Electronic perpetual calendar

Claim 2

A calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, comprising: A. signal generating means for providing electronic input signals corresponding to the available span of year numbers and the twelve months of the year, said signal generating means including first and second pairs of decade counters, each with 10 decoded decimal outputs, connected so as to have each pair able to count from 0 to 99 to represent, in the one case a first two-digit number constituted by the thousands and hundreds digits of any selected year number, and in the other case a second two-digit number constituted by the tens and units digits of any selected year number, B. selector switch means settable to respective control positions to provide for the derivation, from said signal generating means, of specific input signals corresponding, for either type of calendar, to the number of the year desired or to the name of the month plus the number of the year desired, and C. logic circuit means responsive to said specific input signals for providing corresponding output signals, said logic circuit means including first and second counters arranged to divide said first number by 4 and by 7, respectively, said first counter being activatable only for a Gregorian calendar period display and said second counter being activatable only for a Julian calendar period display, a third counter arranged to divide said second number by 28, and a first memory having first and second address registers and 203 addresses at each of which is located a respective code number designating a respective one of the fourteen available yearly calendar periods, each of said first and second counters being connected to apply its respective output to said first address register only when that counter is activated, and said third counter being connected to apply its output to said second address register.

Claim 3

A calendar period selector circuit according to claim 1, wherein said selector switch means further comprises a calendar type selector switch arranged to enable said first counter for a Gregorian calendar period display only and to enable said second counter for a Julian calendar period display only.

Claim 4

A calendar period selector circuit according to claim 2, wherein said logic circuit means further comprises a second memory having third and fourth address registers and 168 addresses at each of which is located a respective code number designating a respective one of the twenty-eight available monthly calendar periods, the output connections of said first memory being arranged to apply the code number output of the latter either to a control circuit for a calendar period display system or to said third address register, a source of twelve binary number signals each corresponding to a respective one of the months of the year connected to said fourth address register, and wherein said selector switch means further comprises a month/year selector switch arranged either, if a monthly calendar period display is desired, to permit the application of the code number output of said first memory to said third address register jointly with the application of the output of said binary number signal source to said fourth address register for providing a monthly calendar period code number output from said second memory to be applied to said control circuit, or if a yearly calendar period display is desired, to permit the application of the yearly calendar period code number output of said first memory exclusively to said control circuit.

Claim 5

A calendar period selector circuit according to claim 3, wherein said logic circuit means further comprises a permanent register connected to apply an output, representing a fixed number other than any of the numbers available from said third counter, to said second address register for accessing the addresses of code numbers designating only century years, and gate means responsive, upon said calendar type selector switch being set for the Gregorian calendar, to signals from said second pair of decade counters corresponding to said second number being 00 for enabling said permanent register and concomitantly blocking the output of said third counter from said second address register.

Claim 6

A logic circuit module for use in a calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, said logic circuit module comprising: A. first and second electronic counters arranged, respectively, to receive electronic signal inputs corresponding to, and to divide by 4 and by 7, a first two-digit number constituted by the thousands and hundreds digits of any selected year number, said first counter being activatable only for a Gregorian calendar period display and said second counter being activatable only for a Julian calendar period display, B. a third counter arranged to receive electronic signal inputs corresponding to, and to divide by 28, a second two-digit number constituted by the tens and units digits of any selected year number, and C. a first memory having first and second address registers and 203 addresses at each of which is located a respective code number designating a respective one of the fourteen available yearly calendar periods, each of said first and second counters being connected to apply its respective output to said first address register only when that counter is activated, and said third counter being connected to apply its output to said second address register.

