| 摘要 |
A data transfer apparatus is disclosed as typified by a floppy disk drive which, together with one or more like devices, is daisy chained to host equipment comprising a central processor unit and an associated controller. Each disk drive comprises a disk motor (20) for rotating a record disk (18) under the control of a disk motor drive circuit (46), a head motor (26) for incrementally moving a transducer head (22) radially of the record disk under the control of a head motor drive circuit (52), and a read/write circuit (64) including one or two data select gates for controlling the passage of the date read from, or to be written on, the record disk via the transducer head (22). The date select gates are under the control of a drive select signal supplied from the host equipment. The drive select signal has a first prescribed state for opening the data select gates to allow the passage of the desired data therethrough, and a second prescribed state for closing the date select gates. In order to avoid waste of electric power, at least one, preferably all, of the disk motor drive circuits (46), head motor drive circuit (52) and the read/write circuit (64) are connected to a common power line via a power control switch (100) which is closed only when the drive select signal is in the first prescribed state. |
