[cctalk] Re: Other input devices.

On Sat, 2024-04-13 at 07:58 +0100, Dave Wade G4UGM via cctalk wrote: As a freshman, I noticed that the HP Digital Slide Rule 6-digit pocket calculator was only $600. I suggested to myy college buddy Ed Kelm that it ought to be possible to build a desk calculator that used a TV for the display. That never happened, but Ed held onto that thought and eventually designed the Lexitron dedicated-logic word processor. It had a landscape-format screen. Vertical scrolling was done by typewriter- platen-like knobs on both sides of the screen. Margins were set by the same kinds of sliders as on a typewriter. As you can imagine, training for experienced secretaries was less than half a day. Documents were stored on 1/4" three-track tape cassettes using a drive invented by another school-days chum named Cliff Tedder. Because of problems with the Orange County, California, power system, where voltage ranges of 90-130 volts were common, Ed invented the now well-kinown switching power supply -- and Lexitron kept the patents so Ed got nothing but a salary from it. It rectified line voltage, regulated it to 90 volts, which ran a 20 kHz oscillator (so that the transformers required far less iron), and ultimately produced well-regulated power for the electronics. Raytheon bought Lexitron, and pounded it into the ground. Ed ultimately took his instance of it to a landfill because he couldn't find a computer museum that wanted it.