Posts in this category are intended to provide information on the technologies, mostly old technology, that were used to create the processors, imagery and sound. I should be excused if I include personal memories around the hardware and it’s construction; it is done as an attempt to provide history as well as the pure technology. I apologize in advance for my poor hand at drawing schematics, my scribbles were originally only intended for my eyes.

Many of of the chips used to create the early image processing tools are outdated which limits the usefulness of these schematics.

I seem to have a small repository of schematics as Rich Brewster left me with most of his own documentation including the work he did for the ETC (I have some of the originals to what is also in the ETC archive). I also have what I documented working with David Jones and others. As I might become overwhelmed by the time it takes to scan the paper, this process might be slow.

However obsolete, I will only post schematics for those circuits that are in the public domain or for which I have permission to post which for now will not include any Jones modules.

modular video synth

This Jones modular video synthesizer is comprised entirely of Jones designs. This synth includes a video patch panel made of an inset piece of hardwood with mini-jacks carrying 2vpp differential video. Subsequent modules used Plexiglass. The advantages of this standard is that it limits crosstalk and noise, and making a video signal negative one simply uses a cable that flips the polarity of the wires. It was thought for a time that this system would be embraced by Jones in general, however no synthesizer at the ETC uses the format. The system at the ETC patches standard single ended 1v video through a slide matrix. Using differential video was a great idea but as an unusual standard it only made sense for patching within the panels of multi module synthesizers, and other than a few of the Tuesday afternoon participants, it was an idea that was not really implemented. Unfortunately Jones has yet to manufactured multi module synths as Hearn did.

some history

My video hardware development work for the Experimental Television Center, and for Design Lab, included a contribution in building the last generation of custom Jones analog and digital image and sound synthesizers currently installed at the Television Center. I also have constructed various audio and video synths including a unique modular Jones video synthesizer.

early Jones ETC keyer w/ schematics

This was an early Dave Jones keyer. Rich Brewster documented and built it. We referred to this as the black box keyer because it was in a black box. This keyer moved around a bit, at times it was at the center, at times it was at Ralph's studio. I first used this keyer as a student working at the ETC in the converted photo lab studio (at that point the Center was still on Court Street in Binghamton). Years later when I was working for the TV center I lobbied to install it back into the ETC studio.