code: function( lba, hpt, spt ) {
      this.cylinder = ( lba / ( spt * hpt )) | 0
      this.head     = ( lba / spt ) % hpt
      this.sector   = ( lba % spt ) + 1
      return this
    }
docs: Set CHS to a Logical Block Address (LBA)
  @param {Number} lba Logical Block Address
  @param {Number} hpt Heads per Track
  @param {Number} spt Sectors per Track
  @return {CHS}