex data transmission. Until 1985, he was manager of the Advanced Development department of Racal-Vadic, a Milpitas, California subsidiary of Racal Electronics PLC, specializing in modems and multiplexers. He is a seni...