Programmable frequency-shift-keying acoustic transmitter to transmit repeated bit digital message via telephone lines

Claim 1

A programmable acoustic transmitter operable to transmit a repeated digital message over conventional telephone lines into a digital computer using audio frequency-shift-keying transmission techniques, comprising: a first timing circuit operable to apply power to said transmitter for a fixed period of time, a clock generator for generating a predetermined bit per second baud rate with logic clock pulses, a decade counter having said clock pulses connected thereto, a decimal decoder having the two state logic pulses from said decade counter connected thereto, a 3 -bit binary counter incremented one count per 10 clock pulses of said decade counter, a diode matrix, a data selector having said 3-bit binary counter and said diode matrix connected thereto to generate said mark signal and a space signal, an oscillator connected to the output of said data selector to generate a frequency signal indicative of a mark and a space signal for transmission on said telephone lines, said diode matrix having the outputs of said decimal decoder connected thereto for determining the bit pattern of said transmission having a first vertical column of diodes grounded during each count of said clock and a horizontal row of diodes connected to said data selector during ten of each of said clock pulses, a plurality of switches connected to said diode matrix for programming certain ones of said bits, reset means for resetting said counters.