GB838786A - Improvements in or relating to signal translating apparatus - Google Patents

Abstract

838,786. Electric digital-data-storage apparatus; sensing record cards. INTERNATIONAL COMPUTERS & TABULATORS Ltd. March 1, 1957 [March 5, 1956], No. 6818/56. Class 106 (1). Parallel-to-serial signal translating apparatus comprises cyclically operable switching means for testing, during each cycle, all input channels in succession for the presence of a pulse, a shifting register for storing a different character representation during each cycle, and means for reading out the stored representation each time the switching means detects a pulse to form a serial pulse train. As described, record card sensing means 47 controls a group of triggers 48 which are reset by cam contacts 49 at the end of each index point. During the sensing of each row of the card a counter 12, operated by clock pulses from a source 13 which is synchronized with, and may be a track on, a drum 58, is taken through a cycle during which output signals on lines 16 are applied to a diode decoding matrix 15 whereby output lines 17 are energized in sequence. Thus a series of gates 50 connected between the triggers 48 and the lines 17 pass a series of signals to a gate 51 equivalent to the holes reading across one row of the card. In order to express this information in binary-decimal form a four-bit shifting register 54 is arranged to register the value of the card row which is being sensed at any time. To provide for this the value " 9 " is entered into the register by the operation of cam contacts 43, 44 at the beginning of a card-sensing cycle and, as each index point passes, a signal derived from cam contacts 6, 8 conditions a subtractor 55 in the feedback circuit of the shifting register 54 to reduce the digit registered by unity. At the appropriate time, with each opening of the gate 53, a serial binary pulse train representing the decimal digit in the register 54 is fed to a recording head 75 whereby a serial representation of the data on the card will be recorded on the drum 58 at the end of the sensing cycle. A device 56 provides for inhibiting the gate 53 so as to limit the recording of data on the drum 58 under control of the counter 12. Specifications 738,269 and 838,787 are referred to.