Method and apparatus for distinguishing between diskettes in a d

Details Method and apparatus for distinguishing between diskettes in a d Method and apparatus for distinguishing between diskettes in a d

1986-03-31

1987-11-24

Atkinson, Charles E.

Excavating

360 53, 360 60, G06F 1110, G11B 502

Patent

active

047093676

ABSTRACT:
A method and apparatus are disclosed for enabling a diskette drive system to distinguish between diskettes and verify that the diskette currently in the drive is the correct one. Each diskette contains a file allocation table for controlling the allocation and deallocation of storage space on the diskette. Each time that the file allocation table on a diskette is accessed, i.e., read or written, a cyclic redundancy check (CRC) value for the file allocation table is calculated and stored. When checking the validity of a diskette, i.e., that the correct diskette is in the drive, a CRC value for the file allocation table of the currently loaded diskette is calculated and compared to the most recently stored CRC value. If the most recently calculated CRC value does not match the most recently stored CRC value, then this is an indication that the wrong diskette is currently in the diskette drive. A warning is then provided to the system user to change diskettes before a read or a write operation will be commenced.

REFERENCES:
patent: 4380029 (1983-04-01), Bode
patent: 4562577 (1985-12-01), Glover et al.
patent: 4577289 (1986-03-01), Comerford et al.
patent: 4578722 (1986-03-01), Lovgren et al.
patent: 4622598 (1986-11-01), Doi et al.
patent: 4637023 (1987-01-01), Lounsbury et al.
patent: 4644545 (1987-02-01), Gershenson
IBM Technical Disclosure Bulletin, vol. 28, No. 2, Jul., 1985, "Diagnostic Technique for Use in Disk Drive Controllers", pp. 739-740.
Waddell, IBM Technical Disclosure Bulletin, vol. 27, No. 6, Nov., 1984, pp. 3580-3581, "Forcing CRC Errors on Diskettes".

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