Patent GB-767192-A (GB)
Title: Improvements in and relating to data transfer apparatus
IPC: G06K3/00
Filed: 1952-05-29
Abstract: 767,192. Digital electric calculating apparatus. LYONS & CO., Ltd., J., and PINKERTON J. M. M. May 27, 1953 [May 29, 1952], No. 13669/52. Class 106 (1). A data transfer apparatus comprises a movable magnetizable member, a plurality of magnetic heads for recording on and reading from a plurality of tracks on the member a printer adapted to print a plurality of characters in a cycle of operation, means for synchronizing the movement of the member with the cycle of operation of the printer, and means for deriving, by repeated scanning of the tracks, timed signals for controlling the printer. General. In the described embodiment a standard printing mechanism 20 of the type used in record-card controlled tabulators is employed in which one complete line having a maximum of 100 digit positions is printed in a single operation. The setting up of the type bars requires up to 100 inputs which, in the present case, are derived from that number of tracks on a rotating magnetic drum 21. Each track comprises two diametrically opposed sections of 15 digit positions each on which pulses are recorded at angular points corresponding with the values of the digits (or alphabetical characters) represented. The provision of two sections enables a record of all the characters for one line to be made on one section while a record of all the characters of a preceding line is being reproduced by the printing mechanism. Recording on the drum. Successive result numbers to be printed on the same line are recorded in turn, each number taking up as many tracks on the drum as there are printing positions allotted to it. A result number which, in the described embodiment, may comprise up to twelve digits, is derived from a reconverter 31 which converts binary series-mode data (e.g. from a computer) into decimal, ú s. d. &c., and passes the result to a compositor 32 for storage on multi-cathode counting tubes-one character per tube. Read out from this device is controlled by stepping pulses derived from a phonic motor mechanically coupled with the magnetic drum, but this process is not allowed to start until a pulse arrives on line 60 signalling that one half of the drum has been cleared and is ready to receive a new line. The stepping pulses drive the stored data out of the multi-cathode tubes of the compositor 32 to a unit 34 which comprises a distributer switch and a plugboard. According to the arrangement of the latter, the first number, or group of characters, received, may be directed to any of a similar number of output lines corresponding with predetermined printing positions. The output lines 36 are connected to recording heads 25 whereby the number is recorded in selected tracks on the drum 21. A signal on line 64 serves to step the distributer switch in the unit 34 to the next position, and when the appropriate half of the drum 21 again becomes available, the next number from the reconverter, if received in time, is transferred through another section of the plugboard to another set of tracks on the drum. Successive numbers are dealt with in a similar manner until a " line end " signal is received. This is fed to a unit 46 to arrest the recording process and to a unit 45 to arrange for subsequent recording on the other half of the drum. This last unit does not respond, however, until signals are also received indicating that read-out of the previous contents, erasing, and printing, have been completed. The circuits are then changed over to bring the newly recorded. half of the drum into operative relation with the reading heads 26, and to clear the other half to receive the next line of numbers. Reading out from drum to printer. A complete drum track comprises 30 digit positions in two sections of 15 digit positions each. Each of the 15 positions in the section available for read out is examined in 15 successive revolutions of the drum; during this time the printing bars are allowed to move through a corresponding series of 15 positions, individual bars being arrested according to the position of a signal or signals in the corresponding drum track. A 31-way divider provides examination pulses advancing through the digit positions, cycle by cycle to gate the outputs from the reading heads to the print selection solenoids. Thus, transfer of data from the compositor 32 to the printed sheet is controlled by timing pulses synchronized with the rotation of the drum 21, while transfer between the reconverter 31 and the compositor is on an independent time base. Hence the necessity for control signals such as " line end ", " reconversion complete ", &c., between the two systems.