Patent US4126887A successfully refreshed from Google Patents.
US4126887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of controlling rotary memory
Assignee: Hitachi Ltd
•
Filing: 1976-08-17
•
Granted: 1978-11-21
•
Expires: 1996-08-17
Abstract
Abstract A method of controlling a rotary memory for preventing failure to read a recorded information block during reading of the contents of the memory. In the method, a second marker is provided separately from a first marker representing the starting point of each recorded information block so as to achieve the desired missing-free read control of the rotary memory.
Inventors
- 👤 Michio Miyazaki
- 👤 Masafumi Nozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:44
CPC Classifications
G; G11; G11B; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027; G11B20/00; G11B20/10; G11B20/12; G11B20/18; G11B20/1217; G11B2020/1257; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2508
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
144 words
A method of detecting a failure to read a recorded address marker from a rotary memory which includes a plurality of sequentially accessible recording locations each having an address area following said address marker and a data area succeeding said address area, said data area containing a given recorded data which is to be read out when said address marker is detected, said method comprising the steps of: recording an address marker ahead of said address area and a block marker between said address area and said data area in each of the recording locations; searching for said address marker in each of said recording locations; searching for said block marker when said address marker is not detected; and further searching for said undetected address marker of a given recording location when said address marker is not detected but said block marker is detected.
Claim 2
Independent Claim
144 words
A method of detecting a failure to read a recorded address marker from a rotary memory which includes a plurality of sequentially accessible recording locations each having an address area following said address marker and a data area succeeding said address area, said data area containing a given recorded data which is to be read out when said address marker is detected, said method comprising the steps of: recording an address marker ahead of said address area and a block marker between said address area and said data area in each of the recording locations; searching for said address marker in each of said recording locations; searching for said block marker when said address marker is not detected; and further searching for said undetected address marker of a given recording location when said address marker is not detected but said block marker is detected.
Claim 3
Independent Claim
165 words
A method of detecting a failure to read an address marker from a rotary memory which includes a plurality of sequentially accessible recording locations each having an address area following said address marker and a data area succeeding said address area, said data area containing a given recorded data which is to be read out when said address marker is detected, said method comprising the steps of: recording an address marker ahead of said address area in each of the recording locations whose data area is recorded with a given data and a block marker in a gap succeeding the final one of said recording locations; searching for said address marker in each of said recording locations; effecting sequential access to said recording locations for reading said given data on the basis of detection of said address marker; searching for said block marker when said address marker is not detected; and further searching for said undetected address marker upon failure to detect said block marker.
Claim 4
Independent Claim
165 words
A method of detecting a failure to read an address marker from a rotary memory which includes a plurality of sequentially accessible recording locations each having an address area following said address marker and a data area succeeding said address area, said data area containing a given recorded data which is to be read out when said address marker is detected, said method comprising the steps of: recording an address marker ahead of said address area in each of the recording locations whose data area is recorded with a given data and a block marker in a gap succeeding the final one of said recording locations; searching for said address marker in each of said recording locations; effecting sequential access to said recording locations for reading said given data on the basis of detection of said address marker; searching for said block marker when said address marker is not detected; and further searching for said undetected address marker upon failure to detect said block marker.
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) | 1981-11-20 | 1982-05-22 | 1982-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-20 | 1986-05-22 | 1986-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-20 | 1990-05-22 | 1990-11-21 | $7700.00 | Window Closed / Lapsed |