
D P - 3 2 2 1 W D         C A P E L L A    AVASTOR
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/SLIMLINE         Cylinders    4125|     |     |
Capacity form/unform  2206/ 2812 MB        Heads           8|     |     |
Seek time   / track   8.0/ 1.0 ms          Sector/track     |     |     |
Controller           SCSI2 DI/WI/FAST      Precompensation
Cache/Buffer          1024 KB SEGMENTED    Landing Zone
Data transfer rate    5.400 MB/S int       Bytes/Sector      512
                     20.000 MB/S ext SYNC
Recording method     RLL 1/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 55    |    -40 66
Power: sleep              W     Humidity     %        10 90    |      8 95
       standby            W     Altitude    km                 |
       idle           6.1 W     Shock        g        10       |
       seek           7.0 W     Rotation   RPM      5400
       read/write         W     Acoustic   dBA        35
       spin-up            W     ECC        Bit   198BIT REED SOLOMON
                                MTBF         h     800000
                                Warranty Month        60
Lift/Lock/Park     YES          Certificates     CSA,UL1950,VDE



**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
QUANTUM  VP31110/32210 CAPELLA  PRODUCT MANUAL 81-108335-01 4/1995


  +---------------------------------------------------------+
  |  VP31110/32210S                         +--+            |XX
  |                                         +--+TERMPWR     |XXI
  |                                             HEADER PINS |XXN
  |                                                         |XXT
  |                                                         |XXE
  |                                                         |XXR J1
  |                                                         |XXF
  |                                                         |XXA
  |                                                         |XXC
  |                                                         |XXE
  |+-+                                                      |XX
  || |                                                      |XX
  || |Option                                                |XX
  || |J3                                                    |
  |+-+                                                      |XX Power
  |                                                         |XX J2
  +---------------------------------------------------------+






  +---------------------------------------------------------+
  |  VP31110/32210W/WD                      +--+            |XXI
  |                                         +--+TERMPWR     |XXN
  |                                             HEADER PINS |XXT
  |                                                         |XXE
  |                                                         |XXR
  |                                                         |XXF J1
  |                                                         |XXA
  |                                                         |XXC
  |                                                         |XXE
  |                                                         |+-+
  |+-+                                                      || |Option
  || |                                                      || |
  || |Option                                                || |
  || |J3                                                    |+-+
  |+-+                                                      |XX Power
  |                                                         |XX J2
  +---------------------------------------------------------+


  +---------------------------------------------------------+
  |  VP31110/32210R                                         |
  |                                                         |
  |                                                         |
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX J1
  |                                                         |XX RAID
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX
  |                                                         |XX
  | * FAULT LED                                             |XX
  |                                                         |XX
  |                                                         |
  |                                                         |
  | * BUSY LED                                              |
  +---------------------------------------------------------+









 50-pin SCSI Connector (8-bit)
 -----------------------------
      +------------------------------------+
      |       Back View                    |
      |                                    |
      +------------J1----------------J2----+
      |+------------ ------------++-------+|
      ||oooooooooooooooooooooooo1||O O O O||
      ||oooooooooooooooooooooooo2||       ||
      |+-------------------------++-------+|
      +-----------SCSI-------------Power---+
      +                                    +


      +------------------------------------+
      |       Front View (Bezel End)       |
      |                                    |
      |                                    |
      +------------------------------------+
      +--+----------+----------------------+
      |  |ooo oooooo20                     |
      +  |oooooooooo|                      +
         +1---------J3 Option
                       Connector


 68-pin SCSI Connector (16-bit)
 ------------------------------

      +--------------------------------------------------+
      |       Back View                                  |
      |                                                  |
      +------------J1------------------------------J2----+
      |+-------------------------+ +---Option--++-------+|
      |34ooooooooooooooooooooooo1| |o o o o o 1||O O O O||
      |68ooooooooooooooooooooooo35 12 o o o o o||       ||
      |+-------------------------+ +-----------++-------+|
      +-----------SCSI---------------------------Power---+
      +                                                  +


      +--------------------------------------------------+
      |       Front View (Bezel End)                     |
      |                                                  |
      |  Fault LED                                       |
      +--+-----------------------------------------------+
      +--+---+-------+-----------------------------------+
      |  |   |o ooooo|Secondary Option                   |
      +  |   |ooooooo|Connector                          +
         |   +1--J3--+
         Busy LED



