Patent GB-881911-A (GB)
Title: Improvements in or relating to statistical record reading devices
Inventor: SMITH KENNETH LESLIE
IPC: G06K7/016
Filed: 1958-10-22
Abstract: 881,911. Record card apparatus. INTERNATIONAL COMPUTERS & TABULATORS Ltd. Sept. 4, 1959 [Oct. 22, 1958], No. 33868/58. Class 106 (1). Reading means for a moving record card having upper and lower curtates (i.e. O, B, A zone and 1-9 zone) has sensing means for all card positions and a re-coding device for each curtate, signals from O, B, A zone being passed to one and those from the 1-9 zone being passed to the other, a code control device connected to the re-coding device for the upper curtate (O, B, A) to control its operation and timing means operable during the sensing of each card column to condition the re-coding devices one after the other so that the sensed signals from the upper and lower curtates are re-coded and transmitted successively. The record is sensed column-by-column as it passes under a row of photo-cells PA, PB, PO and P1-P9, Fig. 2, and, during the time that the perforations of each column are under the photo-cells, two read-out pulses are generated. These are produced as described in Specification 881,910 in a scale-ofeight counter 28 receiving eight clock pulses in each column period from a disc 19 rotating with the card feed, counting being started when the leading edge of the card is detected by the sensing means. The counter produces timing pulses at the counts of two and three which pulses are used to read out first the data in the 1-9 zone and then the data in the O-A zone. The card has forty columns and the read-out pulses are applied to a shift register 43 having four initial stages for the blank leading edge of the card, eighty stages, two for each card column, and a final stage which re-sets the circuit in readiness for the next card. Eighty output leads 44 are energized successively. Data sensed passes through gates 5-16 and cathode followers 59 to re-coding circuits, one 60 for the upper curtate and one 61 for the lower. The re-coding circuit 60 is controlled according to the code in use by the energization of one of five leads 90, 91, 92, 93, 95 from a corresponding trigger 101- 105. The code used may be changed from one column to the next, appropriate ones of trigger control leads 108-112 being energized through connections on plug board 113 as the lines 44 are pulsed in succession. The value of the O, B, A holes may vary in four codes from 1 to 11, and, additionally, in a fifth code the " A " hole represents the "- ve " symbol. Re-coding circuit, Fig. 5.-The upper curtate signals are applied on lines HA, HB, HO to the re-coder 60 which also receives a signal on one of the code lines 90-93 and 95. These lines are connected through diodes to particular ones of vertical lines 79 to 89 which are gated together in groups by diode gates 94, 97, 98, 99 and 100. The arrangement is such that when a read-out pulse appears on lead 42 the gates produce signals on combinations of leads CC1-CC8 which represent in pure binary code the value of the sensed data in the code being used. For example, in the second code (line 91 energized) an " A " perforation represents a value of 4. Gate 99, connected to output lead CC4 is enabled by signals on line 84 from line HA, line 85 from line 91 and line 86 from either of lines HA or 91. When the pulse appears on line 42 an output is obtained on line CC4. The presence of a signal on line HA when line 95 is energized produces the " - ve " signal on line 96. The data from the lower curtate 1-9 is re-coded in the normal way by diode connections from the lines H1-H9 to binary lines 63-66. These re-coded values appear on lines CC1-CC8 when the lower curtate read-out pulse appears on line 40. The count of two in counter 28 produces the lower curtate read-out pulse on line 40. Its trailing edge sets the appropriate one of code triggers 101-105 to energize one of the five code lines 90-93 and 95, and the count of three produces the read-out pulse for the upper curtate. The lower and upper curtate data therefore pass in turn to a store 114, entry being controlled by writing signals on leads 115 connected as desired by the plugboard 113 to the successively energized lines 44. Specification 881,909 also is referred to.