Arithmetic system for use in electronic calculator

Claim 2

An arithmetic system for use in an electronic calculator including a keyboard provided with a plurality of numerical keys representing decimal digits zero through nine and a plurality of function keys including a constant calculation key and a clear key, said system comprising: first storing means for storing input signals fed from a suitable source, the contents of said first storing means being cleared from said first storing means only when said clear key is operated; second storing means for storing the contents of said first storing means, which has been transferred thereto, during a period in which a signal indicative of the depression of said constant calculation key is generated; gating means having one input terminal adapted to receive an output signal from said first storing means and another input terminal adapted to receive a signal from said keyboard representative of the depression of said constant calculation key, whereby said gating means can be triggered on for a certain period of time in response to the signal representative of the depression of said constant calculation key, to thereby permit the transfer of the contents of said first storing means to said second storing means; and arithmetic means for effecting an arithmetic operation in response to the contents of said first and second storing means, the output of said arithmetic means being connected to said first storing means for storing therein the result of said arithmetic operation.

Claim 3

An arithmetic system for use in an electronic calculator including a keyboard provided with a plurality of numerical keys representing decimal digits zero through nine and a plurality of function keys including a constant calculation key and a clear key, said system comprising: first storing means for storing input signal fed thereto; first gating means disposed between an output and input of said first storing means for permitting the circulation of the content of said first storing means; second storing means for storing the contents of said first storing means when said contents of said first storing means have been transferred thereto; second gating means having one input terminal adapted to receive an output signal from said first storing means and another input terminal adapted to receive a signal from said keyboard representative of the depression of said constant calculation key, whereby said second gating means can be triggered on for a certain period in response to the signal representative of the depression of said constant calculation key, to thereby permit the transfer of the contents of said first storing means to said second storing means; third gating means disposed between an output and input of said second storing means for permitting the circulation of the contents of said second storing means during a period in which a signal indicative of the depression of said constant calculation key is generated; and arithmetic means for effecting an arithmetic operation in response to the contents of said first and second storing means, the output of said arithmetic means being connected to said first storing means for storing therein the result of said arithmetic operation.

Claim 4

An arithmetic system for use in an electronic calculator including a keyboard provided with a plurality of numerical keys representing decimal digits zero through nine and a plurality of function keys including a constant calculation key and a clear key, said system comprising: first storing means for storing input signal fed thereto; first gating means disposed between an output and input of said first storing means for permitting the circulation of the content of said first storing means; second storing means for storing the contents of said first storing means when said contents of said first storing means have been transferred thereto; second gating means having one input terminal adapted to receive an output signal from said first storing means and another input terminal adapted to receive a signal from said keyboard representative of the depression of said constant calculation key, whereby said second gating means can be triggered on for a certain period in response to the signal representative of the depression of said constant calculation key, to thereby permit the transfer of the contents of said first storing means to said second storing means; third gating means disposed between an output and input of said second storing means for permitting the circulation of the contents of said second storing means during a period in which a signal indicative of the depression of said constant calculation key is generated; and arithmetic means for effecting an arithmetic operation in response to the contents of said first and second storing means, the output of said arithmetic means being connected to said first storing means for storing therein the result of said arithmetic operation.

Claim 5

In an electronic calculator including a keyboard provided with a plurality of numerical keys representing predeterminEd arithmetic digits and a plurality of functional keys, an arithmetic system for carrying out calculations in which a number may be repeatedly employed in calculations, comprising: an arithmetic unit for carrying out an arithmetic operation in response to instructional signals supplied by the depression of numerical and functional keys on said keyboard; first means, responsive to the depression of a predetermined one of said functional keys, for storing input signals representative of a number; second means, responsive to the depression of a functional key on said keyboard, for supplying the contents of said first means to said arithmetic unit for carrying out a calculation employing a number represented by signals stored in said first means; third means, responsive to the operation of said arithmetic unit, for storing signals representative of the operation of said arithmetic unit; and first gating means, connected between the output of said third means and the input of said first means, for enabling the transfer of the contents of said third means to said first means.

Claim 6

In an electronic calculator including a keyboard provided with a plurality of numerical keys representing predeterminEd arithmetic digits and a plurality of functional keys, an arithmetic system for carrying out calculations in which a number may be repeatedly employed in calculations, comprising: an arithmetic unit for carrying out an arithmetic operation in response to instructional signals supplied by the depression of numerical and functional keys on said keyboard; first means, responsive to the depression of a predetermined one of said functional keys, for storing input signals representative of a number; second means, responsive to the depression of a functional key on said keyboard, for supplying the contents of said first means to said arithmetic unit for carrying out a calculation employing a number represented by signals stored in said first means; third means, responsive to the operation of said arithmetic unit, for storing signals representative of the operation of said arithmetic unit; and first gating means, connected between the output of said third means and the input of said first means, for enabling the transfer of the contents of said third means to said first means.

Claim 7

An arithmetic system according to claim 3, further including fourth means, coupled to the output of said third means, for storing the contents thereof irrespective of the storage of the contents thereof by said first means.

Claim 8

An arithmetic system according to claim 3, further including second gating means connected between the output and input of said first means, for enabling the recirculation of the contents thereof.

Claim 9

An arithmetic system according to claim 4, further including third and fourth gating means connected to the input of said arithmetic unit and responsive to the output of said third and fourth means for supplying the signals stored therein to said arithmetic unit.

Claim 10

An arithmetic system according to claim 6, further including a encoder unit, coupled to the output of said numerical keys on said keyboard, for connecting the signals generated by the depression of said numerical keys into digital signals, to be gateably coupled to said arithmetic unit through an arithmetic input gate.

Claim 11

An arithmetic system according to claim 7, wherein said arithmetic unit comprises a full adder circuit and wherein each of said first, third and fourth means comprises a shift register capable of storing signals representing the output of said full adder circuit.

Claim 12

An arithmetic system according to claim 8, further including a circuit for generating a pulse having a duration at least equal to one word period connected between the predetermined one of said functional keys and said first gating means, for gating the contents of said third means to said first means.

Claim 13

An arithmetic system according to claim 6, wherein said third and fourth gating means include a terminal for receiving a clear signal for clearing the contents of said third and fourth means.

Claim 14

An arithmetic system according to claim 3, further including means for displaying the contents of said third means, so as to indicate the result of an operation of said arithmetic unit.

Claim 15

An arithmetic system according to claim 3, further including a circuit for generating a pulse having a duration at least equal to one word period connected between the predetermined one of said functional keys and said first gating means, for gating the contents of said third means to said first means.

Claim 16

An arithmetic system according to claim 12, wherein said third and fourth gating means include a terminal for receiving a clear signal for clearing the contents of said third and fourth means.