 80-pin SCSI Connector (Raid)
 ----------------------------
      +--------------------------------------------------+
      |       Back View                                  |
      |                                                  |
      +--------------------------------------------------+
      |   +-----------------------------------------+    |
      |   |                                         J1   |
      |   +-----------------------------------------+    |
      +----------Combination-Connector-------------------+
      +                                                  +



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
QUANTUM  VP31110/32210W/WD CAPELLA  PRODUCT MANUAL 81-108335-01  4/95

 Jumper Setting
 ==============

 TERMPWR (Terminator Power)
 --------------------------
 Generally, the host is the only device on the SCSI bus required to
 provide TERMPWR for the bus. To ensure that there is a sufficient
 level of power along the entire SCSI bus, Digital Equipment
 Corporation recommends that all devices on the SCSI bus supply
 TERMPWR (if they are capable). SCSI devices are protected by a diode
 or similar semiconductor to prevent back flow of the terminator
 power when more than one device supplies this power.

 NOTE
 Model VP31110R/32210R drives do not supply TERMPWR. The SCA connector
 does not accommadate this feature.

     SCSI Connector
    XXXXXXXXXXXXXXXXXX
   +-------------------
   |
   |
   | o X
   |

 Configure the following model drives to provide TERMPWR by installing
 the jumper as shown: VP31110/32210-W/WD


 SCSI Bus Termination
 --------------------
 Both ends of the SCSI bus cable must be terminated. One end is
 terminated at the host. The other end must be terminated by the last
 SCSI device on the SCSI bus.

 NOTE
 Model VP31110/32210WD/R drives cannot provide bus termination.

 When the Model VP31110/31110W and VP32210/32210W drive is the last
 device on the SCSI bus, configure the drive to provide bus
 termination.


 VP31110W/32210W Bus Termination
 -------------------------------
 Configure Model VP31110W/32210W drives to provide bus termination by
 installing the three termination resistor pack SIPs on the PCBA.
 Note the orientation of pin 1 of the resistor pack (shaded or marked
 area of SIP).

  SCSI                              Power
  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXX
 +------------------------------------------+
 |        xxxxxxxxxxxxxxx1                  |
 |       xxxxxxxxxxxxxxx1                   |
 |      xxxxxxxxxxxxxxx1                    |  VP31110W/32210W
 |  +-+      +---------+                    |
 |  |:|TERMPWR        Termination SIPs
 |  +-+Header
 |


 SCSI ID (Address) Selection
 ---------------------------
 Each device on the SCSI bus must have a unique SCSI ID number
 assigned to it.

 ID number for VP31110/32210 models (8-bit SCSI) range from 0 through
 7. For W/WD models (16-bit SCSI), the numbers range from 0 through
 15.

 SCSI ID numbers for R models range from 0 through 7 for 8-bit
 configurations and from 0 through 15 for 16-bit configurations.

 Configure the SCSI ID of VP31110/32210-W/WD models by installing
 jumper across the indicated Option connector pins. For R versions,
 provide the proper open or ground signal input to the referenced pins
 of the drive's 80-pin RAID connector.


 SCSI ID - VP31110/32210W/WD 16-bit
 ----------------------------------
 +---+--+----+
 |o o o o o 1|
 |o o o o o o| Option Connector
 12--+--+----+


