
A C - 2 1 6 0 0             C A V I A R    WESTERN DIGITAL
                                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/SLIMLINE         Cylinders        | 3148|     |
Capacity form/unform  1624/      MB        Heads           4|   16|     |
Seek time   / track  12.0/ 3.0 ms          Sector/track     |   63|     |
Controller           IDE / ATA2 FAST/ENHA  Precompensation
Cache/Buffer           128 KB              Landing Zone
Data transfer rate    5.500 MB/S int       Bytes/Sector      512
                     16.600 MB/S ext PIO4
Recording method     PRML 8/9                       operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 55    |    -40 60
Power: sleep          0.6 W     Humidity     %         8 80    |      5 95
       standby        0.6 W     Altitude    km    -0.305  3.048| -0.305 12.192
       idle           5.1 W     Shock        g        10       |    150
       seek           7.7 W     Rotation   RPM      5200
       read/write     5.1 W     Acoustic   dBA        40
       spin-up       12.4 W     ECC        Bit   ON THE FLY,REED SOLOMON
                                MTBF         h     300000
                                Warranty Month        36
Lift/Lock/Park     YES          Certificates     CE,CSA,FCC,IEC950,UL1950


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WESTERN  AC32100/32500/21600  TECHNICAL REFERENCE MANUAL 79-860019-000

  +---------------------------------------------------------+
  |                                                         |XX
  |                                                         |XX J2
  |                                                         |XX Inter-
  |                                                         |XX face
  |                                                         |XX
  |                                                         |.X
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX
  |                                                         |X1
  |                                                         |+-+
  |                                                         || |J8
  |                                                         |+-1
  |                                                         |XX Power
  |                                                         |XX J3
  +---------------------------------------------------------+  1








                         J2                    J8     J3
    +39------------------------------------1++5-3-1++-------+
    |o o o o o o o o o o o o o o o o o o o o||o o o||O O O O|
    |o o o o o o o o o o   o o o o o o o o o||o o o||4 3 2 1|
  --+40------------------------------------2++6-4-2+++-+-+-++----
                                                     | | | +12V
                   (Pin 20 keyed)                    | | +- GND
                                                     | +--- GND
                                                     +----- +5V



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                      J   U   M   P   E   R   S
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WESTERN  AC32100/32500/21600  TECHNICAL REFERENCE MANUAL 79-860019-000

 Jumper setting
 ==============

 J8  Master/Slave/Cable Select Configuration
 -------------------------------------------

    +5-3-1+ Single (Neutral Position)
    |xxx o| Factory default. The jumper in this position has no effect
    |o o o| on single hard drive configurations.
    +6-4-2+


    +5-3-1+ Single Drive              +5-3-1+ Master Drive
    |o o o| Configuration             |X o o| Configuration
    |o o o|                           |X o o| (Dual Drives)
    +6-4-2+                           +6-4-2+


    +5-3-1+ Slave Drive
    |o X o| Configuration
    |o X o| (Dual Drives)
    +6-4-2+

 NOTE
 Pins 1 and 2 are reserved; do not jumper!


 The Caviar can be assigned as either a single, master, or slave
 drive.

 Caviar drives are shipped with a jumper shunt in the neutral storage
 position (across pins 5 and 3).


 Dual Installations
 ------------------
 Dual Installations require a master/slave drive configuration, where
 one drive is designated as the primary (master) drive and the other
 is designated as the secondary (slave) drive. The Caviar drive is
 compatible in dual installations with other IDE drives that support
 a master/slave configuration.


 Jumper Settings
 ---------------
 The Caviar drive has a jumper block (J8) located next to the 40-pin
 connector on the drive. The Caviar can be assigned as either a
 single, master, or slave drive.

 Caviar drives are shipped with a jumper shunt in the neutral storage
 position (across pins 5 and 3).

 Single Drive Mode - If you are installing the Caviar drive as the
 only hard drive in the system, leave the jumper in the neutral
 storage position. Jumpers are not required for single drive
 installations. Note that even with no jumper installed, the Caviar
 checks the DRIVE ACTIVE/SLAVE PRESENT (DASP) signal to determine if a
 slave IDE drive is present. If you have a dual installation (two
 hard drives), you must designate one of the drives as the master and
 the other as the slave drive. The jumper pins on the J8 connector
 need to be configured for the dual installation.


