Browse Prior Art Database

Increasing Capacity of Storage Device

IP.com Disclosure Number: IPCOM000091485D
Original Publication Date: 1968-Feb-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Abbott, GF: AUTHOR

Abstract

This technique is for increasing the capacity of magnetic storage mediums for digital data by utilizing communications techniques. The technique utilizes the bandwidth-noise-error relationships to place more information into the storage medium. The circuit accommodates the recording of four bits at a time in sixteen analog levels with very low error rates on conventional magnetic recording media having a signal-to-noise of approximately 40 db or better.

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Increasing Capacity of Storage Device

This technique is for increasing the capacity of magnetic storage mediums for digital data by utilizing communications techniques. The technique utilizes the bandwidth-noise-error relationships to place more information into the storage medium. The circuit accommodates the recording of four bits at a time in sixteen analog levels with very low error rates on conventional magnetic recording media having a signal-to-noise of approximately 40 db or better.

The data from the digital source is deserialized, converted to a corresponding analog voltage and applied to the control input of a variable frequency oscillator. There is secured a frequency-modulated carrier having an instantaneous frequency corresponding to the value of groups of successive data bits, in this example four. The frequency modulated carrier signal provided by the oscillator is recorded on the magnetic media.

Readout of the data is substantially a reversal of the above process. The frequency-modulated carrier signal on the magnetic media is applied to a discriminator. The latter provides a DC voltage corresponding to the instantaneous frequency. This voltage is converted to parallel data bits, in this example four, which are identical to those initially supplied by the deserializer and then serialized to restore the data to the same format supplied by the digital data source.

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