Mr. Dave Cochran

He spent 25 years at Hewlett-Packard, starting as a part-time Test Technician in 1956 and departing as a celebrated HP Engineer in 1981. Between those two years, he worked on a huge number of projects including the HP 204B audio oscillator where he used transistors and a hugely ingenious double-spiral-cam potentiometer actuator to design the famous tungsten light bulb out of Bill Hewlett?s original audio oscillator design. He was working at HP Labs when Malcolm McMillan and Tom Osborne dropped by with two very different calculator prototypes. It was the legendary Barney Oliver, Grand Wizard of HP Labs who conjured the idea of merging these two very different machines into one massively powerful scientific calculator. McMillan?s design?called Athena?could perform transcendentals using Jack Volder?s CORDIC algorithms but it had a fixed-point architecture so it was not deemed accurate enough for repeated engineering calculations. Osborne?s design was barely more than a simple 4-banger calculator but it had a really elegant, floating-point hardware design based on the 1960s version of a VLIW processor. He got the job of trying to come up with a way to unify the two architectures. He writes ?I was looking at Osborne?s architecture and trying to figure out what an algorithm was. I even flew down to Southern California to talk with Jack Volder who had developed the CORDIC transcendental functions used in the Athena machine and talked to him for about an hour. He referred me to the original papers by Meggitt where he?d gotten the pseudo division, pseudo multiplication generalized functions. My job was to determine how many digits and what the operation time was required; what the architecture had to be; how many registers did we need, clock speed, etc.? Other people were coming back with their inputs on cathode ray tube display, keyboards [and so on]. Should we use transistors or small-scale integration? There was no large-scale integration, but there was medium-scale integration, MSI which meant maybe 10 transistors in a chip.? From his architectural contributions, plus substantial work from other engineers in HP Labs and Tom Osborne (who remained an HP consultant for many more years), HP introduced the HP 9100 Scientific Calculator in late 1968. It?s a marvelous machine and it was a real design breakthrough for its day. It also weighed 40 pounds and drew 70 Watts out of a wall socket. In 1972, the HP 35 Pocket Scientific Calculator crossed over from the realm of the impossible to the realm of the possible - a pocket scientific calculator that ran on three NiCd batteries in a pack.