output. In the Design Device there will be two such oscillators. The stored waveform will be loaded from a sampled graph drawn by the artist and scanned by a conventional television camera.

Given that this small memory can serve to store waveforms, a method must be found to clock out its stored information. oscillators such as those found on the RuttEtra or Steven Beck's synthesizer must be synchronized to the rest of the synthesizer in order to produce stable patterns. While it is relatively easy to make a voltage controlled oscillator, it is difficult to maintain synchronization for an analog module. The Design Device uses the video sync generator itself as the clock for its memories. The rate at which the memories are read out is determined by a simple binary counter which is preset to the number of subdivisions it makes of the sync signals. Hence all the patterns produced by the memories are stable both with respect to the video signal and to each other.

The contribution of commercial manufacturers of television equipment must not be overlooked in describing the development of video synthesis. Every news broadcast these days uses chroma key backgrounds, and this technique can prove very handy for the artist. The trouble is that most synthesizers operated on black and white inputs which are synthetically colorized, and the standard chroma keyer must have separate red, green and blue inputs in order to work. The Design Device will have an encoded chroma keyer which will derive the RGB signals from a color tape input, so it will be possible to build generations of imagery by operating on sections of the image encoded in a particular color. This may sound like a major electronic undertaking, but the commercial manufacturers of television sets have put the chroma decoding circuits on three relatively simple integrated circuits. Building an encoded chroma keyer is simply a matter of opening up a color television and using its decoder circuitry. Paik and Abe perfored this operation on a Trinitron at the WNET TV Lab. Unfortunately they did not realize this application of their modification.

Another area in which broadcast television people have made great strides is in time base correction. For the mere sum of $12,000 the broadcaster can replace his $100,000 quad vtr with a time base corrector and a Sony video cassette. This means that an inexpensive vtr can be used as a source in a switcher. For an artist making a multi generational tape, such time base correction is essential. For an artist working on a shoe string budget, $12,000 for a time base corrector is out of the question. The Design Device will have two kinds of "pseudo" time base correction. It has a rescan system which will re enter a black and white image from an external tape source and even permit the luxury of relocating the input image into a new space in the frame. It will also use the cheap part of the big commercial time base correctors which is a digital memory system, only the Design Device will only have one bit of time base correction. This will eliminate the