Methods and apparatus are disclosed for buffering and reordering data blocks read simultaneously from multiple tracks of an optical disk, so that they may be delivered in sequential order to a host computer. The methods involve the use of numerous processes to receive read commands, position an optical pickup, handle memory management tasks, process data blocks as they arrive, and send data blocks to the host computer in sequential order as they become available. The reordering of data blocks is achieved by checking each data block as it arrives in a "read process" to see if it may be linked in a sequential chain with a data block that arrived from the next track. Additionally, methods for determining if a requested data block is in the range of blocks that are currently being read, and methods for determining when the optical pickup may be moved to read the next set of tracks are described.