 Master Drive Mode - To designate the drive as the master, place a
 jumper shunt on pins 5-6. With the Caviar configured as the master
 drive, the Caviar assumes that a slave drive is present. The jumper
 on pins 5-6 is optional if the slave drive follows the same protocol
 (Common Access Method AT Bus Attachment) as the Caviar.


 Slave Drive Mode - To designate the drive as the slave, place a
 jumper shunt on pins 3-4. When the Caviar is configured as the slave
 drive, the Caviar delays spin up for three seconds after power-up
 reset. This feature prevents overloading of the power supply during
 power-up.


 J3   DC Power and pin connector assignments
 -------------------------------------------
      +------------+   pin 1    +12 V
      | 4  3  2  1 |   pin 2    GND
      +------------+   pin 3    GND
                       pin 4    + 5 V



 Alternate Jumper Settings for the Caviar AC32500
 ================================================
 One initial boot, some system BIOs may lock up on drives that have
 more than 4095 cylinders (driver larger than 2.1 GB). Alternate
 jumper setting have been provided for the Caviar AC32500 to overcome
 this system BIOS limitation. These jumper settings cause the drive
 to report 4095 cylinders (instead of the usual 4960) in Word 1 of the
 Identify Drive data. The true capacity is still reported in Word 54
 and Word 60-61. All other Identify Drive data remains the same.


    +5-3-1+ Single Drive              +5-3-1+ Master Drive
    |X X o| Configuration             |X o X| Configuration
    |X X o|                           |X o X| (Dual Drives)
    +6-4-2+                           +6-4-2+


    +5-3-1+ Slave Drive
    |o X X| Configuration
    |o X X| (Dual Drives)
    +6-4-2+



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                      I   N   S   T   A   L   L
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WESTERN  AC32100/32500/21600  TECHNICAL REFERENCE MANUAL 79-860019-000

 Notes On Installation
 =====================

 Orientation
 -----------
 The Caviar can be mounted in the X, Y, or Z axis depending upon the
 physical design of your system. It is recommended that the drive be
 mounted with all four screws grounded to the chassis.


 Screw Size Limitations
 ----------------------
 The Caviar is mounted to the chassis using four 6-32 screws.
 Recommended screw torque is 5 in-lb. Maximum screw torque is 10
 in-lb.

 Caution: Screws that are too long will damage circuit board
 components. The screw must engage no more than six threads (3/16
 inch). Side mounted screws should engage a maximum of .188 inches
 (3/16"). Bottom mounted screws should engage a maximum of .250
 inches (1/4").

 Grounding
 ---------
 It is recommended that the drive be mounted with all four screws in
 the side grounded to the chassis. The drive must be grounded with at
 least one mounting screw. Side mounting: Use four metal screws.
 Top face mounting: Use four metal screws.


 Determining Your Configuration
 ------------------------------
 You can configure the Caviar in one of two ways:
 1. The drive is cabled directly to a 40-pin connector on the
 motherboard, or 2. The drive is cabled to an adapter card mounted
 in one of the expansion slots in the computer.

 Both configurations use a 40-pin host interface cable.
 If you are using the Caviar drive as one of two hard disk drives in
 the computer (dual installation), you may use either configuration.
 In dual installations, you must use a 40-pin host interface cable
 with three connectors and daisy-chain the two drives to the
 motherboard or adapter card.


 Dual Installations
 ------------------
 Dual installations require a master/slave drive configuration, where
 one drive is designated as the primary (master) drive and the other
 is designated as the secondary (slave) drive. The Caviar drive is
 compatible in dual installations with other IDE drives that support a
 master/slave configuration.


 Mounting the Drive
 ------------------
 For dual installations, it is usually easier to completely install
 one IDE drive in the lower position first. The order of IDE drives is
 unimportant if you are using two Western Digital drives. As explained
 previously, one must be jumpered as the master drive and the other as
 the slave drive. When installation is complete, the drives are
 daisy-chained together.


 Cabling and Installation Steps
 ------------------------------
 Make sure your interface cable is no longer than 18 inches (including
 daisy chaining) to minimize noise that is induced on the data and
 control buses. When connecting two drives, use a daisy-chain cable
 that has three 40-pin connectors. Connectors should be placed no more
 than six inches from the end of the cable. If only one drive is
 connected, it should be placed on the end of the cable.

