740,656. Statistical apparatus. BRITISH TABULATING MACHINE CO., Ltd. Aug. 28, 1953, No. 23824/53. Class 106 (1). Apparatus for checking the corrections of sensed data recorded in a code employing a fixed number of code components for all characters comprises sensing means to provide code component impulses, and timing impulses, separate counting means to count the code component impulses and the timing impulses, means controlled jointly by the code component impulses and timing impulses for registering the coded data, means for subsequently reading out the registered data and means for making the read-out means effective only if the counting means has counted the predetermined numbers of code component and timing impulses. A cheque 1 having data recorded on it by small punched holes 2 is shown in Fig. 1. There are five columnar recording positions corresponding to the five possible code components A to E and five rows designated U to TT for recording a five-digit number. The holes shown represent the number 51049, the coding for the digits is set out below: A timing hole 3 is punched in the cheque 1 at a fixed distance from the data punchings. This hole is used to generate five timing impulses one of which will occur as each data position in a row of data holes is being sensed, so that only data impulses coinciding with a timing impulse are effective. A pinhole 4, for example, which is not located in a data position would not be registered as a data component. The count of the data code components prevents a pinhole, for instance hole 5 located in the D component position, being read for a code component. When the row TT is being sensed three impulses would be registered due to two correct holes 2 and the pinhole 5. This count indicates that imperfections in the cheque are affecting the sensing and can be used to control feeding of the cheque to a reject pocket. The timing hole 3 in the cheque is sensed by a photo-cell 20, Fig. 7, in a housing 21, Fig. 2. A lamp is mounted in a housing 23 and a slit allows the lamp to illuminate five holes 25, Fig. 3, in a plate 26 over which the cheque passes. The data holes are sensed by a photo-cell 33 enclosed in a housing 27 and located above a second group of five holes 31, Fig. 3, in the plate 26. These holes are illuminated by a lamp in a housing 29. A slide 32 is mounted between the housing 29 and plate 26, and is provided with a single hole to enable any one of the five holes to be manually selected to control sorting. The selection of sorting shoot blades 10 is controlled by four selector magnets 34, 35, 36, 37, Fig. 4, which correspond to the code components A, B, C, D. There are ten selector blades 43 which operate the shoot blades to open a path for the cheque by passing upwards through holes in the shoot blades until a blade without a hole is reached, the shoot blades each have a decreasing number of holes towards the top, the topmost blade having none. When the desired shoot blade has been raised the selector blade 43 must be withdrawn to allow passage of the cheque. To enable this to be done the raised shoot blades are held up by cam-operated grippers 57, 58, which close at the required time under the control of cam follower 61 and cam 63, and grip the raised shoot blades. This method of operating the shoot blades is necessary to enable the cheques which are not as rigid as normal statistical record cards to pass between the selected blades. Operation.-Before feeding of cheques commences the slides 32, Fig. 3, is set to select one of the rows of holes on the cheque to control sorting. When a cheque is fed through the sensing station the leading edge of the cheque will cut off the light from the data-sensing photo-cell 33. The resultant pulse is fed to a conventional pentode amplifying stage V7 via a cathode follower V6. The negative pulse from this valve is fed to the right-hand side of the double triode V3, the signal is fed via a rectifier 73 which is biased to provide a threshold. The positive pulse from V3 raises the trigger electrode of a gas discharge valve V5 sufficiently to fire it, thus energizing relay R1 in its cathode circuit. The output of the pentode V7 is also fed to the grid of the left-hand half of the double triode V8. The output of the left-hand side of V8 is differentiated by a condenser 95 and resistor 96 into the left-hand half of V9. The output pulse is again differentiated by a condenser 97 and resistor 98. The positive pulse is amplified by the right-hand half of V9 and appears as a negative pulse at the anode which is fed by a line 99 to a sorting count multicathode gas valve V8, Fig. 7a. The output of the left-hand half of V8 is also fed to the grid of the right-hand half of V8 through biased rectifier 100. The output of right-hand half of V8 is fed to V10 and the output of this stage is fed via line 122 to the trigger electrodes of four gas trigger valves V12, V13, V14 and V15. The timing impulses generated by photo-cell 20 are shaped and amplified in a similar manner before being applied to the multi-cathode gas valve V11, Fig. 7a. The method of operation of valve VII and V18 is well known and is such that the application of pulses to a trigger electrode causes the discharge to move successively along the cathodes. The extreme left-hand cathode of each of the tubes V11 and V18 is connected via cam contacts to ground via a resistor and condenser to enable the cam-controlled contacts C2, C3 to reset the tubes after each cheque has been sensed. If a code component is sensed at the same instant as the timing hole, then a pulse will be applied to the trigger electrodes of the valves V12 to V15 coincidentally with the increase of potential of the trigger electrodes. Thus the combined effect of the pulse and the priming voltage is sufficient to fire V12 whilst V13, V14 and V15 which are not primed remain non-conducting. The firing of V12 energizes a relay R2 in the cathode circuit. The contacts of this relay control subsequent energization of the selector magnet 34 which corresponds to code component A. Thus the data read from the cheque is temporarily registered on valves V12 to V15. The sixth cathode of valve V11 is connected to the trigger electrode of a gas valve V16, the circuit constants are so chosen that the voltage rise of the cathode when it carries the discharge is sufficient to fire V16 but only after the discharge has rested on the sixth cathode for some time. If the photo-cell 20 senses six holes due to a flaw in the cheque then the discharge will step along to the seventh cathode before the voltage of the trigger electrode has risen sufficiently to fire V16. If the count is short the discharge will not reach the sixth cathode and again V16 will not fire. The valve V18 receives a pulse via line 99 each time a code component is sensed, so that the discharge should rest on the third cathode from the left at the end of the sensing operation. This cathode controls the firing of the gas valve V17 which will thus only be fired if two components have been counted.. If both valves V11 and V18 register correct counts then the trigger valves V16 and V17 will conduct and energize relays R6 and R7 in their cathode circuits, these relays close their contacts R6a and R7a, Fig. 8, to complete circuits between supply lines 108 and 109 for energizing two of the four selector magnets through contacts R2a and R5a. Thus the sensed data is held registered at V12 to V15 until it is determined that both counts are correct, and only then is it read out to the selector magnets. If the count for either is incorrect then the data is not read out and none of the selector magnets is energized and the cheque passes over the shoot blades to the reject pocket. Specifications 242,654, [Class 106 (i)], and 718,066, [Group XVI], are referred to.