| 摘要 |
1,172,845. Electronic keyboard calculators; multiplication. BELL PUNCH CO. Ltd. 3 Jan., 1967 [3 Jan., 1966; 31 March, 1966], Nos 386/67 and 387/67. Divided out of 1,172,842 and 1,172,843. Addition to 1,042,785. Heading G4A. A calculating machine having a keyboard with a single order of digit keys and at least two registers each comprising a plurality of electric pulse-operated counting devices into which numbers entered from the keyboard may perform multiplication calculations involving numbers in two of said registers, the product being developed in one of said two registers. As described, numbers are entered from a keyboard 11 into a visual register 20 associated with number display tubes (Fig. 1, not shown) and may be transferred from there into one or other of two store registers 22, 23, the register comprising decade pulse counters. For multiplication, the multiplicand is in store register 22 or 23 and the multiplier in visual register 20. The tens complement of the digit in stage R3 of the visual register 20 is first fed into a buffer counter 35 and stages R1-R3 cleared. Pulses corresponding to the digits in stages r12 and r11 of the store register are then fed into stages R2 and R1 of the visual register a number of times equal to the original digit in R3 (as determined by buffer counter 35 which is stepped on each time until it reaches zero state); any overflow being stored in the stage R3. The complement of the contents of stage R4 is then fed into buffer counter 35 and pulses corresponding to stages r12-r10 are fed into stages R3-R1 with R4 storing any overflow. This process is repeated for all of the stages R3-R12. Gates and timing circuits for controlling these operations are shown and are described in the Specification. Control of the stages to which the various pulses are fed at each phase of the multiplication is achieved by the slipping of one timing circuit 18 with respect to another 15, each timing circuit comprising a multi-cathode counting circuit (Fig. 2, not shown). |
