Patent GB-1366876-A (GB)
Title: Computing apparatus
IPC: G09B23/04
Filed: 1970-11-11
Abstract: 1366876 Binary calculator; binary arithmetic teaching appliance P R V YOUNGMAN 10 Nov 1971 [11 Nov 1970] 53755/70 Headings G4B and G5G A device, for calculating in the binary system and which may be for educational purposes, includes pivoted bi-stable members on which binary numbers can be set up, guides for directing elements (e.g. balls moving under gravity) past the members to interact therewith, the guiding of the elements being dependent upon the condition of at least some of the members, and further members actuatable by the guided elements to indicate the answer to the binary calculation. The device shown includes three sets of T- shaped bi-stable levers 16, 116, 216. Each lever can be set either in the position shown, wherein one side of the head of the T points towards the symbol "0" on an associated scale, or in a second position, wherein the same side of the head of the T points towards symbol "1". Two binary numbers to be added together, subtracted one from the other, multiplied or divided one into the other are manually set up on sets 16 and 116. Pins from a store 38 are inserted in selected ones of holes 19, 24, 25, 28, 29 and 36 to determine which of the four functions is to be carried out on the numbers. Balls (not shown) are then introduced one after another at entrance channel 2 and roll under the influence of gravity, through the device, along various paths determined by the selected pins and the levers 16, 116, the balls tripping the levers as they traverse their paths until finally an inhibit lever 34 is tripped, at which time the result of the calculation is registered by levers 216. Addition.-Pins are inserted in holes 24, 25, 36 and 19. The two numbers to be added are set up in the sets of lever 16, 116. An arm 18 pivotal with each lever 16 but angularly adjustable relative thereto is adjusted so that a depending portion at its free end abuts a ridge 11 to the right or left of the respective lever pivot, depending on whether the lever is in its "0" or "1" position. Surfaces 17 of those levers 16 set to "1" engage notches in a bar 12 to prevent movement of the bar to the left. The first two entered balls are halted by a ridge 8 and stored at 3. The third ball rolls along channel 6, is deflected by bar 12 into channel 10 and changes the position of the first lever 16. If the latter is at "0", the ball rolls on the upper side of the stem of the T to abut the head and pivot the lever to "1". The ball then moves on to the second lever. If the first lever was at "1", then the ball rolls along the lower side of the stem of the T to abut the head and pivot the lever to "0" and then rolls along channel 10a. Each ball thus resets n levers where the nth lever is the first one contacted by the ball which reads "1" before resetting. In this way each ball reduces the number stored in levers 16 by one. After co-operating with lever 16, each ball rolls along channel 10a, abuts the pin in hole 24 to pivot bar 22 thus shifting a rod 26 to the right to dislodge the first of the two balls stored at 3. The dislodged ball adds one to the number stored in levers 216. When all levers 16 have been reset to "0", levers 216 thus hold the number originally held by levers 16. Also bar 12 is free to move to the left when abutted by the next ball which therefore engages pin 15 and is deflected into channel 9a by pin 19. It then abuts the pin in hole 25 to move rod 26 and dislodge another counting ball from 3 to levers 216. It then reduces by one the number stored in levers 116. When the number stored in levers 116 has been reduced to 0001, bar 112 is free to move to the left because pin 36 prevents the surface 117 of the first lever engaging the notch in the bar. Consequently, the next ball shifts bar 112 to the left, abuts pin 115 and is diverted thereby into channel 109 to trip the inhibit lever 34, the latter giving an indication that the calculation is complete and blocking further action of bar 22 and rod 26. If further balls are entered, the blocked rod 26 cannot dislodge further counting balls to levers 216, which continue to store the sum. Subtraction.-Pins are inserted in holes 29, 25, 36, 19. A first group of balls resets levers 16 to "0" and subtracts the number originally set up in 16 from that originally set up in 116. A second group of balls resets 116 to "0" and releases a corresponding number of counting balls to 216. Multiplication.-Pins are inserted in 24 and 36. A first group of balls resets to "0" levers 16 and releases a correponding number of counting  balls to 216. The next ball rolls down channel 96 (no pin in hole 19) to impinge on the arms 18 of those levers 16 originally set at "1", thus to reset the original number back into 16, and then decreases the number held in 116 by one. This process is repeated until 116 is cleared. Division.-Pins are inserted at 25, 28, 29. The number stored in 16 is cleared and subtracted from 116. The next ball resets the number originally held back into 16 and releases a counting ball to 216. This subtraction is then repeated until 116 is cleared.