 Caution: You may damage the Caviar drive if the interface cable is
 not connected properly. To prevent incorrect connection, use a cable
 that has keyed connectors at both the drive and host ends.
 Pin 20 has been removed from the J2 connector. The female connector
 on the interface cable should have a plug in position 20 to prevent
 incorrect connection. Make sure that pin 1 on the cable is connected
 to pin 1 on the connectors.

 The order in which you perform the following steps will vary
 depending on your system.

 1. Attach the end of the 40-pin interface cable to the 40-pin J2
    connector on the back of the Caviar hard drive. For dual
    installations, connect the two drives together by using a
    three-connector interface cable. Match the orientation of pin
    socket 1 on the 40-pin IDE cable to pin 1 on the connector.

 2. Thread the cable through the empty drive bay and slide in the
    Caviar drive.

 3. Mount the Caviar drive in the drive bay using four 6-32 screws. Be
    sure to use the correct size screws. Do not install the screws
    past six threads (3/16 inch). Screws that are too long will
    damage the Caviar drive.

 For proper grounding be sure to use ALL four screws.


 Interface Pin 39 DASP (I/O) Drive Active/Slave Present
 ------------------------------------------------------
 This open collector output is a timemuliplexed signal indicating
 drive active or slave present. At reset, this signal is an output
 from the slave drive and an input to the master drive, showing that a
 slave is present. For all times other than reset, DASP is asserted
 by the master and slave drives during command execution.



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                      F   E   A   T   U   R   E  S
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WESTERN  AC32100/32500/21600  TECHNICAL REFERENCE MANUAL 79-860019-000

 General Description
 -------------------
 The Caviar AC32100, AC32500 and AC21600 Enhanced IDE (EIDE) disk
 drives are high-performance solutions designed to meet the
 requirements of today's most powerful systems from home and business
 PC's to workstations and servers. These drives are based on our
 successful proven design concepts.

 High-speed host data transfers, advanced caching, increased
 rotational speeds, and low mechanical latency combine to give
 the AC32100, AC32500 and AC21600 the level of performance demanded by
 today's most advanced systems. These drives support host data
 transfers of 16.6 MB/s Mode 4 PIO and 16.6 MB/s Mode 2 multi-word DMA
 enabling VESA VL or PCI local bus EIDE integration.

 The AC32100, AC32500 and AC21600 offer a rotational speed of 5200 RPM
 and include CacheFlow4. CacheFlow4 offers adaptive read and write
 caching capabilities which complements the advanced caching
 capabilities of today's major operating systems. An average read seek
 time of sub 12 ms and rotational latency of 5.76 ms combine to
 provide fast mechanical access.

 The AC32100, AC32500 and AC21600 offer performance beyond that of
 the ISA bus. Optimum performance is obtained when these drives are
 integrated into a VESA VL or PCI local bus EIDE environment. System
 integration of these drives in a DOS or Windows environment requires
 either BIOS, device driver or operating system support for EIDE disk
 drives with capacities greater than 528 MB.

 The AC32100, AC32500 and AC21600 drives support advanced power
 management capabilities that can reduce power requirements over 85
 percent. All Caviar drives are preformatted (low-level) and defects
 are mapped out before shipment. Additional Caviar features include
 logical block addressing, linear logical/physical universal address
 translation, automatic head parking, embedded servo control data on
 each track, and ECC on-the-fly correction.

 Western Digital's award-winning Caviar drives are designed and
 manufactured to the highest standards of quality and reliability.
 This is demonstrated by their three-year warranty, 300,000 hours
 Mean Time Between Failure, and guaranteed compatibility.

 The Caviar AC32100, AC32500 and AC21600 drives are today's solution
 to the computer market's ever-increasing demand for higher
 performance and expanded connectivity capability and they still
 provide the advantages of low cost, compatibility and ease of use.


 Advanced Product Features
 -------------------------
 - CacheFlow4 - Western Digital's unique, fourth-generation caching
   algorithm evaluates the way data is read from and written to the
   drive and adapts on-the-fly to the optimum read and write caching
   methods. CacheFlow4 minimizes disk seeking operations and the
   overhead due to rotational latency delays.

   CacheFlow4 includes random and sequential write cache.
   Incorporating write cache with other CacheFlow4 features enables
   the user to cache both read data as well as write data. Multiple
   writes can now be held in the cache and then written collectively
   to the hard disk later. Data is held in the cache no longer than
   the time required to write all cached commands to the disk.

  CacheFlow4 constantly evaluates not only the size of the read data
  request but the type of data request, that is, whether the
  application is sequential, random, or repetitive. CacheFlow4 then
  dynamically partitions the Caviar's 128-Kbyte DRAM buffer into
  equalsized segments and selects the appropriate caching mode for
  optimum system performance.


 - Advanced Host Transfer - The AC32100, AC32500 and AC21600 support
   Mode 4 PIO (16.6 MB/s) and Mode 2 multi-word DMA (16.6 MB/s) as
   defined by the ATA-2 standards. To achieve Mode 4 PIO burst
   transfers, hard disk drives must be able to throttle the host
   via the IORDY signal.

   Systems typically require a high-speed VL or PCI local bus in
   order to support Mode 4 PIO.

 - High-Speed DMA Capability - DMA Read and DMA Write commands are
   ATA-2-compatible and provide significant improvement in CPU
   bandwidth over conventional PIO data transfers. The system CPU
   is free to accomplish other tasks while the Caviar drive
   transfers data directly to/from system memory.

 - Power Conservation - The AC32100, AC32500 and AC21600 support the
   ATA-2 power management command set. This command set allows the
   host to reduce the power consumption of the drive by issuing a
   variety of power management commands.

 - Zoned Recording - The AC32100, AC32500 and AC21600 employ Zoned
   Recording to increase the data density on the outer tracks of the
   drive. The outermost tracks contain more sectors than the
   innermost tracks, thereby increasing the total capacity of the
   drive.

 - Block Mode - ATA-2 compatible Read Multiple and Write Multiple
   commands are supported. Block mode increases overall data
   transfer rates by transferring more data between system
   interrupts.

 - Logical Block Addressing (LBA) - The AC32100, AC32500 and AC21600
   support both LBA and CHS-based addressing. LBA is included in
   advanced BIOS and operating system device drivers and ensures
   high-capacity disk integration.

 - Automatic Head Parking - Head parking is automatic with Caviar
   drives. On power down, the heads retract to a safe, non-data
   landing zone and lock into position, improving data integrity and
   resistance to nonoperational shock.

 - Advanced Defect Management - These Caviar drives are preformatted
   (low-level) at the factory and come with a full complement of
   automatic defect management functions. Extensively tested during
   the manufacturing process, media defects found during intelligent
   burn in are mapped out with Western Digital's high performance
   defect management technique. No modifications are required
   before installation.

 - Embedded Servo Control - These Caviar drives feature an embedded
   servo concept as the means of providing sampled position feedback
   information to the head position servo system. Servo bursts are
   located along a radial path from the disk center, ensuring that
   head positioning data occurs at constant intervals. This high
   sampling rate supports the high frequency servo bandwidth
   required for fast access times as well as highly accurate head
   positioning. The embedded servo concept provides the means of
   generating accurate feedback information without requiring a full
   data surface as would a dedicated servo control concept.


 - Dual Drive Operation - These Caviar drives support dual drive
   operation by means of a "daisy chain" cable assembly and
   configuration options for master or slave drive designation.

 - Universal Address Translation - These Caviar drives provide a
   linear disk address translator to convert logical sector
   addresses to physical sector addresses which provides for easy
   installation and compatibility with numerous drive types.

 - Guaranteed Compatibility - Western Digital performs extensive
   testing in its Functional Integrity Test Lab (FIT Lab) to
   ensure compatibility with all 100% AT-compatible computers and
   standard operating systems.

 - Reed Solomon ECC On-the-Fly - The Caviar implements Reed Solomon
   error correction techniques to obtain extremely low read error
   rates. This error correction algorithm corrects errors
   on-the-fly without any performance penalties. It allows for
   hardware corrections of up to a 24-bit error span on-the-fly.

 - Automatic Defect Retirement - If the Caviar drive detects a
   defective sector while writing, it automatically relocates the
   sector without enduser intervention.


 Defect Management
 -----------------
 Every Caviar undergoes factory-level intelligent burn in, which
 thoroughly tests for and maps out defective sectors on the media
 before the drive leaves the manufacturing facility. Following the
 factory tests, a primary defect list is created. The list contains
 the cylinder, head, and sector numbers for all defects.

