Data conversion method, pilot signal formation method using the same rotary magnetic head device for use therein

A method of encoding data for storage on a magnetic storage medium comprising:

• providing data arranged in data words of m bits;
• developing plural code words of n bits from each said data word of m bits, each of said plural code words for a said data word having a different known CDS (code word digital sum);
• providing a DSV (digital sum variation) control signal representative of a desired variation in DSV which can be accomplished by selection of a code word having a selected CDS;
• and
• selecting one of said plural code words having the known CDS required to produce the desired variation in DSV represented by said DSV control signal to make the DSV of said code word string correspond to desired variation in DSV.

A method of encoding data for storage on a magnetic storage medium comprising:

• providing data arranged in data words of m bits;
• developing plural code words of n bits from each said data word of m bits, each of said plural code words for a said data word having a different known CDS (code word digital sum);
• producing a digital data signal by sequentially selecting one of said plural code word associated with each of said data words, said step of producing including,
• embedding a pilot signal in the digital data signal by selecting a said plural code word associated with each of said data words which has a CDS which will produce a desired variation in DSV, thereby forming the pilot signal.

A system for encoding data for storage on a magnetic storage medium comprising:

• a converter developing plural code words of n bits from each data word of m bits, each of said plural code words associated with a said data word having a different known CDS (code word digital sum;
• means for receiving a DSV (digital sum variation) control signal representative of a desired variation in DSV which can be accomplished by selection of a code word having a selected CDS;
• and
• a DSV controller selecting one of said plural code words having the known CDS required to produce the desired variation in DSV represented by the DSV control signal to make the DSV of said code word string correspond to the desired DSV.