Method and apparatus for converting frequency signals representing characters to binary code

A system for converting selected characters to binary code data, comprising

• a plurality of means for producing signals of selected audio frequencies,
• a plurality of NOR gates,
• means connecting pairs of said frequency producing means to the NOR gates for transmitting to selected NOR gates pairs of frequency signals and producing a positive output signal from a NOR gate upon coincidence of a pair of frequency signals,
• wherein the output signals from the NOR gate represent selected code characters
• a plurality of channels consisting of a NAND gate, an AND gate and an OR gate connected in series, said channels representing code characters,
• means transmitting the output signal representing a code character from each NOR gate to the channel representing the code character to produce an activating pulse from the channel,
• a coincidence counter having output pins each output pin corresponding to a code character,
• means connecting the channels to the corresponding coded output pins of the coincidence counter,
• a clock means for providing clock pulses,
• means for transmitting the activating pulse to the clock means to activate the clock pulses
• means in said coincidence counter for applying positive pulses successively to the channels connected at the output pins,
• a coded counter for producing successively code characters at terminals of the coded counter,
• means for providing clock pulses synchronously to increment the coincidence counter and the coded counter to produce simultaneously a positive pulse at a coded output terminal of the coincidence counter and the corresponding code character in the output of the code counter, and remove from the channel which activates the clock the activating pulse to discontinue the incrementation and produce at the output terminals of the coded counter the code character represented by the activating channel.