Patent GB-830509-A (GB)
Title: Improvements in or relating to the storage of electrical signals
Inventor: BAKER GEORGE THOMAS
IPC: H04L12/54
Filed: 1955-07-13
Abstract: 830,509. Electric digital-data-storage apparatus. BRITISH TELECOMMUNICATIONS RESEARCH Ltd. July 2, 1956 [July 13, 1955], No. 20330/55. Class 106 (1). [Also in Group XL (b)] In a storage arrangement for telegraph signals the elements of the signal are stored as a pattern on a register and then passed at a much higher rate to storage on a magnetic drum from which they are subsequently transferred to a further register from which they are transmitted at normal telegraph speed over an outgoing line. Storage of received signals. A gate RC1 opened by the incoming start pulse passed through delay network DN, providing a delay of 10 m. secs. in combination with a pulse from the tube H1 of the distributer H1 ... F1 operates a toggle circuit G1 so that a multivibrator MV1 is set into operation and passes pulses via a shaper Q to operate the tubes A1 .... F1 in succession, a tube which is ignited priming the subsequent tube and extinguishing the previous tube. The output of the final tube FI is applied to a gate RC3 which is opened by the next Q pulse and operates the circuit G1 to stop the vibrator MV1. This pulse also fires the tube H1 which extinguishes F1. The Q pulses in combination with pulses from the relay IR open gate RC2 so that the code elements are sampled at their middle points and by means of the pulses from A1, B1 ... E1 registered on the members AM ... EM. The pulse from RC3 which restores G1 also operates to transfer the code pattern on AM ... EM to AN ... EN and to operate the element STN to register the start element. When a track on the drum is free, a pulse from the amplifier RM1 together with a clock pulse over conductor 2 from the member STN operates the toggle MA which in conjunction with a pulse U1 from the clock track 1CT opens gate RC12 and over conductor 4 operates shaper circuit SY1 and toggle T1. The shaper SY1 also operates element AC1 and the output of TI opens gate RC13 so that over conductor 1 pulses U1 from RU1 operate pulse shaper P1 which effects the sequential firing of elements BC1 ... EC1. When EC1 fires, its output in conjunction with the next P1 pulse ignites HC1 which cuts off EC1, and also opens gate RC4, which restores the toggle T1 so that gate RC13 is closed to the clock pulses and the input to the shaper P1 is cut off. Pulses stored on the tubes AN ... EN selectively open the gates RC5 ... RC9 primed in succession from AC1 ... EC1, and pass via circuit RA1 and gate RC10 to a circuit RA2 and thence over conductor 7 to amplifier WAS also controlled by a strobe amplifier RAR. The output of the write amplifier WAS passes via track selector TS1 to the appropriate track STT on the drum. A reverse pulse U1 from the amplifier RU1 restores the toggle MA so that no further pulse is applied to shaper SY1. The start toggle STN is reset by the first clock pulse passed by from P1, and the gate RC4 resets the storage members AN ... EN. The elements of a signal are recorded in interlaced manner in different sectors of a drum track, as described in Specification 818,773, the elements being, for example, recorded in six regenerative loops on a drum track. When the reading head is operated by a "1" it causes the writing head to write " 1 " in that position and a " 0 " in the following position, this operation being effected by a clock write-amplifier WA1 which is controlled by gate RC12 and circuit RA3 in response to the operation of the toggle MA and a pulse U1 from RU1 in conjunction with a strobe pulse from amplifier RAR. The next element on the track resets MA, and the next five pulses are obtained over RC13 due to the operated condition. The potential fed to WA1 also extends to the shaper V1 providing an output pulse which in combination with a pulse U1 from RU1 extends to the right-hand side of WA1 to cause a zero to be written. When a track STT is full, the switch control circuit TSC1 is operated from gate RC14 which is opened by pulses M1, U1 in combination with a pulse from the toggle X which is operated by gate RC12 which is opened by pulses from MA and U1. Retransmission of stored signals. Retransmission can take place if the register JE, AJ ... EJ is free, providing a pulse on conductor 8, and also if an outgoing line is free so that potential is present on conductor 14 with the result that a pulse MO from the marker track MT can open gate RC16 operating toggle MB, and consequently gate RC19 is opened by pulses UO derived from the outgoing clock track and the store read amplifier RAS. When gate RC19 opens, the toggle Y is operated and a pulse also supplied to signal shaper SYO operates toggle TO and also the first tube ACO of the outgoing drum clock counter. Toggle MB is reset by the pulse UO and the output of TO is extended over conductor 10 to open gate RC18 so that subsequent clock pulses drive the counter through positions BCO ... ECO. Additionally, the pulses from TO and ACO operate the circuit G2 to start the multivibrator MV2 for transmitting the outgoing signals. The pulses from MV2 are passed through a shaper Z and drive the timing generator 1 ... 15. The output of TO is also combined with clock pulses over conductor 11 and the output of RAS over conductor 13 to operate shaper SL which is effective to pass the signal elements on the drum storage track to the members AJ ... EJ from which the signal is transferred to the members AK ... EK of the outgoing register by the operation of gate RC22 by the output of the element 14 of the timing circuits 1 ... 15, which also sample the elements of the signal, and through gates RC23 ... RC28 operate the circuit RA5 and via amplifier AS the output relay OR having its contact OR1 connected to the line L3. The pulses for driving the counter from BCO to ECO are obtained from the circuit PO, and when ECO has been operated, the next pulse from PO resets the trigger TO to cut off PO. Also when JE is reset, its output pulse in combination with a pulse from RC22 resets gate G2 so that the operation of the multivibrator MV2 is arrested. When a track has been completely scanned, the toggle Y is operated over gate RC19 and controls gate RC17 so that the next clock pulse operates the track selector control BCO to actuate the unit TSO to change the track, and also energizes circuit EC to erase the signals on the track from which transmission has taken place. The multivibrator MV2 may be adjusted to provide different speeds of signal retransmission, e.g. 45.5, 50 or 75 bauds. A circuit may be incorporated to provide an alarm if writing is taking place on track n-2, when the track n is being read i.e. when there is solely one complete track with no signals recorded thereon.