Claim 7

A logic circuit module for use in a calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, said logic circuit module comprising: A. first and second electronic counters arranged, respectively, to receive electronic signal inputs corresponding to, and to divide by 4 and by 7, a first two-digit number constituted by the thousands and hundreds digits of any selected year number, said first counter being activatable only for a Gregorian calendar period display and said second counter being activatable only for a Julian calendar period display, B. a third counter arranged to receive electronic signal inputs corresponding to, and to divide by 28, a second two-digit number constituted by the tens and units digits of any selected year number, and C. a first memory having first and second address registers and 203 addresses at each of which is located a respective code number designating a respective one of the fourteen available yearly calendar periods, each of said first and second counters being connected to apply its respective output to said first address register only when that counter is activated, and said third counter being connected to apply its output to said second address register.

Claim 8

A logic circuit module according to claim 5, further comprising a second memory having third and fourth address registers and 168 addresses at each of which is located a respective code number designating a respective one of the twenty-eight available monthly calendar periods, the output connections of said first memory being arranged to apply the code number output thereof either to a control circuit for a calendar period display system or to said third address register, and a source of twelve binary number signals each corresponding to a respective one of the months of the year connected to said fourth address register, whereby if a monthly calendar period display is desired, the code number output of said first memory is applied to said third address register jointly with the application of the output of said binary number signal source to said fourth address register for providing a monthly calendar period code number output from said second memory to be applied to said control circuit, or if a yearly calendar period display is desired, the code number output of said first memory is applied exclusively to said control circuit.

Claim 9

A logic circuit module according to claim 6, further comprising a permanent register connected to apply an output, representing a fixed number other than any of the numbers available from said third counter, to said second address register for accessing the addresses of code numbers designating only century years, and gate means responsive to signal inputs corresponding to said second number being 00 in a Gregorian calendar year for enabling said permanent register and concomitantly blocking the output of said third counter frOm said second address register.

Claim 10

A calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, comprising: A. signal generating means for providing electronic input signals corresponding to the available span of year numbers and the twelve months of the year, said signal generating means including first and second pairs of decade counters, each with 10 decoded decimal outputs, and a 14-bit counter connected so as to be able to count from 0 to 9,999 to represent any selected year number, B. selector switch means settable to respective control positions to provide for the derivation, from said signal generating means, of specific input signals corresponding for either type of calendar, to the number of the year desired or to the name of the month plus the number of the year desired, and C. logic circuit means responsive to said specific input signals for providing corresponding output signals, said logic circuit means including a first register for receiving electronic signal inputs corresponding to, and for retaining, any selected year number from the available span of year numbers and for providing a corresponding year number output, gate means connected with said counters and said first register for enabling said selected year number represented by corresponding electronic signal inputs from said signal generating means to be selectively placed into said first register, and electronic calculator means programmed to perform a series of mathematical operations to transform said year number outputs of said first register into respective code numbers each designating a respective one of the available calendar periods, said calculator means including a second register, three first division circuits operable for dividing by 4, by 100 and by 400, respectively, said first division circuits being connected between said first and second registers for sequentially receiving as identical inputs from said first register each year number output thereof and for individually providing both a quotient output as an input to said second register and an either zero or not-zero remainder output as a test of whether the year to be displayed is a leap year or not a leap year, all of said first division circuits being activatable for a Gregorian calendar period display and only that one of said first division circuits which divides by 4 being activatable for a Julian calendar period display, and a plurality of addition, subtraction and second division circuits operatively connected with said second register and operable in sequence for correspondingly modifying either a number which at the time of such operation is being placed into said second register or a number which at the time of such operation is already in said second register as the result of a prior operation of said circuits, said second register upon completion of all such operations providing said output signals.

