Memory cache device

A method of increasing the transmission rate of data from a compact disc-read only memory (CD-ROM) device to a host computer, the method comprising the steps of:

• providing a CD-ROM device for reading a compact disc, the device having an onboard random access memory (RAM) cache;
• providing a hard disk dedicated solely for storing data copied from a compact disc in the CD-ROM device;
• initially filling a clone area of the hard disk with data from the compact disc using a sequential striped fill process for copying a plurality of blocks of data from the compact disc to the hard disk, the process comprising of the steps of;
• accessing a first block of data of a sequence of data blocks from the compact disc and copying the first block onto the hard disk,
• accessing a second block of data in the sequence of data blocks from the compact disc and not copying the second block to the hard disk,
• accessing a third block of data in the sequence of data blocks from the compact disc and copying the third block onto the hard disk, the fill process continuing until the entire capacity of the hard disk devoted to cloning the compact disc is full, while leaving sufficient area for storage of blocks not initially copied during the fill process;
• initially filling a cache area of the hard disk with data from the compact disc using the sequential striped fill process for copying a plurality of blocks of data from the compact disc to the hard disk, the fill process continuing until the entire capacity of the hard disk devoted to the cache area is full, while leaving sufficient area for storage of blocks not initially copied during the fill process;
• receiving read requests of blocks of data from the host computer and fulfilling the requests using a pipelined read process, the read process comprising the steps of,
• determining requested data and the location of the data comprising the read request, if a portion of the requested data that is stored on the hard disk, then accessing the data on the hard disk and transmitting the data to the host computer, and if a portion of the requested data is stored on the compact disc, then the CD-ROM device accessing the data on the compact disc and storing the data in the onboard RAM cache thereof while the hard disk is simultaneously transmitting the data thereon to the computer,
• transmitting the data from the onboard RAM of the compact disc to the computer upon completion of the transmission of data from the hard disk to the computer, the read process being repeated until all requested blocks of data have been retrieved and transmitted to the computer;
• and
• filling in not copied blocks of data in the clone area and cache area of the hard disk not copied from the compact disc during the striped fill process, the blocks of data being filled in during interludes between read requests from the computer.