Abstract: A magnetic tape system includes a driving unit (1) including a magnetic head (14), reels (11, 12) for winding a magnetic tape (16) thereon and a drive portion for driving the reels; a drive control unit (2, 20, 21) for controlling the drive unit; and a prefetch control unit (3) having a first memory for prefetching a plurality of commands from the host controller and a second memory for temporarily storing data from the host controller or data read out from the magnetic tape. The drive unit is operated through the drive control unit according to the commands stored in the first memory and the results of the operation are reported to the host controller.

Abstract: A magnetic tape system for efficient and proper prefetching at the end of the tape. The system includes a drive mechanism (1), a drive control unit (2, 20, 21) for controlling the drive mechanism based on commands to write data on the read data from the magnetic tape and a prefetch control unit. The prefetch control unit stores a plurality of write commands from a host system, including write commands which are not accompanied with write data from the host system, and a plurality of read and write data. The drive control unit operates the drive mechanism based on the write commands stored in the first memory. The prefetch control unit reduces the number of prefetched write commands stored therein after receipt of an early warning for the end of tape (EWA) signal. Preferably, the prefetchings of write commands are reduced when a write command sent from the host system is received.