Abstract: A method of coordinating access to a data buffer including a plurality of data blocks, using a buffer list with a plurality of entries corresponding to the data blocks. Each buffer list entry includes: (i) a status code for indicating the status of data in the corresponding data block, and (ii) a partial address common to both the next buffer list entry and a data block corresponding to said next buffer list entry. A status code is selected from a cyclical set of sequential status codes having a period of N, the status codes sequentially, and alternately, representing the most recent history of a data block, including: (i) full status, indicating data in the data block has been retrieved from the storage device or is to be stored to the storage device, or (ii) empty status, indicating data transferred out of the data block to a host or to the storage device. A store flag maintains a status code representing empty status, and a retrieve flag maintains a status code representing full status.

Abstract: A method of responding to a request for data over a bus structure, such as a SCSI bus. Upon receiving a request, a data storage device releases control of the bus and accumulates the requested data in a buffer. Before the data has been completely accumulated, the device acquires control of the bus and begins transmitting the data over the bus. The beginning of transmission occurs late enough that the transmission can occur in a single burst. If the data can be transmitted over the bus in a time period t.sub.burst, then the beginning of transmitting should begin substantially a t.sub.burst period before the time at which the buffer completes accumulating the requested data.