 SCSI ID - 16-bit drives
 -----------------------
   +----------+-------------------------------+
   | SCSI ID  |       Jumper Location         |
   |          |             PINS              |
   |          |  7-8  |  5-6  |  3-4  |  1-2  |
   +----------+-------+-------+-------+-------+
   |    0     | OPEN  | OPEN  | OPEN  | OPEN  |
   +----------+-------+-------+-------+-------+
   |    1     | OPEN  | OPEN  | OPEN  | CLOSED|
   +----------+-------+-------+-------+-------+
   |    2     | OPEN  | OPEN  | CLOSED| OPEN  |
   +----------+-------+-------+-------+-------+
   |    3     | OPEN  | OPEN  | CLOSED| CLOSED|
   +----------+-------+-------+-------+-------+
   |    4     | OPEN  | CLOSED| OPEN  | OPEN  |
   +----------+-------+-------+-------+-------+
   |    5     | OPEN  | CLOSED| OPEN  | CLOSED|
   +----------+-------+-------+-------+-------+
   |    6     | OPEN  | CLOSED| CLOSED| OPEN  |
   +----------+-------+-------+-------+-------+
   |    7     | OPEN  | CLOSED| CLOSED| CLOSED|
   +----------+-------+-------+-------+-------+
   |    8     | CLOSED| OPEN  | OPEN  | OPEN  |
   +----------+-------+-------+-------+-------+
   |    9     | CLOSED| OPEN  | OPEN  | CLOSED|
   +----------+-------+-------+-------+-------+
   |   10     | CLOSED| OPEN  | CLOSED| OPEN  |
   +----------+-------+-------+-------+-------+
   |   11     | CLOSED| OPEN  | CLOSED| CLOSED|
   +----------+-------+-------+-------+-------+
   |   12     | CLOSED| CLOSED| OPEN  | OPEN  |
   +----------+-------+-------+-------+-------+
   |   13     | CLOSED| CLOSED| OPEN  | CLOSED|
   +----------+-------+-------+-------+-------+
   |   14     | CLOSED| CLOSED| CLOSED| OPEN  |
   +----------+-------+-------+-------+-------+
   |   15     | CLOSED| CLOSED| CLOSED| CLOSED|
   +----------+-------+-------+-------+-------+

 The following optional features can be configured according to your
 system requirements. These features are model-dependent and include:

 - Spindle Synchronization

 - Write protection (not supported on R Models)

 - Spin delay


 Spindle Synchronization
 -----------------------
 Capella disk drives support synchronized spindle operation. Master
 or slave synchronized operation is set through a SCSI Mode Select
 Page.

 When the drive operates as a Master, it generates a spindle
 synchronization reference signal (SPINDLE_SYNC_REF L). When operating
 as a slave, the drive synchronizes its spindle according to the
 SPINDLE_SYNC_REF L input reference. The drive always maintains local
 speed regulation when no reference signal is applied.

 NOTE
 The reference signal must originate from drives with the same
 electronics modules. Fo example, connect Model VP31110 drive only
 with another VP31110 or VP32210 drive. Do not connect the
 SPINDLE_SYNC_REF L signal to that of any other series disk drive or
 the drive may malfunction.
 When connecting multiple drives together for spindle synchronization,
 be sure to use proper cabling techniques to avoid ground loop
 problems.

 For Model VP31110/32210 drives (except SCA), pin 10 (Option
 connector) is provided as an alternate SPINDL_SYNC_REL L connection
 to facilitate installations where a 10-pin header is used to connect
 several remote features. Pin 19 is provided to permit the use of a 2-
 pin connector for SPINDL_SYNC_REF L connections. The ground return
 is pin 20, although pins 2, 4, or 6 can be used for the ground
 return.


         +--- LOGIC_GND L
    +2-----------14
    |o   o o o o o|
    |o o o o o o o| Secondary Option Connector
    +1------------+
         +--- SPINDL_SYNC_REF L


 Write Protection 16-bit Drives, except SCA
 ------------------------------------------

 +2-----------14
 |o   o X o o o|
 |o o o X o o o| Secondary Option Connector
 +1------------+

 To write protect the drive, install a jumper across Secondary Option
 connector pins 7 and 8. To disable write protection, remove the
 jumper.


 Spin Up Power On
 -----------------
 Atlas drives have three Spin-Up on Power On modes:

 - Option 1
   Spin up occurs immediately when power is applied

 - Option 2
   Drive spins up occurs after a predetermined delay following power
   on. The delay is equal to a user-specified multiplier, multiplied
   by one plus the numerical SCSI ID of the drive.

 - Option 3
   Drive spin up is controlled by the START STOP UNIT command.


 +2-----------14
 |X   o o o o o|
 |X o o o o o o| Secondary Option Connector
 +1------------+

 For Option 1, immediate spin up power on, install the jumper across
 pins 1 and 2 of the Secondary Option connector.

 For Option 2, spin up after a delay, install the jumper across pins
 1 and 2 of the Secondary Option connector. Set delay parameters in
 the MODE SELECT command, Quantum (Vendor) Special Function Control
 Page.

