Electrical apparatus for monitoring a record tape

Claim 1

APPARATUS FOR SENSING THE LENGTH OF A RECORD OF STORED INFORMATIONAL DIGITAL DATA AND CLOCK DATA ON A MOVING MULTIPLE CHANNEL MAGNETIC RECORD TAPE COMPRISING MEANS SENSING THE PRESENCE OF EACH DATA INDICATOR IN EACH CHANNEL ON THE TAPE, A CLOCK DATA AMPLIFIER CONNECTED TO RECEIVE ON ITS INPUT CLOCK DATA REPRESENTING SIGNALS FROM SAID RECORD TAPE BY WAY OF SAID SENSING MEANS, A PULSEFORMING CIRCUIT CONNECTED TO THE OUTPUT OF SAID AMPLIFIER, A PAIR OF GATING CIRCUITS EACH HAVING AN INPUT CONNECTED TO AN OUTPUT OF SAID PULSE-FORMING CIRCUIT, A TAPE READ-FORWARD SIGNAL INPUT CONNECTED TO ONE INPUT OF ONE OF SAID GATES, A TAPE READ-REVERSE SIGNAL INPUT CONNECTED TO AN INPUT OF THE OTHER OF SAID GATES, A READ GATE DELAY SIGNAL INPUT CONNECTED TO AN INPUT ON BOTH OF SAID GATES, A BISTABLE CIRCUIT ADAPTED TO BE SELF-RESETTING A PREDETERMINED TIME FOLLOWING THE APPLICATION OF AN INPUT SIGNAL, FIRST BUFFERING MEANS CONNECTED TO THE INPUT OF SAID BISTABLE CIRCUIT AND TO THE OUTPUTS OF SAID PAIR OF GATING MEANS, A THIRD GATING MEANS, DATA SIGNAL AMPLIFIER MEANS CONNECTED TO RECEIVE INFORMATIONAL DATA FROM ALL CHANNELS EXCEPT THE CLOCK CHANNEL OF SAID TAPE, SECOND BUFFERING MEANS CONNECTING THE OUTPUT OF SAID AMPLIFIER MEANS TO AN INPUT OF SAID THIRD GATING MEANS, MEANS CONNECTING THE OUTPUT OF SAID BISTABLE CIRCUIT TO THE INPUT OF SAID THIRD GATING MEANS, AND MEANS CONNECTING THE OUTPUT OF SAID THIRD GATING MEANS TO THE INPUT OF SAID FIRST BUFFERING MEANS SO THAT INFORMATIONAL DATA SIGNALS MAY BE USED TO SET SAID BISTABLE CIRCUIT ONCE SAID CIRCUIT HAS BEEN SET BY CLOCK DATA SIGNALS.