Abstract: There is provided an apparatus for machining surfaces to accuracies within the nanometer range by use of electrical current flow through the contact of the cutting tool with the workpiece as a feedback signal to control depth of cut.

Abstract: A phase-locked loop capable of generating a plurality of stable frequncy signals. This loop includes a plurality of voltage controlled oscillators which are sequentially coupled to the output of a phase sensitive detector by a multiplexer. RF switches then sequentially couple, in synchronism with the multiplexer, the oscillator outputs to a programmable divider which, in turn, is coupled to an input of the phase sensitive detector, the other input thereto being coupled to a reference oscillator. The dividing factors for the programmable divider are inputted thereto, in synchronism with the multiplexer, from a memory.

Abstract: In order to control subscriber access to selected television programs in a CATV system, nonstandard horizontal synchronizing pulses, having a greater amplitude and either a higher or lower pulse repetition rate than the contained horizontal synchronizing pulses, are selectively added to those television programs to be controlled. As a result, the television receiver of a nonpaying subscriber interprets the nonstandard pulses as being valid horizontal synchronizing pulses thereby preventing the receiver from synchronizing its line scanning with that of the television program rendering the picture produced therefrom unviewable.