ASSEMBLY INCLUDING A FLEXIBLE DISK AND A DISKDRIVE THEREFOR

摘要

Control information for a flexible magnetic disk storage assembly is recorded on the periphery of the disk in a region not used for recording data. The control information is read through the protective cover or envelope which encloses the disk by means of a magnetic transducer such as a four track audio cassette head which bears against the envelope. By recording index and sector pulses as part of the control information, hard sectoring can be inexpensively and accurately achieved. A recorded fixed frequency control signal can be read and used as part of the feedback loop in a phase locked oscillator used to control a d.c. motor driving the spindle. The control information can also include servo tracks which assist in registering the data transducer directly over data tracks on media which has changed its dimensions.