Patent GB-781389-A (GB)
Title: Data comparator
IPC: G06F7/02
Filed: 1955-03-25
Abstract: 781,389. Statistical apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 25,1955 [March 29, 1954], No. 8740/55. Addition to 779,030. Class 106 (1). Passing errors.-A data comparing device for use in card sorting apparatus similar to that described in the parent Specification with reference to Specification 523,652 comprises first means for comparing two multi-order data groups (e.g. the primary and secondary numbers shown in Fig. 2a) in a first relationship so as to detect corresponding orders having unmatched data and means operative for shifting the orders of data from said first relationship to a second relationship (as shown in Fig. 2b) in response to the detection of unmatched data in a predetermined number of orders corresponding in said first relationship. Second comparing means are provided for the groups in the second relationship and where unmatched orders are again detected, to shift the orders of data from the second relationship to a third relationship (Fig. 2c) in which the groups are compared again. Detection of unmatched orders in the third relationship by a third comparing means causes the orders of data to be returned to the original position. As can be seen, Fig. 2b represents a shift of the secondary data group one place to the left, and Fig. 2c represents a shift of two places to the right from the position of Fig. 2b. The fourth shift is a shift of one place to the left and returns the secondary data group to its original position as shown in Fig. 2a. The operation of the device is diagrammatically shown in Fig. 2a. The primary and secondary data are entered into register, the secondary data being entered into a shifting register 120 by means of comparator 121, the data in each position of the secondary data group is compared with each position in the primary data group. Unmatched data is detected in positions 3 and 4 and this causes the secondary data in each position to be entered into storage devices S, and from the storage devices, to be returned to the register in a position displaced one order to the left. A second comparison is then made in which each primary data order is compared with what was previously the secondary data in a position one order to the right (Fig. 2b). The detection of unmatched data in positions 4 and 5 causes the data of the secondary data group to be shifted two places to the right (Fig. 2c) and a third comparison made in which each primary data order is compared with what was originally the secondary data in a position one order to the left. The secondary data is then shifted back to original position and a fourth comparison is made. If the difference between the primary and secondary groups is the result of certain specified errors the comparisons in the three order positions outlined above will cause the data groups to be passed as matched. The specified errors are the same as those described in the parent Specification and are a " cross compare" error (e.g. Fig. 3, position 4), a " transposition of orders " error (e.g. Fig. 4a, positions 3 and 4), a " right-offset " error (e.g. Fig. 5a, positions 3, 4 and 5) and a " left-offset " error (e.g. Fig. 6a, positions 4, 5 and 6). Primary and secondary sensing brushes for each position are associated with groups of primary and secondary code relays, e.g. for position 1 primary code relays R1-R4 and secondary code relays R5-R8, some of which are picked according to the data sensed by the brushes as described in the parent Specification. These groups of primary and secondary code relays have contacts connected in comparing circuits as shown in Fig. 9c so that the data entered into the group of primary relays for each position is compared with the data entered into the corresponding group of secondary relays. These groups are R1-R8, R25-R32, R33-R40, R41-R48, R49-R56 and R57-R64. These groups of comparing relay contacts are repeated three times in Fig. 9c to provide three categories corresponding respectively to the cross-compare, right-offset and left-offset comparison. In Fig. 9e the units 20- 25 are " intermediate " storage units and correspond to the code relay groups for the secondary data positions 2, 3, 4, 5, 6, 1. When relays R90 or R106 pick, the appropriate relays R91- R94 in each unit are picked according to the data in secondary code relays R29-R32 &c. The units 32 to 37 are similarly intermediate storage units corresponding to secondary data positions 5, 6, 1, 2, 3, 4. When relay R98 picks-up the appropriate relays R99-R102 pick-up so as to store the data in the code relays R53-R56 &c. Units 26-31 are the storage units proper and second hold coils H2 of the relay groups R5-R8 &c, are connected so as to be energized by either relays R91 or R99 &c., in the units 20 and 32 respectively. Data entered in intermediate storage units 20- 25 is, upon energization of any of relays R95, R103, R107, entered into the corresponding storage units 