Method and apparatus using multiple codes to increase storage capacity

Claim 1

A method for increasing the effective storage capacity of a disk storage device, comprising the steps of: (a) partitioning recording tracks of the device into a plurality of concentric recording bands, including a first band surrounded by an outer second band; (b) providing a first encoder for encoding data in one run-length-limited code for recording on said first band: (c) providing another encoder for encoding data for recording on said second band in another run-length-limited code having a higher code rate; (d) providing a write driver operative at one clock frequency; and (e) responsive to the track address designated in a disk write command, selectively connecting one of said encoders to the write driver for recording data at said one frequency on that band which includes said address; (f) using a detector operative at said one clock frequency and one decoder, decoding data recorded in said first band; (g) using said detector operative at said one clock frequency and another decoder, decoding data recorded in said second band; and (h) responsive to the track address in a disk read command, selectively connecting one of the decoders to the detector for reading data at said one frequency on that band which includes the last mentioned address.

Claim 2

A method for increasing the effective storage capacity of a disk storage device, comprising the steps of: (a) partitioning recording tracks of the device into a plurality of concentric recording bands, including a first band surrounded by an outer second band; (b) providing a first encoder for encoding data in one run-length-limited code for recording on said first band: (c) providing another encoder for encoding data for recording on said second band in another run-length-limited code having a higher code rate; (d) providing a write driver operative at one clock frequency; and (e) responsive to the track address designated in a disk write command, selectively connecting one of said encoders to the write driver for recording data at said one frequency on that band which includes said address; (f) using a detector operative at said one clock frequency and one decoder, decoding data recorded in said first band; (g) using said detector operative at said one clock frequency and another decoder, decoding data recorded in said second band; and (h) responsive to the track address in a disk read command, selectively connecting one of the decoders to the detector for reading data at said one frequency on that band which includes the last mentioned address.

Claim 6

A method for increasing the effective storage capacity of a disk storage device, comprising the steps of: (a) partitioning recording tracks of the device into a plurality of concentric recording bands, including a first band surrounded by an outer second band; (b) using a detector operative at one clock frequency and one decoder, decoding data recorded on said first band in a first run-length-limited code; (c) using the same detector operative at said one frequency and another decoder, decoding data recorded on said second band in a second run-length-limited code having a higher code rate than said first run-length-limited code; and (d) responsive to the track address designated in a disk read command, selectively connecting one of said decoders to the detector for reading data at said frequency on that band which includes said address.

Claim 7

A method for increasing the effective storage capacity of a disk storage device, comprising the steps of: (a) partitioning recording tracks of the device into a plurality of concentric recording bands, including a first band surrounded by an outer second band; (b) using a detector operative at one clock frequency and one decoder, decoding data recorded on said first band in a first run-length-limited code; (c) using the same detector operative at said one frequency and another decoder, decoding data recorded on said second band in a second run-length-limited code having a higher code rate than said first run-length-limited code; and (d) responsive to the track address designated in a disk read command, selectively connecting one of said decoders to the detector for reading data at said frequency on that band which includes said address.

Claim 8

A method for increasing the effective storage capacity of a disk storage device, comprising the steps of: (a) partitioning recording tracks of the device into a plurality of concentric recording bands, including a first band surrounded by an outer second band; (b) providing a first encoder for encoding data in one run-length-limited code for recording on said first band: (c) providing another encoder for encoding data for recording on said second band in another run-length-limited code having a higher code rate; (d) providing a write driver operative at a selected frequency; and (e) responsive to the track address designated in a disk write command, selectively connecting one of said encoders to the write driver for recording data at said frequency on that band which includes said address.

Claim 9

A method for increasing the effective storage capacity of a disk storage device, comprising the steps of: (a) partitioning recording tracks of the device into a plurality of concentric recording bands, including a first band surrounded by an outer second band; (b) providing a first encoder for encoding data in one run-length-limited code for recording on said first band: (c) providing another encoder for encoding data for recording on said second band in another run-length-limited code having a higher code rate; (d) providing a write driver operative at a selected frequency; and (e) responsive to the track address designated in a disk write command, selectively connecting one of said encoders to the write driver for recording data at said frequency on that band which includes said address.