
In 1973 Steve Rutt, Bill and Louise Etra developed a "scan processor" that was utilised in video productions by Nam June Paik, Steina and Woody Vasulka as well as Gary Hill. 56 With the "Rutt/Etra Scan Processor" signals of a black-and-white monitor can be modified. The signals are modified by controlling the voltage along the horizontal and vertical axes. It is possible to locate the images of a video input on different places of an image raster.
There's also a link to a clip of the EMS Rutt Etra Video Synth in there somewhere...