26-31. This means that the data previously in code relay group R29-R32 of secondary position 2 is impressed upon the second hold coils H2 of the code relays R5-R8 corresponding to, secondary position 1. The first hold coils are de-energized and the relays pick according to the energization of the second hold coils. By this means the code relays of each position are picked according to the data of the position offset one order to the left. When relay R98 picks the data in units 32-37 is entered into units 26-31 and this causes the code relays R1-R4 &c. of each position to be picked up in accordance with the data in posi. tions displaced one order to the right. These operations therefore constitute a shift of the secondary data first one place to the left, then two places to the right and a third shift of one place to the left brings the secondary data back to the original position. Cross-compare errors.-Such an error, e.g. as shown in Fig. 3, is passed as matched by the circuit of Fig. 9f. An impulse applied to plug 101 picks relay R86 so that voltage from line 66 is applied to line 104 and connected through the coils of relay R87 and of a slow-to-operate relay R88. Relay R87 operates multiple contacts R87-1 to R87-6, Fig. 9c, connecting all the compare circuits to corresponding check relays R9-R14. Since positions 1, 2, 3, 5, 6 in Fig. 3 are matched relays R9, R10, R11, R13, R14 pick and a circuit is established in Fig. 9f from line 104 contacts R96-2 n/c, R88-1 n/o, R9-1 n/o, R10-1 n/o, R11-1 n/o, R12-1 n/c, R13-2 n/o, R14-2 n/o to plug 102 so that the data groups are passed as matched. The circuit of Fig. 9f passes one cross-compare error. Right-offset errors.-As shown in Fig. 5a equal data is present only in positions 1, 2, 3 so that check relays R9, R10, R11 pick-up. A circuit is therefore established in Fig. 9f through normally open contacts of relays R9, RIO, R11 to coil of relay R73LP which is a relay of the kind latching in the picked state and called a " latch-pick " relay. These relays R70LPR74LP are tripped by trip coils R70LTR74LT, Fig. 9d, when relay R111 or R112 are picked. When any of relays R70LP-R74LP is picked, relay R90 is energized and a slow-tooperate relay R89 picks later to de-energize it again after a short interval. As described above the energization of relay R90 causes the secondary data to be shifted, as far as the code relays are concerned one position to the left as shown in Fig. 5b. Also relay R95 picks relay R96 (Fig. 9d) so that relay R87 (Fig. 9f) is deenergized. This causes the contacts R87-1 to R87-6, Fig. 9c, to open and contacts R96-1 to R96-6 to close so that a comparison is made in the second category of code relay circuit 9c controlling check relays R15-R20. Since in Fig. 5b data is matched in positions 3, 4 and 5, check relays R17, R18 and R19 are picked. Voltage from line 104, Fig. 9f, therefore passes through a circuit as follows:-contacts R89-2 n/o, R73-1 n/o, R18-1 n/o, R19-1 n/o to " equal output " line 102 so that the data groups are passed as matched. Left-offset errors.-Such an error is shown in Fig. 6a arising from the omission of one of double letters. The left-offset error is only passed as matched in such a case as this, i.e. when the omission is one of a double letter. Cross-compare of the data in Fig. 6a detects matched orders in positions 1, 2, 3 and unmatched orders in positions 4, 5, 6, and so picks check relays R9, R10, R11. The circuit of Fig. 9f accordingly energizes relay R73LP when relay R86 is picked as described above. Relay R73LP causes the data orders to be shifted one place to the left as shown in Fig. 6b. There are, in this relationship, no positions with matched data and accordingly none of check relays R15- R20 is picked. Therefore, upon relay R89 picking a circuit is established in Fig. 9f from line 104 contacts R89-2 n/o, R73-1 n/o, R18-1 n/c, relay R78 to the opposite line. The series of relays R75-R79 are also " latch-pick " relays and are tripped by coils R75LT-R79LT, Fig. 9d, energized through contacts of relays R111 or R112. Any one of this series of relays, as shown in Fig. 9d, causes relay R98 and slow-tooperate relay R97 to pick, the latter de-energizing the former again after a short interval. Relay R98 causes the secondary data of each position to be entered into the intermediate storage units 32-37 and when relay R98 picks relay R103 (Fig. 9d) this data is entered into the groups of code relays R5-R8 &c. in the order shown in Fig. 6c. Relay R103 picks relay R104 to close contacts R104-1 to R104-2 so as to compare the Fig. 6c data orders in the third category of code relay groups in Fig. 9f governing check relays R21-R24, R65, R66. Matched orders are detected in positions 4, 5, 6 and check relays R24, R65, R66 are accordingly picked. A circuit is therefore established in Fig. 9f from line 104 through contacts R97-7 n/o, R78-1 n/o, R24-1 n/o, R65-1 n/o, R66-1 n/o to equal output line 102. These unmatched groups of data are therefore passed as mat