| 摘要 |
1,042,787. Electric calculating apparatus. BELL PUNCH CO. Ltd. March 16, 1965 [March 21, 1964], No. 10977/65. Divided out of 1,042,785. Heading G4A. In an electric calculating machine wherein a dividend with a decimal point is set in a register and a divisor with a decimal point is set on a keyboard, the decimal point of the quotient calculated in the register is automatically positioned. According to a first method of entering the dividend into the register, the digits are entered on the keyboard and the required decimal point position keys DK (Fig. 3, not shown), depressed. Strings of pulses are produced to enter the digits in the register counters and the decimal point is stepped one position in a counter DC during the entry of each digit until the actuated decimal point key DK is encountered which renders an NPN transistor TR conductive, thus closing a gate DG6 feeding pulses P6 to the ring counter DC, to prevent further stepping of the decimal point. The decimal point position is indicated by a glowing neon lamp L. According to a second method of entry into the register the digits are successively registered on a single bank of keys. During entry of the first digit a gate DG8 is energized to set a bi-stable device BD and consequently open a gate DG2 to step the ring counter DC from 0 to 10 and then from 10 to 9. During entry of the next digit the counter is stepped from 9 to 8 and in each successive cycle 11 pulses are applied leaving the lamp L8 illuminated. Successive digits are similarly entered until a decimal point key is depressed placing a negative potential on a terminal DP, thus leaving a gate DG3 closed and preventing further stepping of the decimal point. Division is performed by repeated subtraction of the divisor from the dividend until the remainder is negative and one add back as described in Specification 1,042,786. During the first add back since an output C+ is energized all inputs to a gate DG10 are energized, unsetting the bi-stable device BD, opening a gate DG5 and applying P6 pulses to the ring counter DC until the bi-stable device BD is set again due to closure of a gate DG7 when the transistor TR is rendered conductive by the actuated switch DK. The gate DG5 remains closed during all subsequent subtractions because T1 and t1 are not coincident and the decimal point is thus positioned. |