 Defects managed at the factory are sector slipped. Grown defects that
 can occur in the field are mapped out by relocation to spare sectors
 on the inner cylinders of the drive.


 Format Characteristics
 ----------------------
 The Caviar is shipped from the factory preformatted (low-level) with
 all the known defects mapped out. In order to be compatible with
 existing industry standard defect management utility programs, the
 Caviar supports the logical format command. When the host issues the
 Format Track command, the Caviar performs a logical version of this
 command in response to the host's interleave table request for good
 and bad sector marking or assign/unassign the sector to/from an
 alternate sector.

 If the host issues the Format Track Command during normal operating
 modes, the data fields of the specified track are filled with a data
 pattern of all zeros. The Format Track Command can be used to
 mark/unmark bad sectors, and reassign unrelocated sectors.


 Automatic Defect Retirement
 ---------------------------
 The automatic defect retirement feature automatically maps out
 defective sectors while writing. If a defective sector appears,
 Caviar finds a spare sector.


 Error Recovery Process
 ----------------------
 The Caviar has four means of error recovery:

 * ECC On-the-Fly
 * Read/Write Retry Procedure
 * Extended Read Retry Procedure
 * Extended (Firmware Assisted) ECC

 ECC On-the-Fly - If an ECC error occurs, the Caviar attempts to
 correct it on-the-fly without retries. Data can be corrected in this
 manner without performance penalty.

 Read/Write Retry Procedure - This retry procedure is used by all disk
 controller error types. If this procedure succeeds in reading or
 writing the sector being tried, then recovery is complete and the
 controller continues with the command. Each retry operation also
 checks for servo errors. This procedure ends when error recovery is
 achieved or when all possible retries have been attempted.

 Extended Read Retry Procedure - This retry procedure tries
 combinations of positive/negative track offsets, and data DAC
 manipulations to recover the data. This retry procedure is applicable
 only to read data recovery. The Read/Write Retry procedure is used
 to perform the actual retry operation. When an extended retry
 operation has been successful, the controller continues with the
 command. The controller ensures that any changes in track offset or
 data DAC settings that exist are cleared before the command
 continues.

 Extended (Firmware Assisted) ECC - If an ECC error is too large to
 correct using ECC on-the-fly, the Caviar can attempt to correct the
 error using Extended Error Correction. This allows correction of
 large ECC errors that ECC on-the-fly cannot correct. However, the
 Extended Error Correction process takes more time than ECC
 on-the-fly to return the corrected data.


 REED SOLOMON ECC On-the-Fly
 ---------------------------
 The Caviar implements Reed Solomon error correction techniques in
 hardware to reduce the uncorrectable read error rate. This allows a
 high degree of data integrity with no impact on the drive's
 performance. Because on-the-fly corrected errors do not require the
 drive's firmware to assist with error correction, they are invisible
 to the host system.

 To obtain the ECC check byte values, each byte within the sector is
 interleaved into one of three groups, where the first byte is in
 interleave 1, the second byte is in interleave 2, the third byte is
 in interleave 3, the fourth byte is in interleave 1, and so on.

 Interleaving and the ECC formulas enable the drive to detect where
 the error occurs. A maximum of one byte can be corrected in each
 interleave without firmware assistance.


 Firmware Assisted ECC
 ----------------------
 With firmware assisted ECC, a maximum of 3 bytes can be corrected in
 each interleave. In this case, a 65-bit error span is the maximum
 that is always correctable with firmware assistance because the
 entire error span will never occupy more than three bytes in each
 interleave.


 Universal Address Translation
 -----------------------------
 The Caviar implements linear address translation. The translation
 mode and translated drive configuration are selected by using the Set
 Drive Parameters command to issue head and sector/track counts to the
 translator. Caviar supports universal translation. Therefore, any
 valid combination of cylinder, head, and SPT can be assigned to the
 drive as long as the total number of sectors is not greater than the
 physical limits. The product of the cylinder, head and sectors/track
 counts must be equal to or less than the maximum number of sectors
 available to the user.

 AC21600 - 3,173,178
 AC32100 - 4,124,736
 AC32500 - 4,999,680

 Each sector consists of 512 bytes.

