US5414850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for transparently compressing data files in a computer system
Assignee: HI/FN Inc
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Filing: 1991-08-23
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Granted: 1995-05-09
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Expires: 2011-08-23
Abstract
Abstract A data compression device driver compresses and decompresses files on a disk drive in a computer system when a user copies files from a drive letter assigned to the disk drive to a drive letter assigned to the data compression device driver. Drive parameter blocks for the disk drive and for the data compression device driver contain the assigned drive letter, disk geometry information, a rebuild flag, and a pointer to the device driver. A swapping means swaps the device driver pointers in the drive parameter blocks corresponding to the disk drive and the data compression device driver. From then on, compressed data files may be accessed transparently by using the drive letter which was originally assigned to the disk drive before swapping, which now refers to the data compression device driver.
Inventors
- 👤 Douglas L. Whiting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:33
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/00007; G06; G06F; G06F16/00; G06F16/10; G06F16/17; G06F16/174; G06F16/1744
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A method for maintaining compressed data files on a disk drive in a computer system so that a user may access said data files as if they were uncompressed, said disk drive having a drive letter assigned by an operating system, said operating system storing with said assigned drive letter a device driver pointer to said disk drive, said method comprising: compressing and decompressing one or more files on said disk drive with a device driver, said compressing and decompressing device driver having a drive letter assigned by said operating system, said operating system storing with said assigned drive letter for said compressing and decompressing device driver a device driver pointer to said compressing and decompressing device driver; and swapping said device driver pointer stored with said drive letter assigned to said disk drive and said device driver pointer stored with said drive letter assigned to said compressing and decompressing device driver.
Claim 2
Independent Claim
152 words
A method for maintaining compressed data files on a disk drive in a computer system so that a user may access said data files as if they were uncompressed, said disk drive having a drive letter assigned by an operating system, said operating system storing with said assigned drive letter a device driver pointer to said disk drive, said method comprising: compressing and decompressing one or more files on said disk drive with a device driver, said compressing and decompressing device driver having a drive letter assigned by said operating system, said operating system storing with said assigned drive letter for said compressing and decompressing device driver a device driver pointer to said compressing and decompressing device driver; and swapping said device driver pointer stored with said drive letter assigned to said disk drive and said device driver pointer stored with said drive letter assigned to said compressing and decompressing device driver.
Claim 3
Dependent Claim
67 words
The method of claim 1 wherein said disk drive comprises a first portion referenced directly by said drive letter assigned to said disk drive and a second portion referenced through said compressing and decompressing device driver by said drive letter assigned to said compressing and decompressing device driver, said first portion for storing said data files uncompressed and said second portion for storing said data files compressed.
Claim 4
Dependent Claim
58 words
The method of claim 2 wherein said operating system maintains a table containing a drive parameter block for storing information regarding each of said first and said second portions of said disk drive, each of said drive parameter blocks containing said information including said assigned drive letter, said device driver pointer, disk geometry information, and a rebuild flag.
Claim 5
Dependent Claim
40 words
The method of claim 3 further comprising compressing data files before storing said data files on said second portion of said disk drive, and decompressing data files before accessing said data files from said second portion of said disk drive.
Claim 6
Dependent Claim
33 words
The method of claim 3 wherein said swapping step further comprises swapping information in addition to said device driver pointer in said drive parameter blocks corresponding to said first and second disk portions.
Claim 7
Dependent Claim
28 words
The method of claim 3 wherein said swapping step further comprises setting said rebuild flags in said drive parameter blocks corresponding to said first and second disk portions.
Claim 8
Independent Claim
96 words
A method for maintaining compressed data files on a disk drive in a computer system so that a user may access said data files as if they were uncompressed, said disk drive having a drive letter assigned by an operating system, said method comprising: compressing and decompressing one or more files on said disk drive with a device driver, said compressing and decompressing device driver having a drive letter assigned by said operating system; and swapping said drive letter assigned to said disk drive and said drive letter assigned to said compressing and decompressing device driver.
Claim 9
Independent Claim
96 words
A method for maintaining compressed data files on a disk drive in a computer system so that a user may access said data files as if they were uncompressed, said disk drive having a drive letter assigned by an operating system, said method comprising: compressing and decompressing one or more files on said disk drive with a device driver, said compressing and decompressing device driver having a drive letter assigned by said operating system; and swapping said drive letter assigned to said disk drive and said drive letter assigned to said compressing and decompressing device driver.
References Cited (Backward Citations)
US4982324A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-05-08 | 1998-11-07 | 1999-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-08 | 2002-11-07 | 2003-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-08 | 2006-11-07 | 2007-05-09 | $7700.00 | Window Closed / Lapsed |