US3806901A
Expired / Lapsed
US
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Rapid access cylindrical magnetic domain memory
Assignee: Verizon Laboratories Inc
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Filing: 1972-08-02
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Granted: 1974-04-23
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Expires: 1992-08-02
Abstract
Abstract A cylindrical magnetic domain memory is described using a plurality of main storage domain circulating loops around an auxiliary loop. A single cylindrical domain detector operatively oriented at the bits circulated in the auxiliary loop provides an output signal of those domain bits accessed from the main storage loops and after their transfer to the auxiliary loop. A reduction of access time is obtained by simultaneously transferring a selected number of predetermined bits from the main storage loops to the auxiliary loop. The bit length of the auxiliary loop and transfer tracks are selected so that after any number of circulations around the auxiliary loop, all bits can be returned in predetermined bit positions in the main storage loops.
Inventors
- 👤 C Buhrer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:09
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0875; G11C19/0883
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
254 words
A rapid access cylindrical magnetic domain memory comprising a cylindrical magnetic domain sustaining and position controlling structure including means for producing a plurality of cylindrical domain paths having sequentially spaced discrete stable cylindrical domain bit positions, and means for advancing the cylindrical domains along the tracks, said path producing means including a plurality of main storage cylindrical domain circulating loops and an auxiliary cylindrical domain circulating loop having a bit length selected to accommodate a predetermined number of bits from each of the main storage circulating loops, said path producing means further including infeed paths each for conducting cylindrical domains along discrete stable cylindrical domain positions to a main storage loop and separate outfeed paths each for conducting cylindrical domains along discrete stable cylindrical domain positions to the auxiliary loop from a main storage loop, with the number of discrete stable cylindrical domain positions in each of the infeed and outfeed paths coupled to a common main storage loop being selected to provide domain position synchronization between the main storage loops and the auxiliary loop for each full domain circulation around the auxiliary loop, switching means for coupling cylindrical domains in each of the main storage circulating loops to the auxiliary loop and for returning cylindrical domains to the main storage loops from the auxiliary loop, means for detecting cylindrical domains being circulated around the auxiliary loop, means for selectively introducing and disposing of cylindrical domains traveling along the auxiliary loop to alter information represented by the cylindrical domains in the main storage loops.
Claim 2
Dependent Claim
254 words
A rapid access cylindrical magnetic domain memory comprising a cylindrical magnetic domain sustaining and position controlling structure including means for producing a plurality of cylindrical domain paths having sequentially spaced discrete stable cylindrical domain bit positions, and means for advancing the cylindrical domains along the tracks, said path producing means including a plurality of main storage cylindrical domain circulating loops and an auxiliary cylindrical domain circulating loop having a bit length selected to accommodate a predetermined number of bits from each of the main storage circulating loops, said path producing means further including infeed paths each for conducting cylindrical domains along discrete stable cylindrical domain positions to a main storage loop and separate outfeed paths each for conducting cylindrical domains along discrete stable cylindrical domain positions to the auxiliary loop from a main storage loop, with the number of discrete stable cylindrical domain positions in each of the infeed and outfeed paths coupled to a common main storage loop being selected to provide domain position synchronization between the main storage loops and the auxiliary loop for each full domain circulation around the auxiliary loop, switching means for coupling cylindrical domains in each of the main storage circulating loops to the auxiliary loop and for returning cylindrical domains to the main storage loops from the auxiliary loop, means for detecting cylindrical domains being circulated around the auxiliary loop, means for selectively introducing and disposing of cylindrical domains traveling along the auxiliary loop to alter information represented by the cylindrical domains in the main storage loops.
Claim 3
Dependent Claim
100 words
The rapid access cylindrical magnetic domain memory as claimed in claim 1 wherein the means for advancing of the cylindrical domains further includes means for producing an in-plane rotating magnetic field which rotates at a desired frequency, means for producing a first switch current pulse during a first selected portion of the rotational cycle of the in-plane rotating magnetic field and a second current pulse during a second selected portion of the rotational cycle, both of said current pulses being selectively applied to the switching means to respectively transfer cylindrical domains between the main storage loops and the auxiliary loop.