 For Option 3, spin up controlled by the START STOP UNIT command,
 remove the jumper (if present) from across pins 1 and 2 of the
 Option connector.


 Remote Features
 Capella Series drives support the following remote features, which
 can be configured at the drive's Option connector or RAID backplane:

 - Remote SCSI ID selection

 - Remote LED status display


 Remote SCSI ID Selection
 ------------------------
 The SCSI ID can be set remotely from an external (remote) switch or
 control panel. For Model VP31110/31110W/31110WD drives and Model VP
 32210/32210W/32210WD drives, this is accomplished using the Option
 connector. For Model VP31110R/32210R drives, the outputs of remote
 or external ID switches at the RAID system backplane take the place
 of jumpers.

 Configure drives for remote ID selection by removing the SCSI ID
 jumpers (if present) from the SCSI ID pins. Then connect the leads
 from the external selection switch to the referenced pins. Observe
 the following guidelines while doing so.

 - ID bit 0, at Pin 1, is the Least Significant bit.

 - SCSI ID bits 0, 1, 2, and 3 are active LOW signals. That is, the
   bit is a 1 if the corresponding remote switch is closed to ground.

 - For 16-Bit drives, use pin 10 for the common ground return of all
   four ID bits. Do not use pins 2, 4, 6, or 8 as a common ground
   return. Pin 2, 4, 6, and 8 are reserved as outputs or future
   outputs.

 +---+--+----+
 |o o O O O O|
 |o * o o o o| Option Connector
 12--+--+----+

 * LOGIC_GND L (Pin 10)
 O SCSI ID <0>, <1>, <2>, <3> L
   (Pins 1, 3, 5, 7)


 Remote LED Status Display
 -------------------------
 Busy and Fault status for Model VP31110/32210-W/WD drives can be
 monitored remotely by connecting a remote Busy and a remote Fault
 display LED to the drive's Option connector or secondary Option
 connector. R Model drives provide the output, ACTIVITY LED OUT,
 which can be used to drive a user-supplied remote LED.

 Busy status is monitored remotely by connecting the cathode side of
 the remote Fault LED to the FLT_OUT L pin. The anode side of the LED
 connects to the +5 VDC OUT pin.

 Fault status can be monitored remotely by connecting the cathode side
 of the remote Fault LED of the BSY_OUT L pin. The anode side of the
 LED connects to +5 VDC OUT pin.

              +---- FLT_OUT L
 +2-----------14
 |o   o o o o o|
 |o o o o o o o| Secondary Option Connector
 +1------------+
            | +---- +5 VDC OUT
            +------ BUSY_OUT L

 NOTE
 As an alternative connection the remote Busy LED and the remote Fault
 LED can be connected to the drive using the 12-pin Option connector.
 However, shunt jumpers to configure the SCSI ID cannot be used when
 remote LED's are connected to the 12-pin Option connector. In this
 case, you must run a cable from the Option connector to a remote
 location and set up the SCSI IDs using switches or remote jumpers.

   + +5 VDC OUT
   |
  +-----------+
  |* o o o o 1|
  |o o * o o *|
  12----------+
       |     +-- FLT_OUT L
       |
       +----BSY_OUT L



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
QUANTUM  VP31110/32210 CAPELLA  PRODUCT MANUAL 81-108335-01  4/1995

 Notes on installation
 =====================

 Drive mounting
 --------------

     horizontally             vertically
   +-----------------+   +--+             +--+ +------------------+
   |                 |   |  +-----+ +-----+  | |                  |
   |                 |   |  |     | |     |  | |+----------------+|
 +-+-----------------+-+ |  |     | |     |  | ||                ||
 +---------------------+ |  |     | |     |  | ||                ||
                         |  |     | |     |  | ||                ||
                         |  |     | |     |  | ||                ||
 +---------------------+ |  +-----+ +-----+  | ||                ||
 +-+-----------------+-+ +--+             +--+ ||                ||
   |                 |                         ||                ||
   |                 |                         ||                ||
   +-----------------+                         ||                ||
                                               ++----------------++

 You can mount the disk drive in any position. LR models mount in RAID
 storage subsystems. The drive (with bezel) attaches to the system bay
 and accept #6-32 screws. Screws should not exceed 0.25 inch
 (6.25 millimeters) in length, otherwise damage to the PCB may result.