 The minimum value for any translation parameter is one. The maximum
 value for any translation parameter is as follows:

 Sectors/Track      -    255
 Heads              -     16
 Cylinders/Drive    - 65,535

 The values in the Sector Count Register and the SDH Register
 determine the Sectors Per Track (SPT) and heads. Regardless of the
 values of the SPT and the heads, Caviar is always in the translation
 mode.


 Power Conservation
 ------------------
 The AC32100, AC32500 and AC21600 support the ATA-2 power management
 commands that lower the average power consumption of the disk drives.
 For example, to take advantage of the lower power consumption modes
 of the drive, an energy efficient host system could implement a power
 management scheme that issues a Standby Immediate command when a
 host resident disk inactivity timer has expired. The Standby
 Immediate command would cause the drive to spin down and enter a
 low-power mode. Subsequent disk access commands would cause the drive
 to spin up and execute the new command.

 To avoid excessive wear on the drive due to the starting and stopping
 of the HDA, the host's disk inactivity timer should be set to no
 shorter than ten minutes.


 High-Speed DMA Capability
 -------------------------
 By engaging an ATA-2 compatible, Mode 2 multi-word DMA, the host CPU
 bandwidth is increased because the peripheral data transfer burden is
 off-loaded to the system's DMA channel. With the exception of DMA
 data transfers, which are limited to Read DMA and Write DMA
 commands, all other commands must be performed using PIO. DMA or PIO
 data transfer mode selection by the host is performed on a
 command-by-command basis.


 Advanced Host Transfers
 -----------------------
 The AC32100, AC32500 and AC21600 support high-speed Mode 3 and 4 PIO.
 These are data transfer modes that utilize hardware handshaking
 between the host and the drive via the IORDY signal. When the drive
 deasserts the IORDY signal, the host extends the read/write cycle
 until IORDY is asserted, thereby eliminating data corruption from
 overrun and underrun conditions. When in Mode 3 PIO, data can be
 transferred in bursts to and from the host at a rate of up to 11.1 MB
 per second; in Mode 4 PIO, the data can be transferred at a rate of
 up to 16.6 MB per second.

 Mode 3 and Mode 4 PIO are enabled on the drive by issuing a Set
 Features command. If Mode 3 or Mode 4 PIO is enabled, it can only be
 disabled by issuing another Set Features command, a hard reset, or by
 cycling power. To support Mode 4 PIO, Flow Control must be enabled in
 the host system. If this mode is enabled on a system that does not
 support Flow Control, host FIFO errors can occur.

 Mode 3 and Mode 4 PIO timings were defined to facilitate EIDE drive
 integration into VL and PCI local bus systems.


 Zoned Recording
 ---------------
 Zoned Recording is a mechanism for increasing the capacity of the
 drive by increasing the Bit-Per-Inch (BPI) density of data written
 on the longer outer tracks of the drive. Track capacity (number of
 sectors) is constant within groups of tracks or zones, and is
 increased when the tracks are sufficiently long to accommodate a
 significant number of additional sectors. This incremental increase
 in track capacity moving outward on the disk surface creates a series
 of concentric zones with different data densities.


 Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.)
 ----------------------------------------------------------------
 S.M.A.R.T. enables a drive's internal status to be monitored through
 diagnostic commands at the host level.

 The Caviar AC21600, AC32100 and AC32500 drives monitor read error
 rate, start/stop count, spin-up retry count, and drive calibration
 retry count. All of these attributes are updated and stored on the
 hard drive in the reserved area of the disk. The hard drive also
 stores a set of attribute thresholds that correspond to the
 calculated attribute values. Each attribute threshold indicates the
 point at which its corresponding attribute value achieves a negative
 reliability status.


 WESTERN DIGITAL Defect Management Utility
 -----------------------------------------
 All Caviar IDE drives are defect-free and low level formatted at the
 factory. After prolonged use, any drive, including Caviar, may
 develop defects. If you continue receiving data errors in any given
 file at the DOS level, you can use the defect management utility
 WDAT_IDE to recover, relocate and rewrite the user data to the
 nearest spare sector and maintain a secondary defect list.

 Caution: As with all format utilities, some options in the WDAT_IDE
 utility will overwrite user data.



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                      G   E   N   E   R   A   L
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WESTERN   CAVIAR  INSTALLATION GUIDE  79-850086-003 SO 225  11/98


 TROUBLESHOOTING
 ---------------
 This section lists procedures to help resolve problems that you may
 encounter when installing the Western Digital hard drive.

