| 摘要 |
PURPOSE:To minimize a wasteful use of a disc space to shorten the latency time, by reading or writing data from or into a sector nearest to the current head position when a readout or write instruction does not designate a sector address. CONSTITUTION:Control data 5 is sent from a CPU1 to a disc control device 3 through a channel device 2 to control a magnetic disc 4. This control data 4 consists of a cylinder address 51, a track address 52, and a sector address 53, and an instruction which discriminates whether a new sector address is designated or not is applied to the address 53. The control device 3 discriminates whether the instruction is a write or readout instruction and discriminates whether the address designation is necessary or not; and if the address designation is unnecessary, data is readout or written from or into a sector nearest to the current head position after the head is positioned to the objective track, and thus, a wasteful use of a disc space is minimized to shorten the latency time. |