 Combination Connector - 8-bit
 ------------------------------
  +-----------------+-----------------------------------------------+
  | Part Number     | Vendor                                        |
  +-----------------+-----------------------------------------------+
  | 12-41254-01     | Quantum                                       |
  +-----------------+-----------------------------------------------+
  | 87711-502       | Berg Electronics (formerly Dupont Electronics)|
  +-----------------+-----------------------------------------------+
    Includes 0.1-in pitch, 50-pin SCSI connector and 4-pin power
    connector.


 Combination Connector - 16-bit
 -------------------------------
  +-----------------+-----------------------------------------------+
  | Part Number     | Vendor                                        |
  +-----------------+-----------------------------------------------+
  | 12-43123-01     | Quantum                                       |
  +-----------------+-----------------------------------------------+
  | 87360-0003      | Molex                                         |
  +-----------------+-----------------------------------------------+
    Includes 68-pin SCSI connector, 4-pin power connector, and a
    2-mm pitch, 12-pin (2x6) Option connector.


 Option Connector - 8-bit
 ------------------------
  +-----------------+-----------------------------------------------+
  | Part Number     | Vendor                                        |
  +-----------------+-----------------------------------------------+
  | 12-36484-08     | Quantum                                       |
  +-----------------+-----------------------------------------------+
  | 954339-01-10-15 | 3M                                            |
  +-----------------+-----------------------------------------------+
  | P92-300-204-6   | AMP, Inc.                                     |
  +-----------------+-----------------------------------------------+
  | 87049-2085      | Molex, Inc.                                   |
  +-----------------+-----------------------------------------------+
    A 2-mm pitch, 19-pin (2x10) keyed (missing pin) connector


 Secondary Option Connector - 16-bit
 -----------------------------------
  +-----------------+-----------------------------------------------+
  | Part Number     | Vendor                                        |
  +-----------------+-----------------------------------------------+
  | 12-36484-09     | Quantum                                       |
  +-----------------+-----------------------------------------------+
  | P93-300-204-7   | AMP                                           |
  +-----------------+-----------------------------------------------+
  | 954339-01-07-15 | 3M                                            |
  +-----------------+-----------------------------------------------+
    A 2-mm pitch, 13-pin (2x7) keyed (missing pin) connector


 Shunt Jumper - All Models
 -------------------------
  +-----------------+-----------------------------------------------+
  | Part Number     | Vendor                                        |
  +-----------------+-----------------------------------------------+
  | 12-36482-01     | Quantum                                       |
  +-----------------+-----------------------------------------------+
  | 86730-001       | Berg Electronics (formerly Dupont Electronics)|
  +-----------------+-----------------------------------------------+
  | LPC-SPG         | Honda                                         |
  +-----------------+-----------------------------------------------+
    A 2-mm pitch shunt for configuring termination characteristics


 RAID Connector - SCA Models
 ---------------------------
  +-----------------+-----------------------------------------------+
  | Part Number     | Vendor                                        |
  +-----------------+-----------------------------------------------+
  | 12-41319-01     | Quantum                                       |
  +-----------------+-----------------------------------------------+
  | SSC80-D01       | Specialty Electronics                         |
  +-----------------+-----------------------------------------------+
  Champ 0.050 inch Series I 80-position plug


 DC Power and pin connector assignments
 --------------------------------------
      +------------+   pin 1    +12 VDC
      | 4  3  2  1 |   pin 2    +12 Volts Return GROUND
      +------------+   pin 3    + 5 Volts Return GROUND
                       pin 4    + 5 VDC


 Mounting brackets may be required when installing the drive in a
 5.25-inch form factor bay. We recommended using brackets supplied
 by Quantum Corporation to mount the drive. Otherwise, the drive's
 isolation characteristics could be compromised. A bracket kit
 including four screws is available from the Quantum Corp. The part
 number is 70-30695-01.


 CAUTION
 The placement of the drive in the computer system must permit
 sufficient air-flow to maintain drive environment temperature within
 41*CF to 131*F (+5*C to +55*C) and maintain component surface
 temperatures below the maximums.


 CAUTION
 Screw-length must not exceed 0.25-inch (6.25 millimeters); or the
 drive may be damaged (#6-32).



