US3848262A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drum memory protect arrangement
Assignee: AG Communication Systems Corp
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Filing: 1973-04-06
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Granted: 1974-11-12
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Expires: 1993-04-06
Abstract
Abstract A drum memory system is described including the circuits and their system oriented relationship necessary to reduce the probability of destroying the data stored on a rotating magnetic drum due to common faults within the memory logic and linear write-read system. The problems associated with power supply failures, the most common faults, are treated.
Inventors
- 👤 R Belcastro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:05
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/002; G11; G11B; G11B5/00; G11B5/02; G11B5/09
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
160 words
In a rotating memory system having a rotating memory and having write and read head means, first power means for driving the rotating memory, second power means for powering the head means, third power means for inhibiting the write and read means and fourth power means for enabling said write and read head means, a memory protect circuit means operated upon application of said first power means to thereafter enable said second and third power means said memory protect circuit means further including power level monitor means operated to provide an output upon any one of said power means going out of range to first disable said fourth power means, and monitor means for sensing the speed of said rotating memory and for providing an output corresponding to said speed to enable said fourth power means so that said fourth power means enables said write and read head means in response to said monitoring means sensing certain rotating memory speeds.
Claim 2
Dependent Claim
160 words
In a rotating memory system having a rotating memory and having write and read head means, first power means for driving the rotating memory, second power means for powering the head means, third power means for inhibiting the write and read means and fourth power means for enabling said write and read head means, a memory protect circuit means operated upon application of said first power means to thereafter enable said second and third power means said memory protect circuit means further including power level monitor means operated to provide an output upon any one of said power means going out of range to first disable said fourth power means, and monitor means for sensing the speed of said rotating memory and for providing an output corresponding to said speed to enable said fourth power means so that said fourth power means enables said write and read head means in response to said monitoring means sensing certain rotating memory speeds.
Claim 3
Dependent Claim
49 words
In a rotating memory system as claimed in claim 1 wherein said rotating memory is a magnetic drum having a plurality of write and read heads associated therewith, a corresponding plurality of amplifiers and head select circuit means, wherein said third power means is for said head select means.
Claim 4
Dependent Claim
47 words
In a rotating memory system as claimed in claim 2 wherein said memory system includes at least a first and a second ''''fourth'''' power means and where said memory protect circuit means includes means connected to each said first and second ''''fourth'''' power means for receive power.
Claim 5
Dependent Claim
26 words
In a rotating memory system as claimed in claim 3 wherein said power level monitor means includes a crowbar circuit to disable said fourth power means.
Claim 6
Dependent Claim
39 words
In a rotating memory system as claimed in claim 4 wherein said memory protect circuit means includes a means to provide a reset signal to said write and read head control means prior to all power means being enabled.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |