
S T 1 1 3 3 N S    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders    1268|     |     |
Capacity form/unform   113/  133 MB        Heads           5|     |     |
Seek time   / track  15.0/ 4.0 ms          Sector/track   35|     |     |
Controller           SCSI2 SINGLE-ENDED    Precompensation
Cache/Buffer            32 KB              Landing Zone
Data transfer rate    1.250 MB/S int       Bytes/Sector      512
                      5.000 MB/S ext SYNC
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 50    |    -40 70
Power: sleep              W     Humidity     %         8 90    |      5 95
       standby            W     Altitude    km    -0.305  3.048| -0.305 12.192
       idle               W     Shock        g         2       |     50
       seek               W     Rotation   RPM      3600
       read/write    11.5 W     Acoustic   dBA        43
       spin-up            W     ECC        Bit   48
                                MTBF         h     150000
                                Warranty Month        12
Lift/Lock/Park     YES          Certificates     CSA,FCC,UL478,VDE



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                        L   A   Y   O   U   T
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SEAGATE  ST1126/1133/1162/1186/1201/1239-N  PRODUCT MANUAL 36132-006

  Standard I/O
  ============
  +-------------------------------------------------------+
  |                                                       |XXXX Power
  |                                                 1-+   |
  |                                                 | |   |X1
  |                                    Resistor     | |   |XX
  |                                    Termination  +-+   |XX SCSI
  |                                    Packs        1-+   |XX Connec-
  |                                                 | |   |XX tor
  |                                                 | |   |XX
  |                                                 +-+   |XX
  |                                                 1-+   |XX
  |                                                 | |   |XX
  |                                                 | |   |+-1
  |                                                 +-+   || | SCSI ID
  |                                                    +-+|| |
  +----------------------------------------------------+-+++-11
                                           Termination Power






  Reoriented I/O
  ==============
  +-------------------------------------------------------+
  |                                                       |XXXX Power
  |                                                 1-+   |
  |                                                 | |   |XX
  |                                    Resistor     | |   |XX
  |                                    Termination  +-+   |XX SCSI
  |                                    Packs        1-+   |XX Connec-
  |                                                 | |   |XX tor
  |                                                 | |   |XX
  |                                                 +-+   |XX
  |                                                 1-+   |XX
  |                                                 | |   |1X
  |                                                 | |   |+-1
  |                                                 +-+   || | SCSI ID
  |                                                    +-+|| |
  +----------------------------------------------------+-+++-11
                                           Termination Power



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                      J   U   M   P   E   R   S
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SEAGATE  ST1126/1133/1162/1186/1201/1239-N  PRODUCT MANUAL 36132-006

 Jumper setting
 --------------

 J2   SCSI ID jumpers
 --------------------
 +----------------+-------+-------+-------+------+-------+-------+
 |    SCSI ID     | 11-12 | 10-9  | 8-7   |6-5   | 4-3   | 2-1   |
 +----------------+-------+-------+-------+------+-------+-------+
 |         0      |       |       |       |OPEN  | OPEN  | OPEN  |
 +----------------+-------+-------+-------+------+-------+-------+
 |         1      |       |       |       |OPEN  | OPEN  | CLOSED|
 +----------------+-------+-------+-------+------+-------+-------+
 |         2      |       |       |       |OPEN  | CLOSED| OPEN  |
 +----------------+-------+-------+-------+------+-------+-------+
 |         3      |       |       |       |OPEN  | CLOSED| CLOSED|
 +----------------+-------+-------+-------+------+-------+-------+
 |         4      |       |       |       |CLOSED| OPEN  | OPEN  |
 +----------------+-------+-------+-------+------+-------+-------+
 |         5      |       |       |       |CLOSED| OPEN  | CLOSED|
 +----------------+-------+-------+-------+------+-------+-------+
 |         6      |       |       |       |CLOSED| CLOSED| OPEN  |
 +----------------+-------+-------+-------+------+-------+-------+
 |         7      |       |       |       |CLOSED| CLOSED| CLOSED|
 +----------------+-------+-------+-------+------+-------+-------+
 |Enable Parity   |       |       | CLOSED|      |       |       |
 +----------------+-------+-------+-------+------+-------+-------+
 |Start/Stop      |       | CLOSED|       |      |       |       |
 +----------------+-------+-------+-------+------+-------+-------+
 |Ext.Spindle     | OPEN  |       |       |      |       |       |
 |Sync. Connection|       |       |       |      |       |       |
 +----------------+-------+-------+-------+------+-------+-------+

 Pin 1-2:   Least Significant Bit
     3-4:   Next Significant Bit
     5-6:   Most Significant Bit


 Start/Stop option
 -----------------
 When a jumper is installed on pins 9 and 10, the drive waits for a
 Start Unit command from the host before starting the spindle motor.
 The spindle motor is also stopped using this command.


 External Spindle Motor Synchronization
 --------------------------------------
 Note: this option is available on the ST1133N, ST1186N, ST1201N, and
       ST1239N only.


 Terminator Power Source Select
 ------------------------------
 ----+----+--PCB--  A-B        Drive Power Connector (Factory Default)
     |D  C|         A-C        Drive from SCSI Bus
     |B  A|         A-C & B-D  Drive from Power Connector and Provide
     +----+                    to SCSI Bus
                    B-D        Only Provide to SCSI Bus


 50-Pin SCSI Connector Pin Assignments
 -------------------------------------
    Signal    Pin No.    Signal     Pin No.
    ----------------------------------------
    -DB(0)       2       Ground       28
    -DB(1)       4       Ground       30
    -DB(2)       6       -ATN         32
    -DB(3)       8       Ground       34
    -DB(4)      10       -BSY         36
    -DB(5)      12       -ACK         38
    -DB(6)      14       -RST         40
    -DB(7)      16       -MSG         42
    -DB(P)      18       -SEL         44
    Ground      20       -C/D         46
    Ground      22       -REQ         48
    Ground      24       -I/O         50
    Terminator  26
    Power

  Note: All odd pins, except pin-25 are connected to ground. Pin-25
        is open.

 Caution: Pin 25 must not be connected to ground at the host end or
          the drive end of the cable. If the I/O connector should
          accidentally be plugged in upside down, terminator power
          would then be shorted to ground.

 The minus sign next to signals means that the asserted state is the
 low voltage of the two levels used for logic signals.


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



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                      I   N   S   T   A   L   L
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SEAGATE  ST1126/1133/1162/1186/1201/1239-N  PRODUCT MANUAL 36132-006

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

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

     horizontally             vertically
   +-----------------+   +--+             +--+ +------------------+
   |                 |   |  +-----+ +-----+  | |                  | x
   |                 |   |  |     | |     |  | x+----------------+x
 +-+-----------------+-+ |  |     | |     |  | ||x              x||
 +---------------------+ |  |     | |     |  | ||  x          x  ||
                         |  |     | |     |  | ||    x      x    ||
      x           x      |  |     | |     |  | ||      x  x      ||
 +------x------x-------+ |  +-----+ +-----+  | ||       xx       ||
 +-+------x--x-------+-+ +--+             +--+ ||     x    x     ||
   |       xx        |                         ||   x        x   ||
   |     x    x      |                         || x            x ||
   +---x--------x----+                         |x                x|
     x            x                           x++----------------++x
      UNACCEPTABLE!                                UNACCEPTABLE!
      Never install PC board on the Top!

 The drive may be mounted horizontally with the PC board down or on
 either side. Mounting vertically on either end is a prohibited orien-
 tation.
 For optimum performance, the drive should be formatted in the same
 position as it will be mounted in the host system.

 Do not mount the drive vertically on either end.


 Shock and vibrations
 --------------------
 All shock and vibration specifications assume that the drive is moun-
 ted in an approved orientation with the input levels at the drive
 mounting screws.

 During normal operating shock and vibration, there is no physical
 damage to the drive and performance is not degraded.

 During abnormal operating shock and vibration, there is no physical
 damage to the drive, although performance may be degraded during the
 shock or vibration episode. Drive performance will return to speci-
 fications when normal operating shock levels resume.


 Handling and Static-Discharge Precautions
 -----------------------------------------
 After unpacking, and prior to system integration, the drive may be
 exposed to potential handling and ESD hazards. It is mandatory that
 you observe standard static-discharge precautions. A grounded wrist-
 strap is preferred. Handle the drive by the frame only and always
 rest the drive on a padded surface until it is mounted in the host
 system.

 Caution: to avoid potential service problems, observe the following
 precautions:

 - Handle the drive by the edges or frame. Do not put pressure on the
   top cover or touch the circuit board.
 - Do not remove or cover factory-installed labels. They contain in-
   formation needed to service the product.
 - Do not put labels over the brather holes on the top surface of the
   drive. The breather holes must remain clear to allow air to circu-
   late.
 - If a label, other than a factory-installed label, has been placed
   over the breather holes, remove it. Do not poke holes through the
   label. This damages the filter underneath, allowing contaminants
   to enter the drive.
 - Do not use solvents to remove the adhesive residue from drive
   labels. Small amounts of solvent may get into the unit and conta-
   minate the disc.
 - Do not plug a live DC power cabel into the drive power connector.
   This damages the connector contacts.


 FCC Verification
 ----------------
 This equipment has been tested with a Class B computing device and
 has been found to comply with Part 15 of the FCC rules. These limits
 are designed to provide reasonable protection against harmful inter-
 ference in residential installations. This equipment generates, uses,
 and can radiate radio frequency energy, and if not installed and used
 in accordance with the instructions, may cause harmful interference
 to radio communications. However, there is no guarantee that will not
 occur in a particular installation.

 Caution: Any changes or modifications to the equipment by the user
 not expressly approved by the garantee or manufacturer could void the
 user's authority to operate such equipment.

 Note: This digital apparatus does not exceed the Class B limits for
 radio noise emissions from digital apparatus as set out in the radio
 interference regulations of the Canadian Department of
 communications.


 SCSI Interface
 --------------
 The interface is compatible with the mandatory subset of the ANSI
 SCSI-2 Interface Specification and the Common Command Set (CCS)
 document.

 In addition, the interface includes automatic features that relieve
 the host from the necessity of knowing the physical architecture of
 the target.

 The physical interface consists of single-ended drivers and receivers
 using asynchronous or synchronous communication protocols that
 support cable lengths of up to 6 meters and a bus interface transfer
 rate of up to 1.25 Mbytes/sec asynchronous and 5.0 Mbytes/sec
 synchronous. The drive is always a target on the SCSI bus.


 Sway
 ----
 The sway of the HDA left to right and front to rear is within the
 envelope. The sway of the HDA up and down is  .18 inches outside the
 envelope.


 SCSI Connector
 --------------
 The drive may be daisy-chained to other SCSI devices using a common
 cable. The SCSI devices at both ends of the daisy-cain are to be
 terminated. Intermediate SCSI devices shall not be terminated. All
 signals are common between all SCSI devices. The drive may be daisy-
 chained only with SCSI devices that have single-ended driver and
 receivers. A maximum of eight SCSI devices (including the Host) can
 be daisy-chained together.


 Single-Ended Drivers/Receivers
 ------------------------------
 The drive uses single-ended drivers and receivers. Terminator
 circuits should be installed only on the last drive in the daisy-
 chain.


 Cable requirements
 ------------------
 Only nonshielded cable connectors are applicate. A 50 conductor flat
 cable or 25 twisted pair cable shall be used. The maximum cable
 length is 6.0 meters. A stub length of no more than 0.1 meter is
 allowd off the mainline interconnection at any connected equipment.

 A characteristic impedance of 100    10% is recommended for un-
 shielded flat or twisted-pair ribbon cable. However, most of the
 commonly-avialable cables have a somewhat lower characteristic
 impedance. To minimize discountinuites and signal reflections, cables
 of different impedances should not be used in the same bus. If the
 same SCSI bus uses both shielded and unshielded cables, problems may
 result from impedance mismatch.

 In implementing your system, you may encounter trade-offs in
 shielding effectiveness, cable length, the number of loads, transfer
 rates, and cost to achieve satisfactory system operation.

 A minimum conductor size of 28 AWG should be used to minimize noise
 effects.


 External Spindle Motor Synchronization
 --------------------------------------
 Note: this option is available on the ST1133N, ST1186N, ST1201N, and
       ST1239N only.

 The external spindle motor synchronization option allows for synchro-
 nized rotation of multiple disc drives in a system. Drives configured
 to source a spindle clock signal are not interchangeable with drives
 configured to one of the following modes:

 Use internal spindle clock, omit spindle reference clock.

   - Use external spindle clock with a line terminator.
   - Use external spindle clock without the line terminator.

 The spindle rotation synchronization uses one of the following
 methods:

 - Reference clock is generated by the controller. All the disc drives
   are connected radially to the controller. Each end must be
   terminated.

 Reference clock is generated by a master disc drive. All disc drives
 are connected in parallel (daisy-chain) to the master disc drive. The
 master disc drive end and the last drive in the chain must be
 terminated. The cable consists of two #28 AWG wires. The maximum
 cable length is 20 ft (6.1 meters). The external spindle clock
 connector header is mounted on the disc drive main PCB. Posistion 6
 of the SCSI ID Address and Option Select Jumpers is used for the
 external spindle clock connection.

 The external spindle clock signal shares balanced differential
 drivers, balanced differential receivers and terminators with the
 data transfer section.


 Terminators
 -----------
 There are three internal drive I/O termination SIP resistor modules
 that plug into sockets on the PC board. You can order the drive with
 or without these terminators, depending on the application. All
 single initiator/single target applications require that the
 initiator and drive be terminated. Daisy-chain applications require
 that only the units at each end of the daisy-chain be terminated. All
 other peripherals on the chain should not be terminated.

 All interface signals with the drive are single-ended and must be
 terminated with 220  to   5V and 330  to ground at each end ot the
 total cable. All signals use open collector of three state drivers.

 Note: Remove terminator resistor packs where terminators are not
 required. Removal of terminator power source selection jumper does
 not disconnect the terminator resistors from the circuit.


 Terminator Power
 ----------------
 The drive can be configured to supply terminator power for the SCSI
 Bus. The drive also may be configured to accept terminator power via
 Pin 26 of the SCSI bus or to provide terminator power for optional
 internal termination resistors via the drive power connector. If
 terminators are installed, jumpers must also be installed.


 DC Power Specification
 ----------------------
 Except during the write procedure, power may be applied or removed in
 any sequence without loss of data or damage to the drive. If you turn
 off the power during the write procedure, you may lose the data
 beeing written.

 A   10% tolerance for 5 VDC and +10/-15% tolerance for the 12 VDC is
 permissible during the first 10 seconds of power up. A voltage
 tolerance of   5% must be maintained after this initial start period.



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                      F   E   A   T   U   R   E  S
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SEAGATE  ST1126/1133/1162/1186/1201/1239-N PRODUCT MANUAL 36132-006

 Introduction
 ------------
 These products are high capacity, high performance drives incor-
 porating an embedded SCSI controller.
 The SCSI Interface used in the Swift drive is compatible with the
 ANSI SCSI standard and the Common Command Set (CCS) document,
 Revision 4.B. Swift SCSI interface drives are classified as
 "intelligent peripherals." These drives provide Level 2 conformance
 with the ANSI SCSI standard.

 UL/CSA Listing
 --------------
 The Swift SCSI disc drives comply with UL 478 and UL 1950, CSA C22.2
 No. 220-M1986, VDE 0806/8.81 and EN 60 950/1.88

 VDE Listing
 -----------
 The Swift SCSI disc drives comply with VDE 0806/8.81 and
 EN 60 950/1.88


 Format capacity
 ---------------
 The sector size is user-selectable (256-4,096) at format time. The
 user may modify the sector size before issuing a format command and
 obtain different formatted capacities. User available will depend on
 the spare reallocation method selected.

 The maximum execution time for a format command is 20 minutes.


