Abstract: Rather than comparing an old file with a new file to generate a set of patching instructions, and then compressing the patching instructions to generate a compact patch file for transmission to a user, a patch file is generated in a single operation. A compressor is pre-initialized in accordance with the old version of the file (e.g. in an LZ77 compressor, the history window is pre-loaded with the file). The pre-initialized compressor then compresses the old file, producing a patch file from which the new file can be generated. At the user's computer, a parallel process is performed, with the user's copy of the old file being used to pre-initialize a decompressor to which the patch file is then input. The output of the decompressor is the new file. The patch files generated and used in these processes are of significantly reduced size when compared to the prior art.

Abstract: A method and apparatus for maximizing the data storage capacity of a floppy diskette. The present invention provides a format that reduces the inter-sector gap between adjacent sectors on each track to eight bytes. The storage space gained from the reduction in gap size is used to add additional sectors to each track on the diskette, thereby providing a total of twenty-one sectors per track. Because the gap between sectors is reduced to such a small size, the disk controller may not be able to process the data from one sector before the adjacent sector is to be read. Therefore, sectors are arranged on each track in a 2:1 interleave arrangement, such that one sector separates consecutively-numbered sectors. Additionally, to increase performance, the end of the last sector on each track is offset from the beginning of the first sector on the next track by four sectors.