System for retrieval of a data record by buffering the record in segments and beginning transmission prior to the buffer obtaining the entire record

A method for reading data from a rotating media in a data storage device,

• said rotating media having a plurality of tracks, a plurality of records subdividing said plurality of tracks, and a plurality of sectors subdividing said plurality of records;
• said data storage device having a plurality of read/write heads for reading and writing said rotating media, a control module in communication contact with and interposed between a control unit and said plurality of read/write heads, said control unit in communication contact with a processor by a data channel:
• plurality of buffer memory means wherein each one of said plurality of read/write heads is coupled to a separate one of said plurality of buffer memory means;
• said method comprising:
• detecting, in response to a data read request received from said processor identifying a requested data record, a first sector boundary encompassed by said requested data record as said first sector boundary appears under a specific one of said plurality of read/write heads which is closest to the first sector boundary subsequent to said data read request;
• identifying a beginning of said requested data record;
• reading a first segment of said requested data, from said a specific one first sector boundary to the end of said requested data record, into a specific one of said plurality of buffer memories which corresponds to said specific one of said plurality of read/write heads;
• transmitting said first segment of said requested data stored in said specific buffer memory means to said control module;
• transferring said first segment of said requested data record to said processor prior to said specific one of said plurality of read/writ heads completing said data read request for said requested data record;
• reading a second segment of having a plurality of portions of said requested data record, from said identified beginning of said requested data record to said first sector boundary, into said specific buffer memory means;
• transmitting a first portion of said second segment stored in said specific buffer memory means to said control module;
• and
• transferring the first portion of said second segment of said requested data record stored in said control module to said processor prior to said specific one of said plurality of read/write heads reaching said first sector boundary while reading other portions of said second segment, upon reaching said first sector boundary completing transferring of said second segment, thereby completing transmission of said requested data record to said processor.

A data storage system connected to a processor for storing data, comprising:

• a control module;
• a plurality of rotating media;
• a plurality of read/write heads for writing data onto one of said plurality of rotating media;
• means, responsive to a data read request, for detecting a first sector boundary encompassed by a requested data record on a track and appearing under a specific one of said plurality of read/write heads which is closest to the first sector boundary subsequent to said data read request;
• means for reading a first segment of said requested data record, from said first sector boundary to an end of said data record, into a specific one of a boundary buffer memory means interposed between one of said plurality of read/write heads and a bus wherein each one of said plurality of read/write heads is coupled to a separate one of said plurality of buffer memory means and the specific buffer memory corresponds to said specific one of said plurality of read/write heads;
• means for transmitting said first segment of said requested data record stored in said specific buffer memory means to said control module by way of said bus;
• means, responsive to said detecting means, for activating said transmitting means prior to said specific one of said plurality of read/write heads reaching said end of said requested data record, including:
• means for calculating a first length of time required for said transmitting means to transmit said first segment of said requested data record to said control module by way of said bus;
• means for enabling said transmitting means and said means for calculating in advance of said specific one of said plurality of read/write heads reaching said end of said requested data record;
• means, in said control module, for transferring said first segment of said requested data record to said processor prior to said specific one of said read/write heads completing the said data read request of said requested data record;
• means for identifying a beginning of said requested data record on said track;
• wherein said reading means is responsive to said identifying means for reading a second segment having a plurality of portions of said requested data from said beginning of said requested data record to said first sector boundary, into said specific buffer memory means;
• wherein said calculating means is responsive to said identifying means for calculating a second length of time required for said transmitting means to transmit said second segment of said requested data record to said control module by way of said bus;
• and
• wherein said enabling means is further responsive to said calculating means for enabling said transmitting means said second segment transmission time in advance of said first sector boundary
• means for transmitting a first portion of said second segment stored in said specific buffer memory means to said control module;
• and
• wherein said transferring means transfers to first portion of a said second segment of said requested data record stored in said control module to said processor prior to said specific one of said plurality of read/write heads reaching said first sector boundary while reading other portions of said second segment, upon reaching said first sector boundary completing transferring of said second segment, thereby completing transmission of said requested data record to said processor.