 Reliability
 -----------
 Read error rates are measured with automatic retries and data
 correction with ECC enabled and all flaws reallocated. MTBF is
 measured at nominal power, sea level, and 40*C ambient temperature.

 MTBF  150,000 power on hours
 MTTR  30 Minutes


 Seek Time Definition and Timing
 -------------------------------
 Seek time is a true statistical average (at least 5,000 measure-
 ments) of seek time less drive internal and external host overhead.
 All measurements are calculated under nominal conditions of tempera-
 ture, voltage and horizontal orientation.
 Track-to-track access time is the average of all possible single-
 track seeks in both directions. Average seek time is measured by
 executing seek in both directions between random cylinders or Logi-
 cal Block Addresses (LBA). Full-stroke access time is one-half the
 time needed to seek from LBA zero to the maximum LBA and back to LBA
 zero.

 Note: Host overhead varies between systems and cannot be specified.
       Drive internal overhead is measured by issuing a no-motion seek
       from the highest Logical Block Address. Overhead is typically
       less than 1.5
                                          |ST11**N |
        ----------------------------------+--------+
        Track-to-Track         msec. typ. |   4    |
                               msec. max. |   5    |
                       Average msec. typ. |  15    |
                       Average msec. max. |  16    |
        Full-Stroke            msec. typ. |  33    |
                               msec. max. |  35    |
        Latency                msec. avg. |   8.33 |
        ----------------------------------+--------+


 SCSI Bus
 --------
 Communication on the SCSI bus is allowed between only two SCSI
 devices at a time. There can be a maximum of eigth SCSI devices
 including the host computer(s) connected to the SCSI bus. Each SCSI
 device has a SCSI ID bit assigned. The SCSI ID is assigned by
 installing from zero to three jumper plugs onto a connector in a
 binary coded configuration during system configuration.

 When two SCSI devices communicate on the SCSI Bus one acts as an
 initiator and the other acts as a target. The initiator (typically a
 host computer) originates an operation and the target performs the
 operation. The drive always operates as a target.

 The Host Adapter/Initiator must be identified by one of the eight
 SCSI Device Addresses. When installing drives on the SCSI Bus make
 sure no drive has the same address as the Host Adapter.

 Certain SCSI bus functions are assigned to the initiator and certain
 SCSI bus functions are assigned to the target. The initiator will
 select a particular target. The target will request the transfer of
 Command, Data, Status or other information on the data bus.


 Thermal Compensation
 --------------------
 The Thermal Compensation operation compensates for thermal-related
 position offset on the selected head. Thermal Compensation is per-
 formed during startup and every 2 minutes thereafter. This periodic
 compensation coincides with a host command service operation. The
 last command execution time will increase by 100 msec. typical or
 125 msec. maximum.


 Read/Write Head Auto-Park
 -------------------------
 Upon power-down, the read/write heads automatically move to the
 shipping zone. All portions of the head/slider assembly park inboard
 of the maximum data cylinder. When power is applied, the heads re-
 calibrate to Track 0.


 Start/Stop Time
 ---------------
 After DC power has been applied, the drive becomes ready within 20
 seconds unless the Motor Start option is disabled. During this time,
 the drive responds to the SCSi interface. Stop time is about 10
 seconds if the drive was commanded to stop and DC power was not
 removed. Otherwise, no dynamic braking is applied, so stop time is
 considerably longer than 10 seconds.

 If the Motor Start option is enabled the internal controller accepts
 a Motor Start, Inquiry, or Request Sense command via the SCSI inter-
 face 3 seconds after DC power has been applied. After the Motor Start
 command has been received, the drive becomes ready for read/write
 operations within 20 seconds. During this time, the drive responds to
 the SCSI interface.

 Note: Do not move the drive until the motor has come to a complete
       stop.

 There is no power control switch on the drive.



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SEAGATE   SCSI CONNECTOR

 Evolution of the SCSI Connector:
 The Single Connector Standard
 -----------------------------

 Introduction
 ------------
 The advent of SCSI as the interface of choice among high-performance
 system designers has provided several benefits for the computing
 industry. Unlike traditional interface designs which usually only
 allow two data storage peripherals, SCSI allows the use of multiple
 peripherals operating on a common bus. Because of the expandability,
 power and flexibility afforded by this implementation, system
 designers quickly embraced SCSI as the optimal interface for
 performance intensive computing platforms.

 Unfortunately, the very elements which provide this flexibility and
 expandability also created difficulty in the configuration and
 installation of several peripherals within a single enclosure.
 Furthermore, the increasing popularity of disc arrays and
 mass-storage subsystems has created the need for efficient and
 simplified component designs.

 Currently, installing a SCSI drive is a complex procedure. Apart from
 physically mounting the drive within the system chassis, there are
 the additional tasks of attaching the interface and power cables to
 their appropriate connectors, and placing several jumpers on the
 circuit board to configure the drive for proper operation within the
 SCSI subsystem.

 These jumpers are used to designate mandatory options such as a
 specific SCSI ID for that drive, and application specific
 options such as a delayed or remote start of the spindle motor. If a
 visual indication of drive operation is desired, an additional cable
 attachment is necessary for the activity LED. For applications which
 require several drives to synchronize their spindle rotation, yet
 another connection must be made to provide the drive with an external
 clock signal.

 To complicate matters, the SCSI interface itself is specifically
 designed to accommodate the concurrent operation of several
 peripherals simultaneously. Under such circumstances, the task of
 configuring, installing and connecting several peripherals multiplies
 the number of necessary operations. Maintenance of such an
 arrangement can become very complicated -- the proverbial "Plumber's
 nightmare."

 The Single Connector Standard as proposed by Sun Microsystems,
 Seagate Technology and other drive manufacturers is an ideal design
 solution for these problems. The Single Connector was created to
 facilitate the expandability and flexibility of the SCSI interface,
 while simplifying the  intricacies of peripheral installation and
 interconnection. In addition to vastly simplifying this process, the
 standard also encompasses all of the critical elements necessary for
 migration to the Fast and Wide implementations of SCSI.


 Evolution of the Connector
 --------------------------
 In short, the Single Connector is true to its name. It integrates the
 power connector, the interface connector, the SCSI ID jumpers, the
 LED signal, and several other functions into a single unit. The
 intent of the design is to create a single point of contact for all
 electrical and electronic connection necessary to operate a SCSI
 peripheral. As such, it represents an evolution from earlier,
 disjoint methods to a single, unified system of peripheral
 attachment.

 Present within the connector is the full complement of interface
 signals required for the 8-bit bandwidth of the standard SCSI
 interface. Also present, are the additional signal lines required for
 Fast/Wide SCSI, which support 16-bit operation as well. The Fast/Wide
 SCSI specification also extends the maximum number for peripherals
 common to a SCSI bus from eight units to 16 units. The Single
 Connector Standard provides support for all requirements for the
 operation of Fast/Wide SCSI. Therefore, the migration to Fast/Wide
 SCSI from standard SCSI is already built into the specification.

 In addition to the interface signals, the standard also includes the
 provision of setting a device's SCSI ID via system software. Four
 signal lines have been designated to allow the host system to assign
 a device's SCSI ID. This includes option of dynamically reassigning
 and software device selection. For applications which require
 on-the-fly adjustment of the peripheral ID and selection status on
 the SCSI bus, this feature is invaluable.

 Special features required by specific types of applications have also
 been integrated in to the Single Connector specification. First, the
 inclusion of a specific Spindle Synchronization signal will provide
 an essential feature to the design of many disc array and RAID array
 systems. The synchronization process begins with a clock pulse
 generated by an external source, such as the host, or perhaps another
 drive. An individual drive is able to coordinate the rotation of its
 spindle motor to the clock signal, which insures all drives within
 that subsystem are rotating in concert. Many disc arrays require this
 feature for coherent operation of multiple components as a unified
 whole.

 Other special features supported by the connector are Delayed Spindle
 Start and Remote Spindle Start.
 Delayed motor start is usually necessary for systems which need time
 to initialize the host system before the drives are needed on-line.
 Certain systems have special power consumption requirements which
 also require the Delayed Spindle.

 Start option. The Remote Spindle
 Start option is a feature which allows the host to control when the
 drive initiates spin-up of the spindle motor. In large disc arrays
 some drives are assigned special functions (such as data backup), and
 consequently are used rarely. In such cases there is no need for the
 drive to be spinning, as long as the electronic circuitry on the
 drive is active. Remote Spindle Start allows the drive's electronics
 to remain active, while the spindle is at rest. When data is
 necessary from the drive, the command is sent to start the spindle
 motor. This feature conserves system power and minimizes wear on the
 spindle motor.

 The last elements integrated into the Single Connector are the power
 lines. The specification provides both +5 Volt and +12 Volt power,
 with dedicated ground for each. Specifically, there are four +12 Volt
 and 12 Volt ground lines, with three +5 Volt and 5 Volt ground lines.
 The power and ground lines are strategically positioned on the
 connector to mitigate the effects of electro-magnetic interference
 with the signal lines.

 Finally, the connector was originally designed to fit onto the
 chassis of low profile (1-inch height) 3.5" disc drive.
 However, the connector itself can fit 1.6-inch high 3.5-inch disc
 drives and 2.5-inch drives as well. This flexibility provides
 for the migration to smaller form-factor drives as well.


 Advantages
 ----------
 The structure of the connector connotes modifications to the host
 chassis. The impetus for the development of the Single Connector was
 the need for simplification of the host design. The chief objectives
 included the reduction of complexity in attaching or replacing a
 peripheral. Essential to the simplification process is the
 implementation of a series of mating connectors mounted on the host
 system backplane. Properly designed backplanes would allow the
 installation of a drive without the need for attaching any cables. In
 fact, backplane mounting provides an immediate solution for two
 common problems associated with traditional installment. First, the
 Single Connector backplane avoids the tangle of interface cables,
 power cables, LED activity indicators and so forth. Fears of
 malfunctioning wires and twisted cables are also allayed. One
 connection provides for all of the functions and helps alleviate all
 of the problems.

 More importantly, electro-magnetic noise which is incurred from
 adjacent cables is completely eliminated, since there are no cables
 necessary in the interface connection. This helps preserve the
 integrity of the data on the SCSI bus and prevents signal corruption.

 Probably the best feature of the of Single Connector implementation
 is the capability it provides for blind mating the drive to the host.
 Since all necessary functions are integrated within the connector, a
 single action is all that is necessary to install a drive. Blind
 mating greatly simplifies peripheral attachment in critical
 applications such as network data servers, RAID arrays and data
 backup systems. With proper design of the backplane and mounting
 frame, a technician will be able to install a drive by simply sliding
 the drive along the mounting rails until it mates with the
 connector. The installation would be done without the need for
 reaching in to the mounting enclosure, without setting any
 configuration jumpers, or attaching any cables. Even the drive
 configuration can be done by the host via the ability to softselect
 the drive's SCSI ID and operating parameters. Blind plane mating
 gives the Single Connector unparalleled ease and time savings for
 peripheral installation.


 Summary
 -------
 The manifold advantages of Single Connector are largely self-evident.
 The spindle synchronization and ease of mounting create an excellent
 solution for RAID implementations. The capability to remotely
 configure the drive and ease of installation naturally lends the
 Single Connector for use in networked environments.

 Furthermore, the ability to migrate to other platforms is a key
 factor in the viability and growth potential of the Single Connector
 Standard. Therefore, the single Connector is an excellent choice for
 system designers wishing to simplify the host design process through
 streamlining and integration. The ability to migrate upward to
 Fast/Wide SCSI, or down-size to the 2.5-inch form-factor,
 concurrently allows the system to accommodate higher bus bandwidths
 and upcoming peripheral form-factors.

 The Single Connector provides unprecedented ease, speed and
 integrated upgradability within a single specification. It has a high
 potential for simplifying a vast number of applications while
 simultaneously reducing installation time and costs. The Single
 Connector signifies an evolution of the SCSI connector. It provides
 the rarest of combinations:

 enhanced simplicity, reduced cost, and an increased time savings.


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