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
QUANTUM  VP31110/32210 CAPELLA  PRODUCT MANUAL 81-108335-01  4/1995

 Product Description
 -------------------
 The VP31110/VP32210 disk drives are 3.5-inch, low-profile, high-
 capacity, high-performance drives with formatted capacity of 1,103 MB
 or 2,206 MB. The drives feature magneto-resistive (MR) read heads
 which greatly increase the amount of storage available on a disk
 surface and significantly improves the data integrity of the read/
 write process. Drive performance reaches an average seek time of 7.9
 ms, an achievable interface transfer rate up to 20MB/s, and an
 instanttaneous media transfer rate of 46.5 to 70.9 Mb/s.

 The drives use a 512KB segmented-cache buffer for improved caching
 performance. The drives provide data integrity by using parity check-
 ing, end-to-end error detection codes (EDC) and a 198-bit error
 correction code (ECC) on each data block stored.


 Caching
 -------
 Cache is RAM used as intermediate storage between the initiator and
 the disk. System performance is improved by placing data in RAM,
 which is a higher performance memory, avoiding a disk access. Since
 most reads and writes are sequential, caching data beyond that
 actually requested yields increased throughput for most applications.


 Segmented Buffer
 ----------------
 The drive features a 512 KB segmented buffer that maximizes the cache
 hit rate for sequential read streams. The cache is organized as
 separate track line segments. Each track line segment can hold data
 from one complete track on the media, temporarily assuming the
 identity of that corresponding track for all input/output functions.

 A segment can be thought of as intermediate storage in the form of a
 ring buffer maintained in the drive's on-board RAM. When servicing a
 READ Command, the drive temporarily stores data in the ring buffer.
 When servicing a WRITE Command, the drive fetches data from the host
 and temporarily stores it in a ring buffer as well. Several SCSI DASD
 options assume the presence of this intermediate storage.

 As soon as a head arrives at a track containing requested data, the
 drive starts to read into the assigned cache track at the first byte
 after completion of the seek. The drive then reads the following
 bytes in that track and even the preceing bytes, until the cache
 track line contains a complete copy of all data stored in the
 corresponding media track. (If interrupted by a new SCSI command,
 the drive stores the appropriate pointers and completes this reading
 sequence after completing the interrupt.)


 Write Caching
 -------------
 The drive can also do write caching. With write caching, writes are
 considered complete when the data are in the drive's data cache,
 before they written on the disk. The drive is able to combine writes
 from multiple commands to deliver higher performance. It is
 recommended that the system integrator provide a non-interruptable
 source of power for optimal write caching reliability.


 Disconnect/Reconnect
 --------------------
 System throughput is improved by disconnecting the drive from the
 initiator during time-consuming physical position operations to free
 the SCSI bus for other I/O processes. The Disconnect/Reconnect
 function is controlled by the ASABET processor, greatly reducing the
 time required for the operation.

 After the drive has determined that there will be a delay, it
 disconnects from the SCSI bus by sending a SAVE DATA POINTER and
 DISCONNECT message to enter the BUS FREE phase.

 When the drive is ready to resume data transfer, it arbitrates for
 the SCSI bus. Upon winning arbitration, it reconnects to the
 initiator an dsends an IDENTIFY message via the MESSAGE IN phase.
 This revives the I_T_L nexus so the initiator can retrieve the
 correct set of data pointers for the I/O process. The initiator
 restores the active pointers to their most recent saved values, and
 the drive continues to finish the original I/O process. The enhanced
 capabilities of the ASABET processor increases throughput.

 A forced disconnect is implemented through the Mode Select Command
 (15h) Disconnect/Reconnect page (02h).


 Media Error Protection
 ----------------------
 To verify that data reads are correct, an Error Correction Code
 (ECC) is calculated and stored with each block of data written. The
 code is recalculated on readout and used to correct errors that are
 detected. The larger the ECC, the greater its correction capability.
 The Capella drives use a 198-bit ECC. This size ECC allows correction
 of up to a 73-bit error burst per data sector. In comparison,
 competitive drives may use only a 56- or 88-bit ECC with attendant
 poorer performance. In addition, an error burst of 25 bits can be
 corrected "on the fly" (by hardware) with no delay processing.