Claim 4
Dependent Claim
44 words
The rapid access cylindrical magnetic domain memory as claimed in claim 1 wheRein the bit length of the auxiliary circulating loop is selected equal to a whole multiple of the sum of the number of predetermined bits transferred from each main storage circulating loop.
Claim 5
Dependent Claim
173 words
The rapid access cylindrical magnetic domain memory as claimed in claim 1 wherein the track producing means includes a plurality of highly permeable bars sequentially arranged to form discrete stable cylindrical domain positions, and wherein said cylindrical domains advancing means includes means for producing an in-plane rotating magnetic field with the highly permeable bars each bearing a predetermined orientation with respect to an instantaneous orientation of the in-plane rotating magnetic field, and wherein said switching means further includes conductor loops selectively located adjacent predetermined highly permeable bars at junctions between the main storage circulating loops and the auxiliary loop to cause a selected change in the travel of the cylindrical domains upon the transmission of current pulses along the conductor loop, and means for producing first and second current pulses during respectively different and selected time periods of a rotational cycle of the in-plane magnetic field and applying the first and second pulses to the switching means to control the transfer of cylindrical domain between the main storage loops and the auxiliary loop.
Claim 6
Dependent Claim
187 words
A rapid access cylindrical magnetic domain memory comprising a plurality of main storage loops and an auxiliary loop, each loop being formed of a plurality of bars of highly permeable material in close proximity to a thin magnetic cylindrical domain sustaining platelet, a magnetic domain sustaining structure including means for producing a bias magnetic field applied transverse to a surface of the platelet for stable cylindrical domains and means producing a rotating magnetic field within the plane of the thin platelet to drive the cylindrical domains from bar to bar, said auxiliary loop having separate infeed and outfeed transfer tracks with one of said infeed and one of said outfeed transfer tracks being coupled to each of the main storage cylindrical domain circulating loops, said auxiliary loop having a number of bit positions selected to accommodate a predetermined whole multiple of the number of bits transferred from each main storage loop, and further having a number of bit positions selected to provide domain position synchronization between the auxiliary loop and each main storage loop, and a cylindrical domain detector arranged to detect domains in the auxiliary loop.
Claim 7
Dependent Claim
187 words
A rapid access cylindrical magnetic domain memory comprising a plurality of main storage loops and an auxiliary loop, each loop being formed of a plurality of bars of highly permeable material in close proximity to a thin magnetic cylindrical domain sustaining platelet, a magnetic domain sustaining structure including means for producing a bias magnetic field applied transverse to a surface of the platelet for stable cylindrical domains and means producing a rotating magnetic field within the plane of the thin platelet to drive the cylindrical domains from bar to bar, said auxiliary loop having separate infeed and outfeed transfer tracks with one of said infeed and one of said outfeed transfer tracks being coupled to each of the main storage cylindrical domain circulating loops, said auxiliary loop having a number of bit positions selected to accommodate a predetermined whole multiple of the number of bits transferred from each main storage loop, and further having a number of bit positions selected to provide domain position synchronization between the auxiliary loop and each main storage loop, and a cylindrical domain detector arranged to detect domains in the auxiliary loop.
Claim 8
Dependent Claim
42 words
The rapid access cylindrical magnetic domain memory as claimed in claim 5 and further including a conductor pattern deposited on the platelet with selective proximity to predetermined bars to form domain path switches actuated by current pulses applied to the conductor pattern.
Claim 9
Dependent Claim
45 words
The rapid access cylindrical magnetic domain memory as claimed in claim 6 wherein said conductor pattern is deposited in switching proximity with bars of different orientations relative to the in-plane domain driving magnetic field to enable the same conductor to provide a plurality of switches.
Claim 10
Dependent Claim
65 words
The rapid access cylindrical magnetic domain memory as claimed in claim 7 wherein said conductor pattern includes a disposal and update conductor circuit arranged to respectively divert cylindrical domains from the auxiliary loop and introduce new cylindrical domains into the auxiliary loop, means for disposing diverted cylindrical domains, and means for generating new cylindrical domains to introduce new cylindrical domains in to the auxiliary loop.
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) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |