US3377624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Memory protection system
Assignee: International Business Machines Corp
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Filing: 1966-01-07
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Granted: 1968-04-09
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Expires: 1986-01-07
Abstract
No abstract record available.
Inventors
- 👤 Robert A Nelson
- 👤 Jr Ira T Ellis
- 👤 Lois M Haibt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:04
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/14; G06F12/1458; G06F12/1491
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
87 words
A MEMORY PROTECTION SYSTEM COMPRISING: FIRST MEANS FOR INDICATING WHETHER AN INSTRUCTION WHICH RESULTS IN SAID MEMORY BEING ACTED UPON IN A PREDETERMINED MANNER IS PRIVILEGED; SECOND MEANS FOR INDICATING WHETHER THE PORTION OF SAID MEMORY ACTED UPON IN SAID PREDETERMINED MANNER IS CONDITIONALLY PROTECTED; AND MEANS RESPONSIVE TO THE COMBINED OCCURRENCE OF AN INDICATION FROM SAID FIRST INDICATING MEANS THAT SAID INSTRUCTION IS NOT PRIVILEGED AND TO AN INDICATION FROM SAID SECOND INDICATING MEANS THAT SAID AREA OF MEMORY IS CONDITIONALLY PROTECTED FOR GENERATING AN INTERRUPT.
Claim 2
Dependent Claim
87 words
A MEMORY PROTECTION SYSTEM COMPRISING: FIRST MEANS FOR INDICATING WHETHER AN INSTRUCTION WHICH RESULTS IN SAID MEMORY BEING ACTED UPON IN A PREDETERMINED MANNER IS PRIVILEGED; SECOND MEANS FOR INDICATING WHETHER THE PORTION OF SAID MEMORY ACTED UPON IN SAID PREDETERMINED MANNER IS CONDITIONALLY PROTECTED; AND MEANS RESPONSIVE TO THE COMBINED OCCURRENCE OF AN INDICATION FROM SAID FIRST INDICATING MEANS THAT SAID INSTRUCTION IS NOT PRIVILEGED AND TO AN INDICATION FROM SAID SECOND INDICATING MEANS THAT SAID AREA OF MEMORY IS CONDITIONALLY PROTECTED FOR GENERATING AN INTERRUPT.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-04-09 | 1971-10-09 | 1972-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-09 | 1975-10-09 | 1976-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-09 | 1979-10-09 | 1980-04-09 | $7700.00 | Window Closed / Lapsed |