Abstract: A circuit which prevents a telephone or a plurality of telephones from making unauthorized or restricted calls to specific numbers or unspecific groups of numbers. The restricted call numbers may be local or toll call. The circuit is disabled either on a call by call basis, or indefinitely by entering a user defined pass code. The circuit is programmable from any commercially available touch-tone phone. When in the call restriction mode, the circuit detects outgoing calls by detecting and decoding standard `DTMF` burst. Upon detecting the first valid tone, the circuit isolates the user from the central office equipment. The circuit then parses the first and all following DTMF bursts and compares them against preprogrammed internal lists of fixed or relative restricted numbers.

Abstract: A Universal Digital Data Copying System for the blind copying of digital information from electromagnetic media such as flexible discs is disclosed. The system provides a master drive and a slave drive by which information is read from the master drive, timed by a phase-locked oscillator, converted by a serial to parallel converter, and controlled by a controller and stored in the high speed memory buffer. The output of the controller is fed to a parallel to serial converter and precompensation circuit. Thereupon the information is written at the slave drive at a fixed clock rate. A verifier to test the quality of the recording is also disclosed. By the addition of other drive units, the system provides for any desired number of copies to be made concurrently from a single master. The invention thus provides a copying system independent of the media employed, format or encoding scheme used.