GB816222A - Improvements in counting devices - Google Patents

Abstract

816,222. Counting-apparatus; statistical apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. Dec. 23, 1955 [Dec. 30,1954], No. 36930/55. Class 106 (1). A counting-apparatus comprises a plurality of bi-stable devices arranged to assume characteristic combinations of states, in which the combination representing any digit registered therein differs from that representing the complementary digit by the state of one particular device only, so that the digit registered may be changed to its complement by changing the state of said one device. In the first example a decimal counter comprises five relays 11-15, Fig. 1A, each having a latch and drop coils L and D respectively and being arranged in two parallel chains 15L, 11L, 13L, 13D, 11D and 15D, 12L, 14L, 14D, 12D. The entry to the counter is from punched cards and the programme determines whether a digit is to be entered into the counter in its true or complement form. If the digit is to be entered in its true form impulses are passed to the counting chain from the instant of sensing a hole until the tenth point,of a card cycle. Impulses one, two ... nine cause energization of the relay coils in the following sequency 11L, 12L, 13L, 14L, 15L, 14D, 13D, 12D, 11D and the coils 18L, 18D of a control relay are alternately energized to direct alternate impulses to the appropriate chain. If the digit is to be entered in its complementary form impulses are passed to the counting chain from the beginning of a card cycle until a hole is sensed: It can be seen from the above sequence of operation of the relay coils that the registration of a particular digit differs from the registration of its complement merely by the state of relay 15 so that conversion of a digit to its complement is effected by changing the state of relay 15. Transfer.-At point thirteen of a card cycle an impulse is admitted to the counting chains if the chains of the next lower order have passed through the registration " 9 to " 0." Read-out.-During a read-out cams 9-0, Fig. 1, generate impulses through points one ... ten of a card cycle. The state of a relay 25 determines whether the digit is to be read out in its true or complement form and the state of relay contacts 11d, 12d, 13d, 14d, 14e, 13e, 12e, 11e determine the number of impulses transmitted to the. read-out means. Zeroizing is effected by transmitting impulses until the relays 11-15 register zero. In another example six relays 71-76, Fig. 3A, are used, the coils 71L, 73L, 75L, 75D, 73D, 71D and 76L, 72L, 74L, 74D, 72D, 76D being disposed in two parallel chains as shown. This counter operates in the base twelve but by selectively shorting out relay 75, relays 74 and 75 or relays 71 to 75 the base can be altered to ten, eight or two. Transfer and reading out are effected as described above but zeroizing is effected by instantaneously setting the relays 71-76 to register zero.