US3745316A
Expired / Lapsed
US
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Computer checking system
Assignee: Allard Way Holdings Ltd
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Filing: 1971-12-13
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Granted: 1973-07-10
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Expires: 1991-12-13
Abstract
Abstract In a computer, a monitoring means for the detection of faults in operation comprises checksum forming means for forming concurrently with the performance of a program by the computer, a checksum of words read out from the computer memory in performance of the program, and means for comparing the checksum, at intervals, against predetermined values which the checksum should have at the times of comparison if the computer is operating correctly.
Inventors
- 👤 G Olah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:01
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/08; G06F11/10; G06F11/1008; G06F11/1076; G06F11/1004
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
187 words
A monitoring means for the detection of faults during performance of a program by a digital computer; said monitoring means comprising A. a processing unit, B. a memory in which arE stored words that define programs which can be performed by the computer under the control of the processing unit, and C. a data highway interconnecting the memory and the processing unit and onto which words are read-out from the memory in performance of programs by the computer, the monitoring means comprising: i. a register; ii. control means, responsive to signals on a data highway of the computer, for forming in the register concurrently with the performance of a program by the computer a sum of words read out from the computer memory onto the data highway in performance of that program; iii. read out means under the control of said control means for reading out the sum in the register at intervals; and iv. comparison means for comparing the output of the read-out means against predetermined values which the sum in the register should have at the times of read-out if the computer is operating correctly.
Claim 2
Dependent Claim
187 words
A monitoring means for the detection of faults during performance of a program by a digital computer; said monitoring means comprising A. a processing unit, B. a memory in which arE stored words that define programs which can be performed by the computer under the control of the processing unit, and C. a data highway interconnecting the memory and the processing unit and onto which words are read-out from the memory in performance of programs by the computer, the monitoring means comprising: i. a register; ii. control means, responsive to signals on a data highway of the computer, for forming in the register concurrently with the performance of a program by the computer a sum of words read out from the computer memory onto the data highway in performance of that program; iii. read out means under the control of said control means for reading out the sum in the register at intervals; and iv. comparison means for comparing the output of the read-out means against predetermined values which the sum in the register should have at the times of read-out if the computer is operating correctly.
Claim 3
Dependent Claim
72 words
A monitoring means according to claim 1 wherein the control means includes gate means via which the input of the register is connected with the data highway of the computer, and means for enabling the gate means in response to a first instruction word on the data highway and disabling the gates in response to a second instruction word on the data highway, whereby selected words only are entered in the register.
Claim 4
Dependent Claim
56 words
A monitoring means according to claim 2 wherein the read-out means includes further gate means via which the output of the register is connected with the comparison means, and the control means additionally includes means for enabling the further gate means and clearing the register in response to a third instruction word on the data highway.
Claim 5
Dependent Claim
65 words
A monitoring means according to claim 1 wherein the control means includes means responsive to an instruction word on the data highway for inserting a correction value in the sum in the register when the computer program sequence includes a branch such that the sum in the register when the computer program reaches a point beyond the branch is the same whichever branch is followed.
Claim 6
Dependent Claim
71 words
A monitoring means according to claim 1 wherein the control means includes means responsive to an instruction word on the data highway for inserting a correction value in the sum in the register when the program sequence includes a loop back such that the sum in the register when the computer program reaches a point beyond the loop is the same however many times the program sequence passes round the loop.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |