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                                   WD1007A-WAH
                               System Installation
     
     CONFIGURING YOUR DRIVE
     
     In order to use an ESDI drive in any system, you must perform the 
     following three steps:  Low-level formatting the drive using WDFMT, a 
     third party software, or the WD1007A BIOS; perform active drive 
     partitioning, using MSDOS 3.3 (FDISK) or other operating systems that 
     allow partitioning, such as SCO XENIX; and, high-level formatting 
     using the operating system's normal "Format C: (or D:)/S" command.
     
     1.   BIOS:  There are two types of BIOS ROMs which may be used to 
     configure ESDI drives using the WD1007A-WAH.  The system BIOS refers 
     to the BIOS on the computer motherboard.  The system BIOS may only be 
     used if it contains the exact physical drive parameters of your 
     drive.  Most of the older model system BIOS ROMs do not contain ESDI 
     drive parameters.  The best way to determine whether your particular 
     system BIOS will support your ESDI drive is to contact your system 
     manufacturer.   If you determine that your system BIOS does support 
     your ESDI drive, you may proceed to performing a low level format by 
     using your operating system or the WDFORMAT utility.
     
     The WD1007A-WAH BIOS includes the drive parameters of most ESDI type 
     drives.  If you are using the WD1007A-WAH BIOS, you may proceed to 
     the low level formatting routine.  You may elect to low level format 
     with the WD1007A-WAH BIOS or use the WDFORMAT utility.  Both of these 
     options are included under the System Installation.
     
     
                               System Installation
     
     ...WARNING..................WARNING......................WARNING...
     
                    THE FOLLOWING LOW-LEVEL FORMAT PROCEDURE
                    WILL DESTROY ALL DATA ON YOUR HARD DRIVE
                      BACK-UP THE DATA ON YOUR DRIVE BEFORE
                    CONTINUING WITH LOW LEVEL FORMAT ROUTINE
     
     
     Before you can complete the low level formatting routine, you will 
     need to know the parameters of your hard disk drives.  As a 
     convenience to you, we have included a list of the most common hard 
     disk drives and their parameters.  To access this list, return to the 
     Storage Controller menu.  If your drive is not listed, contact your 
     drive manufacturer or consult your drive manual to determine drive 
     type and parameters.
     












     USING THE WD1007A-WAH BIOS
     
     1.   Before using the BIOS, make sure the proper address range is 
     selected on W1 and W2.  Confirm that the BIOS is enabled (jumper on 
     W3).
     
     2.   Enter the BIOS routine through the DOS DEBUG utility.  Execute 
     the DEBUG utility and at the program prompt "-" type:
     
                      G=C800:5 <CR>
     
     Depending upon the settings of W1 and W2, this causes the system to 
     execute proram code stored at location 5 in ROM.  The BIOS then tries 
     to read the parameter tables from the drive and store them in the 
     shadow RAM.  If the drive has not been formatted, the BIOS will 
     return a message of "drive not initialized".  You will see the 
     following screen:
     
          **Western Digital 1007A-WA2 Initialization Utilities, Rev. 1.0**
          
          PRESENT DRIVE SETUP...+ or - to change. <ENTER for selection
          
          DRIVE 0 CYLINDERS XXX HEADS XX PRECOMP CYLINDER XXX SPT XX
          
          DRIVE 1 CYLINDERS XXX HEADS XX PRECOMP CYLINDER XXX SPT XX
          
          
          Change Drive Types   --->1
          Low Level Format     --->2
          Surface Analysis     --->3
          Verify Drive         --->4
          Enter Defect List    --->5
          Exit and Reboot      --->6
          Enter Choice (1-6)   --->
          
     3.   To execute a function, simply enter the number of the desired 
     routine.  The BIOS wil execute that routine and then prompt you to 
     press a key to return to the main menu.  NOTE THAT ALL CHANGES MADE 
     WHILE IN THE BIOS WILL ONLY BE FINALIZED AFTER A PROPER EXIT THROUGH 
     FUNCTION 6.
     
          a.  Drive type routine
     
          The drive types can be changed by using the "+" and "-" keys.  
          Assuming that all the ESDI drives in question are specified at 
          34 sectors per track (SPT), there are four possible choices that 
          can be implemented for a drive:
          
          No drive present.  The BIOS automatically selects a drive type 0 
          if there is no drive present.  You will see the message "***NONE 
          selected or no drive present!***" next to the drive number.
          
          A selection with 17 sectors per track.  Use this feature when 
          the drive is being used in a system that does not recognize 
          drives with sectors per track values other than 17 sectors per 
          track.  The low-level format will be at 35 sectors per track, 
          while the parameter tables created will show 17 sectors per 
          track (with translation enabled).
          
          A selection with 34 sectors per track.  Use this feature if the 
          system recognizes the standard 34 sectors per track drive.
          




     
     A selection with 63 sectors per track.  Use this feature only when 
     the drive in question has more than 1024 cylinders.  Translation 
     should always be enabled when such a condition exists.  Translation 
     provides full use of all the cylinders of the drive, even though most 
     types of AT BIOS recognize only a maximum of 1024 cylinders.
     
     b.  Low Level Format Routine
     
     Formatting routines are present to do the low-level initialization of 
     the disk surface.  The drive is formatted at 35 sectors per track.  
     Transparent to the user, the routine formats with a sector skew and 
     also formats a spare sector on each track.  The surface analysis 
     routines use the spare sector when reallocating a bad sector on a 
     track.  It is also used to store the parameter information generated 
     by the BIOS.  This information is written to the spare sector on the 
     cylinder 0, head 0.  The sector skew, which is fixed at two, allows 
     the controller to maintain a 1:1 interleave across all head 
     boundaries.  Sector skewing is a method of formatting in which the 
     sector numbers are rotated in the interleave table for each track.
     
     c.  Surface Analysis Routine
     
     The surface analysis routine identifies bad tracks on the drive and, 
     in the event that there is only one bad sector on the track (and it 
     is NOT sector zero), it uses the alternate sector when reformatting 
     the track.  This prevents the controller from identifying the track 
     as "bad", providing that you have entered the manufacturer's list of 
     "bad tracks" prior to performing this routine.
     
     d.   Verify Drive Routine
     
     The verify routine identifies all the bad tracks on the drive and 
     lists them by head and cylinder number.  Use the FDISK and FORMAT 
     utilities to prepare the drive.
     
     e.   Enter Defect List Routine
     
     This routine allows you to enter the list of bad tracks as listed by 
     the drive manufacturer on the drive.
     
     
























     
     4.   If using a 5 Mbit per second ESDI drive, disable the 1007A 
     translation feature (install jumper at W8 and W14).  This type of 
     ESDI drive is always configured at 17 sectors per track.
     
     5.   Partition your hard disk drives  by following the partitioning 
     instructions with your operating system.
     
     6.   Complete high-level format routine using the "Format C: (or 
     D:)/S" command in your operating system.
     
     
     
                                LOW LEVEL FORMAT
     
                               USING WDFMT UTILITY
     
     Western Digital provides a low-level format utility that allows you 
     to prepare the drive for use by the system.  You may elect to use 
     this utility to perform the low-level formatting routine, if your 
     system BIOS supports ESDI type drives.  The program includes routines 
     for low-level formatting, disk verify, surface analysis and bad track 
     entry.  When using the 1007A board, use a 1:1 interleave, a skew of 
     2, and format the drive at 35 sectors per track with an alternate 
     sector.  WDFMT 2.10 presents the following display:
     
                        ***Western Digital Corporation***
                             AT Disk Format Utility
                                    Rev. 2.10
     
                          Current drive parameters are:
     
                      Drive (0/1)           :                 0
                      Cylinders             :                 615
                      Heads                 :                 4
                      Sectors               :                 17
                      Interleave            :                 3
                      Precomp               :                 306
                      Skew                  :                 0
                      Alt Sector            :                 No
                      
                        
                                ENTER MENU CHOICE
     
                Format disk      CAUTION this will destroy all
                                 data on drive!
                
