Emulating records in one record format in another record format

Claim 1

A method of writing, on a recording disk formatted in fixed-block architecture (FBA) in fixed-length blocks, count-key-data (CKD)-formatted binary data records that are separated by interrecord gaps, comprising the steps of: writing the CKD-formatted records into a buffer; using an emulator, reorienting the records written into the buffer to create CKD-emulated records in FBA format by eliminating, from each CKD-formatted record before it is written to the disk, intrarecord gaps and bytes not essential for recreating the data in the respective CKD-emulated records in CKD format; using the emulator, calculating the number and location of fixed-length blocks required to store each CKD-emulated record in a virtual track on the disk, where each virtual track consists of a predetermined number of fixed-length blocks at predetermined consecutive locations; and using the emulator, writing to the disk the CKD-emulated records from the buffer via an FBA adaptor in fixed-length blocks containing (i) header data indicating whether or not a CKD-emulated record begins in each such block, (ii) a number indicating byte displacement address, and (iii) padding bytes between each set of adjacent CKD-emulated records including bytes corresponding to the interrecord gaps to assure that the beginning of each respective CKD-emulated record has the same byte displacement from a reference location on a virtual track on the disk as each respective corresponding CKD-formatted record would have from an index on a physical track of a CKD-formatted disk so that each CKD-emulated record can be accessed in a single revolution of the FBA-formatted disk by use of its byte displacement from its reference location as an address, without requiring a special directory or map list.

Claim 2

A method of writing, on a recording disk formatted in fixed-block architecture (FBA) in fixed-length blocks, count-key-data (CKD)-formatted binary data records that are separated by interrecord gaps, comprising the steps of: writing the CKD-formatted records into a buffer; using an emulator, reorienting the records written into the buffer to create CKD-emulated records in FBA format by eliminating, from each CKD-formatted record before it is written to the disk, intrarecord gaps and bytes not essential for recreating the data in the respective CKD-emulated records in CKD format; using the emulator, calculating the number and location of fixed-length blocks required to store each CKD-emulated record in a virtual track on the disk, where each virtual track consists of a predetermined number of fixed-length blocks at predetermined consecutive locations; and using the emulator, writing to the disk the CKD-emulated records from the buffer via an FBA adaptor in fixed-length blocks containing (i) header data indicating whether or not a CKD-emulated record begins in each such block, (ii) a number indicating byte displacement address, and (iii) padding bytes between each set of adjacent CKD-emulated records including bytes corresponding to the interrecord gaps to assure that the beginning of each respective CKD-emulated record has the same byte displacement from a reference location on a virtual track on the disk as each respective corresponding CKD-formatted record would have from an index on a physical track of a CKD-formatted disk so that each CKD-emulated record can be accessed in a single revolution of the FBA-formatted disk by use of its byte displacement from its reference location as an address, without requiring a special directory or map list.

Claim 7

An apparatus for recording count key data (CKD)-formatted binary data records, comprising: a recording disk formatted in fixed-block architecture (FBA) with fixed-length data blocks; a buffer; en emulator connected to the buffer for generating, from each CKD-formatted record and storing in the buffer, a CKD-emulated record in FBA format; an FBA adaptor operatively connected to the emulator and the disk for transmitting CKD-emulated records from the buffer under the control of the emulator to the disk for recording thereon in virtual tracks, where each virtual track consists of a predetermined number of fixed-length blocks at predetermined consecutive locations; and said emulator being operative to (i) remove from each CKD-emulated record bytes not essential for recreating in CKD format the data of that respective CKD-formatted record, (ii) calculate the number and location of fixed-length blocks required to store each CKD-emulated record in a virtual track on the disk, (iii) provide, in each block, a number relating to byte displacement address and a binary indicator indicating whether a CKD-emulated record begins in such block, and (iv) provide, between adjacent CKD-emulated records, padding bytes in number sufficient to assure that the beginning of each respective CKD-emulated record has the same byte displacement from a single reference location in a virtual track on the FBA-formatted disk as each respective corresponding CKD-formatted record would have from an index if recorded on a physical track of a CKD-formatted disk.

Claim 8

An apparatus for recording count key data (CKD)-formatted binary data records, comprising: a recording disk formatted in fixed-block architecture (FBA) with fixed-length data blocks; a buffer; en emulator connected to the buffer for generating, from each CKD-formatted record and storing in the buffer, a CKD-emulated record in FBA format; an FBA adaptor operatively connected to the emulator and the disk for transmitting CKD-emulated records from the buffer under the control of the emulator to the disk for recording thereon in virtual tracks, where each virtual track consists of a predetermined number of fixed-length blocks at predetermined consecutive locations; and said emulator being operative to (i) remove from each CKD-emulated record bytes not essential for recreating in CKD format the data of that respective CKD-formatted record, (ii) calculate the number and location of fixed-length blocks required to store each CKD-emulated record in a virtual track on the disk, (iii) provide, in each block, a number relating to byte displacement address and a binary indicator indicating whether a CKD-emulated record begins in such block, and (iv) provide, between adjacent CKD-emulated records, padding bytes in number sufficient to assure that the beginning of each respective CKD-emulated record has the same byte displacement from a single reference location in a virtual track on the FBA-formatted disk as each respective corresponding CKD-formatted record would have from an index if recorded on a physical track of a CKD-formatted disk.