Hiro Moriyasu

I like to take a break from politics but I hate to do it with obituaries. I have discussed the passing of exceptional scientists and engineers here before but Hiro Moriyasu is different. I knew and worked with him at Tektronix.

Portland inventor Hiro Moriyasu dies

Hiro Moriyasu, the inventor of the digital oscilloscope and a patent holder for many other technologies, including one of the first personal computers, died in his Southwest Portland home Sunday.

Moriyasu, 70, worked as an engineer at a company he founded up until his death. His 1971 invention, which he developed while working for Beaverton-based Tektronix, improved upon the old analog oscilloscope by allowing the visible image of moving electrons to be saved and documented in digitized form.

"The magnitude of his work was such that everybody else followed to do what Tektronix did," said Leon Orchard, chairman of the board of Ortech Industries who supervised Moriyasu at Tektronix. "He was a brilliant engineer with a gift for understanding what was fundamental and what was not."

In 1974, Moriyasu created one of the first personal computers, the 4051, an invention that caused IBM to take its earlier model off the market, said Luis Navarro, an engineer at Precision Interconnect, a division of Tyco International Ltd. who worked with Moriyasu at Tektronix and at two later startup companies. He added that Tektronix wasn't interested in supplying the consumer market, so it missed the potentially fruitful opportunity to further develop Moriyasu's design.

I worked at Tektronix as a manufacturing engineer in the CRT division. At the time Moriyasu developed the digital oscilloscope and the 4051 computer the best microprocessors were 8 bit which meant only 64K of memory could be addressed. As a result there was little or no memory for video. The solution was the Tektronix direct view storage CRT. The CRT itself was a storage device. Early computer graphics was built around the DVST (direct view storage tube).


The Tektronix 4051 was the first desk top computer, although it was best if you had two desks since the 4051 filled one of them. Programming was in TEK Basic and programs were stored on a tape drive. The cost in 1975 was $6,000 with 8K of memory.
If Tektronix had chosen to further develop the 4051 it might have been the IBM of today. I believe that one reason they didn't was IBM was our largest customer for the DVST graphic displays.