US3735107A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coded decimal divider with pre-conditioning of divisor
Assignee: US Philips Corp
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Filing: 1972-01-26
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Granted: 1973-05-22
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Expires: 1992-01-26
Abstract
Abstract A calculating device for dividing decimal numbers according to the method of division without restoration of the remainder, comprising means for determining, prior to the start of the dividing process, whether the divisor digit present in the tetrade of the highest order less one of the divisor tetrade register (a 0 is present in the divisor tetrade of the highest order) is smaller than 5. If this is the case, these means produce a command for multiplying the dividend and the divisor, such that, said divisor digit becomes larger than or at least equal to 5. The said means provide a shift command during the dividing process, so as to shift the remainder present in the calculating unit over a number of digit tetrades of a higher order, this number being at least equal to one, in the dividend tetrade register, and for storing a corresponding number of quotient digits in the quotient digit tetrade(s) of the lowest order in the quotient tetrade register. The said number of digit tetrades is determined by the number, or number reduced by one, respectively, of zeros or nines of the remainder which preceeds the number <5 or > OR = 5, or > OR = 5 or <5, respectively. A modification of the device enables direct and automatic formation of the correct quotient digits.
Inventors
- 👤 D Bolt
- 👤 J Reitsma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:10
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/38; G06F7/48; G06F7/491; G06F7/4915; G06F7/4917; G06F7/498; G06F7/4983; G06F7/4985
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
288 words
A calculating device for dividing decimal numbers according to a method of division which does not restore a remainder, said device comprising a divisor tetrade register for storing divisor digits, the divisor digit of a highest order being a 0, a dividend tetrade register for storing dividend digits or, after a subtraction or an addition of a divisor, stores remainder digits, a quotient tetrade register for storing quotient digits, a calculating unit connected to the latter registers and a control unit connected to said calculating unit which supplies, if a dividend or a remainder is positive, a command to the calculating unit for performing a subtraction of contents of the divisor tetrade register from contents of the dividend tetrade register, or, if a remainder is negative, a command for performing an addition of the contents of the divisor tetrade register to the contents of the dividend tetrade register, means connected to said calculating unit for establishing, prior to the start of the dividing process, whether the divisor digit present in the tetrade of the highest order less one of the divisor tetrade register is smaller than 5, said means, if this is the case, supplying a command for multiplication of the dividend and the divisor by a given factor, such that after one or more multiplication operations, the said divisor digit is larger than, or at least equal to 5, and means connected to said calculating unit for supplying, if a remainder is <05 or > OR = 95, respectively, a shift command during the dividing process for shifting the remainder into a digit tetrade of a higher order and for shifting the associated quotient digit into the tetrade of a lowest order of the quotient tetrade register.
Claim 2
Dependent Claim
288 words
A calculating device for dividing decimal numbers according to a method of division which does not restore a remainder, said device comprising a divisor tetrade register for storing divisor digits, the divisor digit of a highest order being a 0, a dividend tetrade register for storing dividend digits or, after a subtraction or an addition of a divisor, stores remainder digits, a quotient tetrade register for storing quotient digits, a calculating unit connected to the latter registers and a control unit connected to said calculating unit which supplies, if a dividend or a remainder is positive, a command to the calculating unit for performing a subtraction of contents of the divisor tetrade register from contents of the dividend tetrade register, or, if a remainder is negative, a command for performing an addition of the contents of the divisor tetrade register to the contents of the dividend tetrade register, means connected to said calculating unit for establishing, prior to the start of the dividing process, whether the divisor digit present in the tetrade of the highest order less one of the divisor tetrade register is smaller than 5, said means, if this is the case, supplying a command for multiplication of the dividend and the divisor by a given factor, such that after one or more multiplication operations, the said divisor digit is larger than, or at least equal to 5, and means connected to said calculating unit for supplying, if a remainder is <05 or > OR = 95, respectively, a shift command during the dividing process for shifting the remainder into a digit tetrade of a higher order and for shifting the associated quotient digit into the tetrade of a lowest order of the quotient tetrade register.
Claim 3
Dependent Claim
166 words
A calculating device as claimed in claim 1, wherein said shift command serves for shifting a remainder formed in the calculating unit over a number of digit tetrades of a higher order in the dividend tetrade register, and for storing a corresponding number of associated quotient digits in the quotient digit tetrades of the lowest order of the quotient tetrade register, the maximum number of digit tetrades being equal to the number of digits of those digits of the highest order of the remainder, that containing a digit 0 followed by a digit smaller than 5, or containing a digit 9 followed by a digit which is larger than, or equal to 5, said maximum number of digit tetrades furthermore being equal to the number of digits of the digits of the highest order of the remainder reduced by one, containing a digit 0 followed by a digit larger than, or equal to 5, or containing a digit 9 followed by a digit smaller than 5.
Claim 4
Dependent Claim
131 words
A calculating device as claimed in claim 2, wherein the divisor tetrade register comprises an additional tetrade in the location whose order is one higher than the location of the divisor digit of the highest order (0), a digit 9 being permanently stored in said additional tetrade, the dividend tetrade register comprising an additional tetrade in the location whose order is one higher than the location of the dividend (remainder) digit of the highest order, a digit 0 being stored in the latter additional tetrade at the start of a division, the add or subtract operations, respectively, in the calculating unit, also involving contents of said additional tetrades, and automatically producing the correct quotient digit, said quotient digit being shifted into the quotient tetrade register in reaction to a shift command.
References Cited (Backward Citations)
US3234366A
Cited
US3578961A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |