October/3/1987




		 WESTERN DIGITAL CORP. AT FORMAT ROUTINE

			     WDFMT   2.10





    WDFMT can be used on any Western DIgital AT Disk Controller to perform
    any of the following tasks.

	    FORMAT	   do  a low level format of the disk. This will
			   remove all data from the drive!!!

	    VERIFY	   verify the entire disk.

	    BAD TRACK	   mark  bad  tracks that  were found
			   and/or enter the bad track map.

	    SURFACE TEST   perform a surface test of the disk. This will
			   remoxe all data from the drive!!!

    In order to format a drive, one must complete the following steps;

	  1)  Enter drive parameters when prompted by the program
	      or at the DOS command line as shown below.

     WDFMT  drive#   #cyls  #head  #sectors  interleave  precomp-cyl skew

	  2)  Select the FORMAT option from the main menu and press <CR>.

	  3)  When the format is complete select the VERIFY option from
	      the main menu.

	  4)  When the verify is complete,  select the BAD TRACK option
	      from  the  main  menu.  The program  will  give a list of
	      bad tracks found	and ask if the tracks  should be marked
	      as bad. Next, the user is asked to enter the manufacturer
	      bad track map.

	  5)  If a surface test  is  desired  this can	be  done now by
	      selecting  SURFACE  TEST	from  the  main menu.  When the
	      test  is	complete,  the	user  should  return to the BAD
	      TRACK option to mark bad tracks found.

    WDFMT can keep track of 300 errors at a time. If more than 300 errors
    are found and are to be marked bad,  the user will have to repeat the
    VERIFY/SURFACE TEST followed by the BAD TRACK for each group of 300.




    In the drive parameter list the user is asked about skew. Skew is the
    shifting of sectors  in  a	track relative to an ajacent track in the
    same cylinder. Below is an example of a skew of 3.

	 head 0 :   1  2  3  4	5  6 . . . 13 14 15 16 17
	 head 1 :  15 16 17  1	2  3 . . . 10 11 12 13 14
	 head 2 :  12 13 14 15 16 17 . . .  7  8  9 10 11
	 head 4 :   9 10 11 12 13 14 . . .  4  5  6  7	8

    In the drive parameter list the user is asked about alternate sector.
    If alternate sector is enabled the formatter will create an alternate
    sector that will be used if one sector is found to	be bad during the
    verify  or	surface test.  When using this option one less sector per
    track will available  to  DOS i.e. if you enter 35 sectors per  track
    the formatter will format sectors 1 through 34 and sector 0.