 - Refer to your system documentation to be sure that you followed
   the setup procedures correctly.

 - Make sure that you partitioned and formatted the EIDE drive and
   any additional drive with the EZ-Drive installation software. Refer
   to your operating system documentation to check these procedures.

 - If using DOS 3.3 and above, be certain to make one partition
   active during formatting.

 - Check the physical installation of your system to make sure that:
   - Jumper selections on the drive are correct for your installation.

   - Cables are correctly connected and seated.

   - Adapter card, if required, is properly seated, connected, and
     configured.

   - Power is properly connected to your system and the system is
     plugged in.


 Operating System and System BIOS Limitations
 --------------------------------------------
 Computer operating systems and system BIOSs have separate limitations
 that are related to specific hard drive capacities. Three capacity
 points that can affect how your operating system and system BIOS
 support your hard drive are 8.4 GB, 2.1 GB, and 528 MB. A brief
 description of these limitations follows.

 8.4 GB Barrier: There is an 8.4 GB hard drive limitations on some
 traditional system BIOSs. To access the full capacity of 8.4 GB and
 larger hard drives, your system BIOS must support extended BIOS
 functions, and your operating system must recognize extended BIOS
 functions. It is difficult to determine if your system BIOS supports
 8.4 GB or larger hard drives. We recommend using EZ-Drive 9.06W
 or later to ensure support of the full capacity of your hard drive.
 2.1 GB Barrier: Some computer systems built before early 1996 do
 not support hard drives with more than 4095 cylinders (hard drives
 larger than 2.1 GB), unless you update the system BIOS, install an
 EIDE controller card with onboard BIOS, or install third-party
 software such as EZ-Drive.

 528 MB Barrier: Most computer systems built before August 1994 do
 not support hard drives larger than 528 MB, unless you update the
 system BIOS, install an EIDE controller card with onboard BIOS, or
 install third-party software such as EZ-Drive.

 To determine if your system BIOS supports the full capacity of your
 hard drive, EZ-Drive compares the system CMOS settings to the
 actual drive size. If the values match, EZ-Drive only partitions and
 formats the hard drive; it does not install EZ-BIOS. If the values do
 not match, EZ-Drive partitions and formats the hard drive and
 installs EZ-BIOS on the boot sector of the hard drive.


 Operating System and System BIOS Limitations for 8.4 GB and
 Larger Hard Drives
 -------------------------------------------------------------
 The following is required to access the full capacity of an 8.4 GB or
 larger hard drive:

 - A system BIOS that supports extended functions

 - an operating system that recognizes extended BIOS functions

 The limitations of your system BIOS and your operating system
 combined determine your overall system limitation. For example, if
 your operating system recognizes extended BIOS functions, but your
 system BIOS has a 2.1 GB drive barrier, you are limited to your
 system BIOS's 2.1 GB drive barrier. Conversely, if your operating
 system does not recognize extended BIOS functions, but your system
 BIOS supports 8.4 GB hard drives, you are limited to your operating
 system's capability. Your system limitation is based on the lowest
 functioning barrier.

 Since it is difficult to determine if your system BIOS supports your
 8.4 GB or larger hard drive, we recommend using EZ-Drive 9.06W to
 support the full capacity of your hard drive. Another option is to
 upgrade your system BIOS. A properly upgraded system BIOS will
 support the full capacity of your hard drive if used with an
 operating system that recognizes extended BIOS functions. Contact
 your system manufacturer for more information.

 Operating systems that recognize extended BIOS functions:
 - Windows 95

 - Windows 98

 Operating systems that do not recognize extended BIOS functions.
 - DOS 6.xx and earlier

 - Windows 3.1x

 - Windows NT

 - Novell NetWare

 - OS/2 Warp

 Operating System Limitations and Exceptions
 DOS 6.xx and earlier
 Windows 3.1x
 8.4 GB maximum capacity limit. Hard drive capacities
 larger than 8.4 GB are recognized as 8.4 GB.

 Windows NT Windows NT 4.0 with Service Pack 3 supports hard
 drive capacities larger than 8.4 GB.

 Novell NetWare Novell NetWare 4.11: Drivers are available to support
 capacities larger than 8.4 GB.

