Title:
MAGNETIC DISK DEVICE
Document Type and Number:
Japanese Patent JPS601659
Kind Code:
A
Abstract:
PURPOSE:To increase the overall recording capacity of a magnetic disk device by performing the modulation capable of self-clock when the counted value of 0 or 1 of data is larger than a prescribed value, and the modulation incapable of self-clock when said data is smaller than a prescribed value, then recording to an allotted area. CONSTITUTION:For the signal outputted from a CPU1, a data discriminating circuit 3 decides whether the data must be applied with MFM modulation every sector and whether the self-clock is possible even with the NRZI modulation. If so, the signal is sent to an NRZI modulation/demodulation circuit 7 from a track number/sector number converting circuit 4 and a changeover switch 5. Then the signal is sent to the record/reproduction circuit 8 via a changeover switch 5' after NRZI modulation is applied and recorded to a disk 10. If the self- clock is impossible, the signal is led to an MFM modulation/demodulation circuit 6 via the circuit 4 and the siwtch 5.
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Inventors:
TAKAGI NOBUYUKI
Application Number:
JP10919483A
Publication Date:
January 07, 1985
Filing Date:
June 20, 1983
Export Citation:
Assignee:
TOSHIBA KK
International Classes:
G11B20/10; G11B5/012; G11B20/14; G11B20/16; (IPC1-7): G11B20/10
Attorney, Agent or Firm:
Noriyuki Noriyuki
Next Patent: JPS601660