920,676. Statistical apparatus. NATIONAL CASH REGISTER CO. Oct. 25, 1961 [Dec. 15, 1960], No. 38159/61. Class 106 (1). A data processing system for processing a group of accounts, in which data sensed from first and second kinds of record media is automatically entered into an accounting- machine for the formation of new balances on the first record medium which bears an old balance and control data, the second record media bearing posting data and control data, includes a comparison device for comparing the control data on the two kinds of record media, a pair of totalizers, and a selecting device for the totalizers so controlled by the comparison device that one totalizer is selected to receive old balances and posting data when agreement of the compared control data is established and the other totalizer is selected to receive only old balances when disagreement of the control data is established. Selective engagement of totalizer lines 20, 22 with the differential actuators (not shown) is controlled by rotatable selecting plates 26 and 28, plate 28 being located behind plate 26, which are mounted on a shaft 32 and which are provided with a plurality of notches which are sensed by pawls 67, 69, respectively, so constructed that the left and right ends of pawl 67 senses only the notched on plates 28 and 26, respectively, whereas the right end of pawl 69 senses the notches on plate 28 and the left end senses the notches on both plates. Plate 26 is pivoted clockwise by energization of a solenoid L20, Fig. 8, which occurs only when an inactive account is being processed, a spring, not shown, being provided to return plate 26 to its initial position when solenoid L20 is de-energized. Plate 28 is set in one or other of two positions according to whether the balance picked up from a ledger card is a minus of plus balance. Pawls 67, 69 are pivoted at 107 and 109 to levers 102, 104, respectively, which are pivoted at 103, 105 to bell-cranks 106, 108 free on fixed shafts 110, 112. Also connected to pivot 105 is a link 111 pivoted at its other end to a cam follower 113, free on a shaft 115 and having a roller 117 which rides in a raceway 119 in a cam 66 which is fixed to a main drive-shaft 64. Cams 68, 70 also fixed to shaft 64, co-operate with rollers 72, 74 on a bell-crank 76 rotatably mounted on a fixed shaft 78 and pivoted at one end to a link 80 having upper and lower notches 82, 84 engageable with pins 86, 88 on a spider 90, and having a slot 91 in which rides a roller 93 which positions link 80 so that notch 82 or 84 engages pin 86 or 88, respectively, when the machine is to perform " add " or " reset " transactions, respectively. Spider 90, rotatably mounted on shaft 32, has a number of hooks 92 arranged to co-operate with studs 94, 96 which ride in slots 120, 122 in a fixed plate 128 and which are fixed to links 98, 100, respectively, pivoted to levers 102, 104. Bell-cranks 106, 108 have bifurcated portions to receive the ends of two arms of a lever 114 rotatably mounted on shaft 32. When can 66 is rotated, link 111 moves upwardly to rotate bell-cranks 106, 108 and lever 114 and thereby move pawls 67, 69 towards plates 26, 28. When an active account is being processed, the left and right ends of pawl 67 engage high portions of the peripheries of plates 28 and 26, respectively, whereas the left and right ends of pawl 69 engage a notch and high portion, respectively, in plates 26, 28 and plate 28. Pawl 67 is held against inward movement and pivot point 107 acts as a fulcrum for lever 102 which thereby moves stud 94 of link 98 into engagement with hook 92 on spider 90, whereas pawl 69 is not held against inward movement and so stud 96 fails to engage hook 92 on the spider. When this movement of levers 102, 104 is completed, cam 70 rotates bell-crank 76 and spider 90 clockwise pulling with them only stud 94. This movement of link 98 causes the totalizers of line 20 to engage differential actuators. However, in the case of an inactive account when plate 26 has been rocked by energization of solenoid L20 totalizer line 22 is engaged with the differential actuators. The totalizers of lines 20 or 22 are disengaged from the actuators by counter-clockwise movement of spider 90 under the control of cam 68, the disengaging movement commencing and ending after 320 and 360 degrees, respectively, of rotation of drive-shaft 64. When the machine has been set to accomplish an automatic posting run and a trial balance, contacts ST206B1, Fig. 6, are closed and relay K274 is energized to open contacts K274BC2. When there is no entry on the tape relating to a particular account on a ledger card, a first or comparator relay K318, not shown, does not energize and contacts K318A5 remain open to prevent energization of a second relay K273. The trip coils L20, or initiation control device, of the tape reader are therefore not energized and operation of the tape reader is prevented. The machine is provided with a printer cam line and an auxiliary cam line. At the start of the machine operation the latter rotates through 180 degrees and stops. The other cam line commences rotation, after the first has rotated through 170 degrees, and after rotating through 155 degrees, the printer cam line rotates a further 180 degrees. At 145 degrees of rotation of the auxiliary cam line, contacts SC919 close and pawl check relay K309 is energized. Contacts K309A1 are closed and a holding circuit for relay K309 is completed until contacts SC15A1 are opened after 165 degrees of rotation of the auxiliary cam line. At 30 degrees of rotation of the printer cam line, contacts SC955 close and since contacts K274A14 have been closed, solenoid L20 is energized, causing totalizer line 22 to be engaged with the actuators and the balance sensed from the ledger card is placed directly in the trial balance total in line 22. As both cam lines rotate to home position, contacts SC921A1 and SC941A1 close and complete a circuit for relay K302, contacts K308AC4 having been closed, energization of which prepares the machine to accept another card from the ledger card feeder. Specification 895,369 is referred to.