Browse Prior Art Database

Multiple Disk Writing for Hard-Disk Drive

IP.com Disclosure Number: IPCOM000106133D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Nakamura, T: AUTHOR [+3]

Abstract

Disclosed is a method for writing same data (servo data) on multiple disks of a hard disk drive at a time.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 95% of the total text.

Multiple Disk Writing for Hard-Disk Drive

      Disclosed is a method for writing same data (servo data) on
multiple disks of a hard disk drive at a time.

     On servo writing for the embedded servo, same data should be
written on all disk surfaces.  However, since only one head could be
selected at a time, it took one revolution to complete servo writing
on one surface.  To reduce the servo writing time, special timing
control or staggered servo has been used but it has a disadvantage of
stability of servo on head changing.

     The above problem can be solved by allowing all heads to be
selected simultaneously so that servo data is written on all disk
surfaces simultaneously.  To achieve this function, a new line called
'Select All' is added to a conventional head control circuit as shown
in the drawing.  This circuit comprises a write driver 10 and a head
selector 12.  The Select All line is connected to the write driver 10
and the head selector 12.  In normal operations, the head selector 12
selects one of N heads 1-N by decoding an encoded head select signal
on head select lines.  (If the number N of heads is eight, at least
three head select lines are required.) When the servo data is to be
written on all disk surfaces, the Select All line is made active.
This enables the head selector 12 to select all heads 1-N
simultaneously and the write driver 10 to provide N times of a normal
write current to keep the same current for each head.  As a result,...