Abstract: A method and apparatus for reverting a disk drive to an earlier point in time is disclosed. Changes made to the drive are saved in a circular history buffer which includes the old data, the time it was replaced by new data, and the original location of the data. The circular history buffer may also be implemented by saving new data elements into new locations and leaving the old data elements in their original locations. References to the new data elements are mapped to the new location. The disk drive is reverted to an earlier point in time by replacing the new data elements with the original data elements retrieved from the history buffer, or in the case of the other embodiment, reads to the disk are mapped to the old data elements stilled stored in their original locations. The method and apparatus may be implemented as part of an operating system, or as a separate program, or in the controller for the disk drive. The method and apparatus are applicable to other forms of data storage as well.

Abstract: A method and apparatus for reverting a disk drive to an earlier point in time is disclosed. Changes made to the drive are saved in a circular history buffer which includes the old data, the time it was replaced by new data, and the original location of the data. The circular history buffer may also be implemented by saving new data elements into new locations and leaving the old data elements in their original locations. References to the new data elements are mapped to the new location. The disk drive is reverted to an earlier point in time by replacing the new data elements with the original data elements retrieved from the history buffer, or in the case of the other embodiment, reads to the disk are mapped to the old data elements stilled stored in their original locations. The method and apparatus may be implemented as part of an operating system, or as a separate program, or in the controller for the disk drive. The method and apparatus are applicable to other forms of data storage as well.

Abstract: A filing system is provided for locating a particular file contained in a file holder which contains a plurality of files. The apparatus includes a machine-readable code mounted on each of the files, a guide attached to each file holder, a scanner for reading the codes on the files in a file holder, and an indicator for indicating when the particular machine-readable code corresponding to the particular file is located. The apparatus uses an improved bar code in which character boundaries are eliminated and the number of ONE's and ZERO's in a code are variable, resulting in increased data density. The unique numeric values which result from the improved bar code sparsely populate the possible range of values, and therefore a mapping algorithm is provided to map the bar code values to a sequential numeric system for ease of use.

Abstract: A filing system is provided for locating a particular file contained in a file holder which contains a plurality of files. The apparatus includes a machine-readable code mounted on each of the files, a guide attached to each file holder, a scanner for reading the codes on the files in a file holder, and an indicator for indicating when the particular machine-readable code corresponding to the particular file is located. The apparatus uses an improved bar code in which character boundaries are eliminated and the numbers of ONE's and ZERO's in a code are variable, resulting in increased data density. The unique numeric values which result from the improved bar code sparsely populate the possible range of values, and therefore a mapping algorithm is provided to map the bar code values to a sequential numeric system for case of use.

Abstract: A filing system is provided for locating a particular file contained in a file holder which contains a plurality of files. The apparatus includes a machine-readable code mounted on each of the files, a guide attached to each file holder, a scanner for reading the codes on the files in a file holder, and an indicator for indicating when the particular machine-readable code corresponding to the particular file is located. The apparatus uses an improved bar code in which character boundaries are eliminated and the number of ONE's and ZERO's in a code are variable, resulting in increased data density. The unique numeric values which result from the improved bar code sparsely populate the possible range of values, and therefore a mapping algorithm is provided to map the bar code values to a sequential numeric system for ease of use.