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US3670307A Expired / Lapsed US ⏱️ 0.0 years remaining

Interstorage transfer mechanism

Assignee: International Business Machines Corp
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Filing: 1969-12-23
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Granted: 1972-06-13
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Expires: 1989-12-23
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Abstract

Abstract Described is an interstorage transfer mechanism suitable for use in a storage control system for a two-level storage, wherein the storage system includes a high-speed storage against which requests for data are processed and a slower, larger-capacity main storage. Requests can be received and serviced concurrently at a plurality of request ports in the system where they are buffered in the request stacks. A tag storage serves as an index to the data concurrently resident in high-speed storage and a directory storage acts as an index to data currently in main storage. Requests for data in each port cause the tag storage to be interrogated to determine whether the desired data is in highspeed storage. If not, then the desired data is retrieved from main storage and placed into high-speed storage by the interstorage transfer mechanism. Priority means for accessing said high-speed storage are provided, said interstorage transfer mechanism being given first priority to access said high-speed and tag storages in case of conflicts in access between said interstorage transfer mechanism and at least one of said plurality of request ports. Means are provided for choosing a target address in High-speed storage wherein said desired data will be relocated. The tag indexing said target address is updated by said interstorage transfer mechanism to reflect the new data. Means are further provided for invalidating all requests currently in transit at the time said tag is changed to insure data integrity in case said requests refer to old data in said target line. The aforementioned tags contain a bit indicating that the corresponding address in high-speed storage has recently been accessed. Cold generator means are provided for periodically resetting this bit in each tag to mark the corresponding high-speed storage physical address as a candidate for replacement target.

Inventors

  • 👤 Richard F Arnold
  • 👤 Philip S Dauber
  • 👤 Charles V Freiman
  • 👤 Russel J Robelen
  • 👤 John R Wlerzbicki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 15:56
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/02; G06F12/08; G06F12/0802; G06F12/0804

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 285 words
In a system wherein requests to access data in a storage system are received from a plurality of requestors at individual request ports, and said storage system comprises a main storage containing a large amount of data, a high-speed storage containing a lesser amount of data against which said requests are processed, a high-speed-storage index for indexing the data currently resident in said high-speed-storage, and control means for concurrently servicing said requests for accessing data from said high-speed-storage means, the combination of an interstorage transfer mechanism for transferring data between said high-speed storage and said main storage comprising: a. control apparatus including first storage means for storing the address of a target location in said high-speed storage into which new data is to be transferred to replace old data resident in such location and second storage means for storing control information to control said transfer; b. indicating means in said high-speed storage index for indicating the status of old data therein as to whether the contents of said target location are changed or unchanged relative to the data initially stored therein; c. means for accessing said indicating means in said high-speedstorage index and providing a signal indicative of said status; d. means responsive to said signal indicating a changed status for transferring said old data from said target location into said main storage; e. means responsive to said signal indicating an unchanged status or to the completion of the transfer of said old data, for accessing said main storage and retrieving therefrom, under control of said control information, said new data to be transferred; and means for accessing said high-speed storage for transferring into said target location said new data retrieved from said main storage.
Claim 2
Dependent Claim 285 words
In a system wherein requests to access data in a storage system are received from a plurality of requestors at individual request ports, and said storage system comprises a main storage containing a large amount of data, a high-speed storage containing a lesser amount of data against which said requests are processed, a high-speed-storage index for indexing the data currently resident in said high-speed-storage, and control means for concurrently servicing said requests for accessing data from said high-speed-storage means, the combination of an interstorage transfer mechanism for transferring data between said high-speed storage and said main storage comprising: a. control apparatus including first storage means for storing the address of a target location in said high-speed storage into which new data is to be transferred to replace old data resident in such location and second storage means for storing control information to control said transfer; b. indicating means in said high-speed storage index for indicating the status of old data therein as to whether the contents of said target location are changed or unchanged relative to the data initially stored therein; c. means for accessing said indicating means in said high-speedstorage index and providing a signal indicative of said status; d. means responsive to said signal indicating a changed status for transferring said old data from said target location into said main storage; e. means responsive to said signal indicating an unchanged status or to the completion of the transfer of said old data, for accessing said main storage and retrieving therefrom, under control of said control information, said new data to be transferred; and means for accessing said high-speed storage for transferring into said target location said new data retrieved from said main storage.
Claim 3
Dependent Claim 32 words
The combination of claim 1 including means for appending to said high-speed-storage index to said target location an indication that data is in transit between said main storage and said target location.
Claim 4
Dependent Claim 24 words
The combination of claim 2 wherein said request for access to data identifies the location of such data in terms of a logical address.
Claim 5
Dependent Claim 27 words
The combination of claim 3 further including means connected to receive requests from said ports for randomizing each said logical address into a plurality of physical addresses.
Claim 6
Dependent Claim 27 words
The combination of claim 4 comprising: a plurality of main storage output buffers connected to said main storage for receiving said retrieved data from said main storage.
Claim 7
Dependent Claim 31 words
The combination of claim 5 comprising: a plurality of input buffers, greater in number than said plurality of main storage output buffers, said input buffers being connected to said high-speed storage.
Claim 8
Dependent Claim 28 words
The combination of claim 6 wherein data words are retrieved from main storage in groups containing less data entities than are containable in said plurality of input buffers.
Claim 9
Dependent Claim 30 words
The combination of claim 7 further including selectively actuated means for gating said data entities from said main storage output buffers to said high-speed storage input buffers in different formats.
Claim 10
Dependent Claim 27 words
The combination of claim 1 wherein said interstorage transfer mechanism includes means for operating said mechanism concurrently while other requests are being serviced in said storage system.
Claim 11
Dependent Claim 31 words
The combination of claim 1 wherein said interstorage transfer mechanism includes means for invalidating requests in progress through said storage system substantially concurrently with said accessing of said high-speed storage indices.

References Cited (Backward Citations)

US3217298A Cited
US3218611A Cited
US3394353A Cited
US3292152A Cited
US3292153A Cited
US3341817A Cited
US3422401A Cited
US3478321A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-06-13 1975-12-13 1976-06-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-06-13 1979-12-13 1980-06-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-06-13 1983-12-13 1984-06-13 $7700.00 Window Closed / Lapsed

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