From John: "I'm guessing there are still some nixie equipped systems out there which need the upgrade. When they fail I don't know who would repair them. HP had their own nixie driver chip which was quite different from the 7400 series part. and they don't offer it anymore." The picture at left shows two 5505 displays, the lower one with John's LED upgrade. He has done other extensive modification and upgrades to his display. Contact John for more information.
John emphasizes the use of laser interferometry in the semiconductor industry. He says, "Did you know that without the HP interferometer there would be no IC's. Every chip is made with a wafer stepper. It positions the chip for exposure for each of the step and repeat positions. This happens repeatedly for each layer. The accuracy is controlled by an HP laser. "
John also graciously made available scans of the seminal articles from HP Journal describing the design and development effort put into the laser interferometer systems.
|Contact John Youngquist||1970 HP Journal Articles||1971 HP Journal articles|
Communicate with Dave Meier.