 Novell NetWare 5 supports 8.4 GB and larger hard drives.

 OS/2 Warp Requires patch to support 8.4 GB or larger hard drives.


 System BIOS Limitations for Hard Drives Larger Than 2.1 GB
 -----------------------------------------------------------
 IMPORTANT
 If you installed a 2.5 GB or larger hard drive and your system does
 not respond (locks up) on initial boot, read this section.

 Hard drives larger than 2.1 GB have more than 4095 cylinders. On
 some systems, the system BIOS cannot properly recognize hard drives
 with more than 4095 cylinders.

 You will know if your system BIOS has this limitation after
 installing your drive if:

 - Your operating system shows a much smaller drive capacity than
   the actual drive capacity.

 - Your system locks up on initial boot, preventing you from accessing
   CMOS setup.


 Operating System Shows a Much Smaller Capacity
 ----------------------------------------------
 If your operating system shows a much smaller drive capacity, use
 EZ-Drive to overcome the 2.1 GB BIOS limitation.

 Your System Locks Up on Initial Boot
 ------------------------------------
 If you cannot access the CMOS setup because your system locks up
 on initial boot, follow the instructions below.

 1. Turn off your system power, check the IDE interface cable and
    power supply cable.

 2. Check jumper settings.

 3. Turn on your system power.

 4. Try to enter your CMOS setup and set the drive type to auto
    config.

 If your system still does not respond, your system BIOS may not
 support drives with more than 4095 cylinders. If this is the case,
 consider these solutions:

 A. Use EZ-Drive.
 If the system locks up and prevents entry to CMOS, you need to
 turn off your system power and disconnect the IDE interface cable
 from the system.

 - Enter your CMOS setup. Refer to your system manual for
   instructions.

 - Select the Hard Disk Type option for the new Western Digital
   hard drive. Select a user defined drive type and enter: 1023
   cylinders, 16 heads, and 63 sectors. If your system does not have a
   user defined drive type, select Type 9.

 - Reconnect your IDE interface cable to the system.

 - Run EZ-Drive or boot to the EZ-Drive 9.06W diskette.These
   new settings allow your system to boot so that you can install
   EZ-BIOS to access the full capacity of the drive.

 - OR -If you do not have a user defined or Type 9 drive type, use
   option B, C, or D below to change the parameters reported to
   the BIOS.

 B. Upgrade your system BIOS
 A properly upgraded system BIOS will support the full capacity of
 your hard drive. Contact your system manufacturer and closely
 follow their specific instructions. See page 3 for a list of common
 system manufacturers and page 12 for BIOS upgrade sources with
 their phone numbers.

 C. Install an EIDE controller card with an onboard BIOS that
 supports hard drives larger than 2.1 GB. For 8.4 GB or larger hard
 drives, the EIDE controller card must support extended BIOS
 functions.

 D. Rejumper the drive as described on the following page and install
 EZ-Drive. With these alternate jumper settings, you MUST install
 EZ-Drive. If you move this hard drive to another system, you
 must put the jumper back to the standard position.
 Note for Windows NT Users: If your system locks up, and you are
 using Windows NT, do not use these alternate jumper settings.
 You need to either use the standard jumper settings on page 2 and
 select a user defined drive type in CMOS setup or upgrade your
 system BIOS to support the full capacity of your new hard drive.

 IMPORTANT
 These alternative jumper settings DO NOT work with Windows NT, Novell
 NetWare, or Unix.

 Single Drive: If you have a 2.5 GB or larger hard drive, your system
 locks up on initial boot, and the drive you are installing is the
 only drive in your system, set the jumpers in these positions.

 Dual (Master) Drive: If you have a 2.5 GB or larger hard drive, your
 system locks up on initial boot, and the drive you are installing is
 the master drive in a twondrive system, set the jumpers in these
 positions.

 CAUTION: Use these jumper settings only if you encounter the
 specific BIOS limitation (system locks up) described in this section.
 These jumper settings cause the drive to report 4092 cylinders
 (2.1 GB) rather than the actual drive capacity. If you use these
 jumper settings, you MUST install EZ-Drive to access the full
 capacity of your new hard drive.


 Dual (Slave) Drive: If you have a 2.5 GB or larger hard drive, your
 system locks up on initial boot, and the drive you are installing is
 the slave drive in a twondrive system, set the jumpers in these
 positions.


