Tape drive emulation system for a disk drive
AssigneeMiltope Corporation
InventorsBarry Plotkin, Daniel C. Ginsburg
Life of this patent
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Abstract
The invention relates to an emulator system which allows a disk drive to transparently emulate a tape drive. The system converts sequential format tape records into block format disk records and visa-versa. Identification and conversion information for each of the data records are stored in directory located on the outermost sectors of the disk. Within each directory are a plurality of entries each containing four fields: TAPE RECORD NUMBER (TRN); DISK START ADDRESS (DSA); WORD COUNT (WC); and FLAG. These fields contain all of the necessary information required to map a tape formatted data record to a disk and thereafter retrieve the data record from the disk and convert it back to tape format.
Claims12
A tape drive emulation system, for allowing a disk drive device, connected to a host computer through a tape drive interface, to transparently emulate a tape drive device, comprising:
- first recording means for recording a master directory containing a plurality of sequentially numbered entries to an area on a disk, each of said sequentially numbered entries corresponding to a sequentially numbered tape data record, each of said entries containing a DISK START ADDRESS field;
- converting means for converting said tape data record to a disk format data record;
- and
- second recording means for recording said disk format data record to said disk starting at an address specified by said DISK START ADDRESS field of said corresponding entry.
A method for mapping tape format data records to a disk, comprising the steps of:
- recording a master directory to said disk, said master directory comprised of a plurality of sequentially numbered entries, each of said entries corresponding a sequentially numbered tape data record;
- storing a disk start address for each of said tape data records in said corresponding entry;
- converting said tape data records to disk format data records;
- writing said disk format data records to said disk at said disk start address stored in said corresponding entry;
- and
- setting a flag within said corresponding entry to indicate a valid data record.
Dependencies are inferred from the claim text.