Claim 11

A calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, comprising: A. signal generating means for providing electronic input signals corresponding to the available span of year numbers and the twelve months of the year, said signal generating means including first and second pairs of decade counters, each with 10 decoded decimal outputs, and a 14-bit counter connected so as to be able to count from 0 to 9,999 to represent any selected year number, B. selector switch means settable to respective control positions to provide for the derivation, from said signal generating means, of specific input signals corresponding for either type of calendar, to the number of the year desired or to the name of the month plus the number of the year desired, and C. logic circuit means responsive to said specific input signals for providing corresponding output signals, said logic circuit means including a first register for receiving electronic signal inputs corresponding to, and for retaining, any selected year number from the available span of year numbers and for providing a corresponding year number output, gate means connected with said counters and said first register for enabling said selected year number represented by corresponding electronic signal inputs from said signal generating means to be selectively placed into said first register, and electronic calculator means programmed to perform a series of mathematical operations to transform said year number outputs of said first register into respective code numbers each designating a respective one of the available calendar periods, said calculator means including a second register, three first division circuits operable for dividing by 4, by 100 and by 400, respectively, said first division circuits being connected between said first and second registers for sequentially receiving as identical inputs from said first register each year number output thereof and for individually providing both a quotient output as an input to said second register and an either zero or not-zero remainder output as a test of whether the year to be displayed is a leap year or not a leap year, all of said first division circuits being activatable for a Gregorian calendar period display and only that one of said first division circuits which divides by 4 being activatable for a Julian calendar period display, and a plurality of addition, subtraction and second division circuits operatively connected with said second register and operable in sequence for correspondingly modifying either a number which at the time of such operation is being placed into said second register or a number which at the time of such operation is already in said second register as the result of a prior operation of said circuits, said second register upon completion of all such operations providing said output signals.

Claim 12

A calendar period selector circuit according to claim 8, wherein said selector switch means further comprises a calendar type selector switch arranged to effect the activation of said first division circuits either for a Gregorian calendar period display only or for a Julian calendar period display only.

Claim 13

A logic circuit module for use in a calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, said logic circuit module comprising: A. a first register for receiving electronic signal inputs corresponding to, and for retaining, any selected year number from the available span of year numbers and for providing a corresponding year number output, and B. electronic calculator means programmed to perform a series of mathematical operations to transform said year number outputs of said first register into respective code numbers each designating a respective one of the available calendar periods, said calculator means including a second register, three first division circuits operable for dividing by 4, by 100 and by 400, respectively, said first division circuits being connected between said first and second registers for sequentially receiving as identical inputs from said first register each year number output thereof and for individually providing both a quotient output as an input to said second register and an either zero or notzero remainder output as a test of whether the year to be displayed is a leap year or not a leap year, all of said first division circuits being activatable for a Gregorian calendar period display and only that one of said first division circuits which divides by 4 being activatable for a Julian calendar period display, and a plurality of addition, subtraction and second division circuits operatively connected with said second register and operable in sequence for correspondingly modifying either a number which at the time of such operation is being placed into said second register or a number which at the time of such operation is already in said second register as the result of a prior operation of said circuits, said second register upon completion of all such operations providing output signals representing said code numbers.

Claim 14

A logic circuit module for use in a calendar period selector circuit for an electronic perpetual calendar intended for displaying selected yearly or monthly calendar periods for any year in a given span of years falling between the year 0 and the year 9,999 in either the Gregorian or the Julian calendar, said logic circuit module comprising: A. a first register for receiving electronic signal inputs corresponding to, and for retaining, any selected year number from the available span of year numbers and for providing a corresponding year number output, and B. electronic calculator means programmed to perform a series of mathematical operations to transform said year number outputs of said first register into respective code numbers each designating a respective one of the available calendar periods, said calculator means including a second register, three first division circuits operable for dividing by 4, by 100 and by 400, respectively, said first division circuits being connected between said first and second registers for sequentially receiving as identical inputs from said first register each year number output thereof and for individually providing both a quotient output as an input to said second register and an either zero or notzero remainder output as a test of whether the year to be displayed is a leap year or not a leap year, all of said first division circuits being activatable for a Gregorian calendar period display and only that one of said first division circuits which divides by 4 being activatable for a Julian calendar period display, and a plurality of addition, subtraction and second division circuits operatively connected with said second register and operable in sequence for correspondingly modifying either a number which at the time of such operation is being placed into said second register or a number which at the time of such operation is already in said second register as the result of a prior operation of said circuits, said second register upon completion of all such operations providing output signals representing said code numbers.