                Verify disk
                Bad sector
                entry
                Surface test      CAUTION this will destroy all
                                  data on drive!
                Quit
                 
     











                                 SECTOR SKEWING
     
     Sector skewing is a method of formatting a drive by which sector 
     numbers are rotated in the interleave table each time a new head on a 
     cylinder is formatted.  Selecting a skew of 2 causes the first sector 
     after index on Head 0 to be identified as Sector 1.   The sector 
     identified as Sector 1 on Head 1 is the third physical sector from 
     index as shown in the following example:
     
     Example:  Ten sectors per track with a skew of 2 and 1:1 interleave:
     
          Head                        Sector Numbers
          
          0                   1  2  3  4  5  6  7  8  9  10
          1                   9 10  1  2  3  4  5  6  7  8
          2                   7  8  9 10  1  2  3  4  5  6
          
          
     This formatting procedure allows the controller to maintain 1:1 
     interleave when reading across the head boundary.  This becomes 
     critical when the number of sectors per track increases and the time 
     allowed for completion of overhead functions decreases.  By changing 
     the sector numbers, the controller has enough time to complete needed 
     tasks and be ready to read the ID field of the first sector on the 
     next head.
     
     The minimum sector skew factor for proper performance of the WD1007A 
     is 2.  Different applications may require different skew factors to 
     optimize performance.
     
                                  SPARE SECTOR
     
     WDFMT 2.10 also provides the ability to format a spare sector on the 
     track.  This spare sector is identified as Sector 0, making it 
     invisible to the system BIOS which expects sector numbers starting at 
     1.  This sector is always formatted as the last physical sector on 
     the track.  The surface analysis portion of WDFMT uses the spare 
     sector if an error is encountered with any sector on a track.  The 
     program reformats the track, numbering the bad sector as zero and 
     shifting the following sectors one to the right.  If more than one 
     sector is bad, the entire track is marked as bad when reformatted.
     
     This feature is useful since many system BIOS ROMs support ESDI 
     drives that have 34 sectors per track.  The spare sector option 
     causes the drive to look like it has only 34 sectors while providing 
     a spare sector for bad sector reassignment.  Software drivers can 
     also make it possible to utilize the spare sector for storing custom 
     data.
     
     Partition your hard disk drives  by following the partitioning 
     instructions with your operating system.
     
     Complete high-level format routine using the "Format C: (or D:)/S" 
     command in your operating system.
     











     
                                 Troubleshooting
     
     Problem:   1790 Disk 0 Error.
     
     Cause:     No low level format on hard disk.  Wrong drive type
                selected. Not enough drive power.  Bad cables. Improper
                drive selection or termination.
     
     Problem:   Drive does not partition.
     
     Cause:     Check drive types.  Note that drive types for the AT
                and AT-compatibles differ.
     
     Problem:   "Error Reading Fixed Disk" appears when booting from
                hard drive.
     
     Cause:     DOS partition not active.
     
     Problem:   Winchester activity LED continuously lit.
     
     Cause:     No problem.  Drive LED selected for latched mode.
     
     Problem:   For systems with two drives, both Winchester activity
                LEDs light at the same time.
     
     Cause:     Improper drive selection or termination. Inspect the 
                drive cables. If the data cables are straight, then set
                drive C's drive select switches for drive select 1 and
                drive D's drive select switches for drive select 2. If
                the data cables have a twist, set both drives' select
                switches for drive select 2. Consult your drive manuals
                or dealer for drive switch settings. Finally, under no
                circumstances, use twisted floppy cables for the
                Winchester drive. Floppy and Winchester drive interface
                connections differ significantly.
     
     Problem:   Slow and inefficient operation.
     
     Cause:     The typical cause for this problem is an 
                incorrect interleave factor.  Therefore, some 
                experimentation with the interleave factor may be 
                necessary. (Refer to the format instructions for setting 
                interleave factor).  Interleave factors are very dependent 
                on the host operating system and application.