GB1293376A - Improvements in or relating to calculating machines - Google Patents
Improvements in or relating to calculating machinesInfo
- Publication number
- GB1293376A GB1293376A GB3365969A GB3365969A GB1293376A GB 1293376 A GB1293376 A GB 1293376A GB 3365969 A GB3365969 A GB 3365969A GB 3365969 A GB3365969 A GB 3365969A GB 1293376 A GB1293376 A GB 1293376A
- Authority
- GB
- United Kingdom
- Prior art keywords
- register
- place
- counter
- rounding
- outputs
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F7/00—Methods or arrangements for processing data by operating upon the order or content of the data handled
- G06F7/38—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation
- G06F7/48—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation using non-contact-making devices, e.g. tube, solid state device; using unspecified devices
- G06F7/491—Computations with decimal numbers radix 12 or 20.
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F15/00—Digital computers in general; Data processing equipment in general
- G06F15/02—Digital computers in general; Data processing equipment in general manually operated with input through keyboard and computation using a built-in program, e.g. pocket calculators
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F7/00—Methods or arrangements for processing data by operating upon the order or content of the data handled
- G06F7/38—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation
- G06F7/48—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation using non-contact-making devices, e.g. tube, solid state device; using unspecified devices
- G06F7/499—Denomination or exception handling, e.g. rounding or overflow
- G06F7/49942—Significance control
- G06F7/49947—Rounding
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Computing Systems (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Computer Hardware Design (AREA)
- Calculators And Similar Devices (AREA)
Abstract
1293376 Rounding off BELL PUNCH CO Ltd 3 July 1970 [3 July 1969] 33659/69 Heading G4A A digital electric calculator includes a means for rounding off numbers stored in a register by adding 5 into the decimal place below the last such place to be retained in the rounded off number, adding in any resulting carry, and clearing all the non-required stages to zero. Provision is made for shifting the answer, which may be displayed on a set of digit indicating tubes, one place to the right if any carry ripples through to the most significant digit of the number. The number of places to which rounding is to be made can be varied by connecting the corresponding number of gates to a counter so that depression of a rounding key feeds the corresponding number of pulses to a counter. Two further counters providing sequential outputs on a number of leads equal to the number of stages in the register holding the number to be rounded are provided, the number of pulses stored in the first counter causing the outputs of the further counters to be relatively displaced. The outputs of these two counters, together with shift pulses gated to the register each time the counter outputs change control the rounding. The register contents are circulated until the counter outputs indicate that the most significant digit to be cleared is in a register stage connected to an adder. A factor of five is then added to that stage and any carry resulting from the addition is propagated until the most significant digit of the number has been processed. When the register is circulated one more place the counter outputs initiate clearing of the portion of the number not required by causing a circuit to pulse all the non-required digits to zero. During the carry propagation an extra shift one place to the right is initiated if an additional place is created by carry ripple through.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3365969A GB1293376A (en) | 1969-07-03 | 1969-07-03 | Improvements in or relating to calculating machines |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3365969A GB1293376A (en) | 1969-07-03 | 1969-07-03 | Improvements in or relating to calculating machines |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1293376A true GB1293376A (en) | 1972-10-18 |
Family
ID=10355767
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3365969A Expired GB1293376A (en) | 1969-07-03 | 1969-07-03 | Improvements in or relating to calculating machines |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1293376A (en) |
-
1969
- 1969-07-03 GB GB3365969A patent/GB1293376A/en not_active Expired
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PLE | Entries relating assignments, transmissions, licences in the register of patents | ||
PLNP | Patent lapsed through nonpayment of renewal fees |