 Transfer Error Protection
 -------------------------
 Although ECC protects against faults in the media, the entire data
 path must also be protected. The drive uses end-to-end error
 detection code (EDC) to protect data from errors that may be intro-
 duced by the connecting busses, the disk controller chip, the data
 cache, or the SCSI interface.

 The EDC is computed from the data and the LBA as it arrives from the
 SCSI bus (after SCSI bus parity is checked). The EDC is written to
 disk along with the data. When a block is read, the EDC is
 recalculated and compared against the EDC that was written on disk.
 This operation protects against transfer errors introduced anywhere
 on the internal data path.


 Embedded Servo System
 ---------------------
 Embedded servo information is written in a spoke configuration, 72
 times on every track, on every disk surface. The spokes (or headers)
 consist of quadrature analog pattern and digital address data. The
 digital portion of the spoke data are read and used to locate the
 desired track, spoke, and head number. The quadrature analog signal
 portion is detected and used by a servo feedback control loop to
 precisely position the head on the track center.


 Spindle Synchronization
 -----------------------
 Spindle Synchronization is the process of causing the disk assemblies
 in several disk drives to rotate to the same address location at the
 same time. Synchronization is used in RAID (redundant arrays of
 independent devices) mass storage systems, allowing a set of disk
 drives to function as one drive.

 To accomplish this, sector 0, track 0 of each drive must be under the
 read/write heads at exactly the same time. With spindle
 synchronization, all the drives are locked to the same relative
 position.

 If all the drives are synchronized exactly, the time used to access
 one drive results in the next drive passing the correct position.
 This problem is resolved by using an offset that is the sum of the
 transmission delays of the interconnecting bus cable, data transfer
 times, and the rotational latency of the drives.

 Knowing how long it takes to set up an I/O operation and transfer
 data to a drive, the SCSI controller can send the data to one drive
 and, while that data is being transferred, set up the I/O transfer
 to the next one. When the current transfer is complete, the
 controller is ready to transfer the next, and so on.

 Spindle Synchronization is controlled by the Rigid Disk Geometry and
 (Vendor) Special Function Control pages of the MODE SELECT command.


 Special Functions
 -----------------
 Quantum has incorporated a number of unique options into the drive.
 The (Vendor) Special Function Control page is used to control these
 options. The options include:

 - Spin Delay - delays the spin-up of the drive to reduce startup
   load of system power.

 - Initiate Synchronous Data Transfer Negotiation - a toggle-type
   parameter that allows the initiator to move between asynchronous
   and synchrounous modes of data transfer.

 - Slow Cable - adds an additional delay to REQ/ACK for very long bus
   cables.

 - Force Disconnect - the drive can be forced to disconnect from the
   SCSI bus after a SCSI Command is received in order to reduce on-bus
   time. Force Disconnect works only when a typical, error-free
   command is received.

 - Spindle Sync Check Interval - specifies the time, in minutes, of
   the interval between spindle synchronization status checks.

 - Stagger Spin Delay - specifies the time in 100 ms increments of the
   delay the drive uses in the spin-up delay formula, allowing a
   series of drives to be spin up at staggered time intervals.


 Banded recording
 ----------------
 In banded recording, the disk is divided into multiple bands or
 partitions (also called notches or bit-zoned areas). Starting at
 inner band, each next outer band has a hihger recording frequency.
 The VP31110/32210 drives have 11 bands. The use of multiple-frequency
 recording greatly increases the capacity of the drive.


 Diagnostics
 -----------
 The drive has extensive diagnostic capabilities, including those
 described below:
 power-up self-test, periodic self-adjustments, and host diagnostics.


 Power-Up Self-Test
 ------------------
 The disk drive performs a self-diagnostic test immediately at power
 up. If the drive fails its self-diagnostic tests, it will report
 sense information but will not spin up.

 The drive diagnostics test the following:

 - Drive master microprocessor
 - RAM and ROM chips
 - Buffer memory
 - Gate array chips
 - Read/write encoding circuits
 - Basic servo functions
 - SCSI interface control circuits

 Following a selection time after power-on, the disk drive is able to
 respond with appropriate status and sense data to the TEST UNIT
 READY, INQUIRY, and REQUEST SENSE commands.


