
1 9 2 6   S    MICROPOLIS
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/FH              Cylinders    2759|     |     |
Capacity form/unform  2158/ 2550 MB        Heads          15|     |     |
Seek time   / track  13.0/ 2.0 ms          Sector/track     |     |     |
Controller           SCSI2 SI/FAST         Precompensation
Cache/Buffer           512 KB SEGMENTED    Landing Zone
Data transfer rate    4.500 MB/S int       Bytes/Sector      512
                     10.000 MB/S ext SYNC
Recording method     RLL 1/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 50    |    -40 65
Power: sleep              W     Humidity     %        10 90    |     10 90
       standby       29.5 W     Altitude    km    -0.061  3.048| -0.305 15.240
       idle               W     Shock        g         8       |     30
       seek          31.0 W     Rotation   RPM      5400
       read/write         W     Acoustic   dBA        40
       spin-up            W     ECC        Bit   64
                                MTBF         h     250000
                                Warranty Month
Lift/Lock/Park     YES          Certificates


**********************************************************************
                        L   A   Y   O   U   T
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MICROPL. 1926  PRODUCT DESCRIPTION 110872 REV. A

  +---------------------------------------------------------+
  |                                                         |XX
  |  Component Side                                         |XX J2
  |  No. 150072 Rev. A4                                     |XX
  |                                                         |1X
  |                                                         |
  |                                 Slave SyncxxW3      RN4+|XX
  |                                Master SyncxxW4        |||XX
  |                                                       |||XX
  |                                                       ++|XX
  |                                                         |XX J1
  |                                                     RN5+|XX
  |                                                xxW5   |||XX
  |                                              W6xxxW8  |||XX
  |                                                       ++|XX
  |  +-+J11                                                 |  1
  |  +-+LED Connector             Frame Ground++W7          |XX J3
  |                                           ++            |XX
  +---------------------------------------------------------+  1






     +--------------------------------------+
     |         ++J4                         |
     |         ++                           |
     |    ++J5                              |
     |    ++                                |
     |                                      |
     |   J2             J1            J3    |
     +..........-XXXXXXXXXXXXXXXXXX-XXXXXXXX+
     +-Multi---1---Signal---------1--------1+
                                     Power



**********************************************************************
                      J   U   M   P   E   R   S
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MICROPL. 1926  PRODUCT DESCRIPTION 110872 REV. A

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

 x = Factory default


 J2  Multi-Function Connector
 ----------------------------


 SCSI-1/SCSI-2 Option--------+     +---------Spindle Control Option
                             |     |  +------ID2
   Bus Parity Check Option+  |     |  |  +---ID1
           Remote LED--+  |  |     |  |  |   ID0
          +--+--+--+--++-++-++-+--++-++-++-+-++ +-----
          |23|21|19|17|15|13|11|09|07|05|03|01+-+
          |24|22|20|18|16|14|12|10|08|06|04|02+-+  J1
          ++-+--++-+--++-+--+--+--+--+--+--+--+ +------
 Remote LED+     |     |
 +5V             |     |
         Slave Sync    Master
                       Sync

 Note: Pins 2, 4, 6, 8, 10, 12, and 14 are tied to Ground.

 Pins: 09, 10, 17, 18, 19, 21, 22, 23 are RESERVED.


 Multi-Function Connector J2 Pin Assignments
 -------------------------------------------
 +---+---------------+---+--------------+
 |Pin| Signal Name   |Pin|Signal Name   |
 +---+---------------+---+--------------+
 | 1 |ID0            | 2 |GROUND        |
 +---+---------------+---+--------------+
 | 3 |ID1            | 4 |GROUND        |
 +---+---------------+---+--------------+
 | 5 |ID2            | 6 |GROUND        |
 +---+---------------+---+--------------+
 | 7 |Spindle Control| 8 |GROUND        |
 +---+---------------+---+--------------+
 | 9 |RESERVED       |10 |GROUND        |
 +---+---------------+---+--------------+
 |11 |SCSI-1/SCSI-2  |12 |GROUND        |
 +---+---------------+---+--------------+
 |13 |BUS Parity     |14 |GROUND        |
 +---+---------------+---+--------------+
 |15 |Remote LED     |16 |MASTER SYNC   |
 +---+---------------+---+--------------+
 |17 |RESERVED       |18 |Not Connected |
 +---+---------------+---+--------------+
 |19 |RESERVED       |20 |Slave Sync    |
 +---+---------------+---+--------------+
 |21 |RESERVED       |22 |RESERVED      |
 +---+---------------+---+--------------+
 |23 |RESERVED       |24 |Remote LED +5V|
 +---+---------------+---+--------------+


 J2  SCSI ID
 -----------
 Up to eigth devices (the host and seven targets) can be attached to
 the SCSI bus. The 1926 drive has three ID jumpers - ID0, ID1, and
 ID2. In multiple-device systems, each drive must have its own unique
 ID. The three jumpers are used to assign one of the eight SCSI ID
 bits (0 through 7) to the drive.

   +----------+-----------------------+
   | SCSI ID  |        Jumpers        |
   |          | ID2   | ID1   | ID0   |
   +----------+-------+-------+-------+
   |    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  |
   | x  7     | CLOSED| CLOSED| CLOSED|
   +----------+-------+-------+-------+


 Interface Terminator packs RN4 and RN5 provide proper termination
 for the interface lines. For a multiple-drive system, the terminator
 packs are installed in the last drive on the cable.


 J2  Spindle Control Option
 --------------------------
     Pin 7-8 CLOSED  The drive must wait for an interface START UNIT
                     command to start the spindle motor.
             OPEN    The drive automatically starts the spindle motor
                     at power-on. (Factory default configuration)


 J2  SCSI-1/SCSI-2 Option
 ------------------------
   x Pin 11-12 CLOSED The drive is in SCSI-2 mode.
               OPEN   The drive is in SCSI-1 mode.

 This jumper works in conjunction with the Change Definition SCSI
 Command. When the jumper is omitted, the resultant SCSI mode will be
 the reserve of what the Change Definition Command had set.


 J2  Bus Parity Check Option
 ---------------------------
     Pin 13-14 CLOSED  The drive neither generates nor detects parity.
   x           OPEN    The drive generates parity and enables parity
                       detection.


 J2  Remote LED Option
 ---------------------
 A remote LED installed between pins 15 (base of LED) and 24 (Remote
 LED +5V) of J2 will provide the remote LED operation.


 J4/J5  Ground Connectors
 ------------------------
 3/16-inch spade lugs J4 and J5 are provided for grounding.
 System characteristics determine proper ground connection.


 W3/4  Spindle Synchronization Option
 ------------------------------------
 Jumpers installed (CLOSED) at W3 and W4 provide termination for the
 Spindle Synchronization signals (Slave Sync and Master Sync respect-
 ively).


 The Rotational Position Locking field (MODE SELECT command, Page Code
 04h) is used to specify spindle synchronization operation.

 Unsynchronized: If the drive is set to Unsynchronized (RPL = 00b), it
 ignores the SLAVE SYNC signal.

 Slave: If the drive is set to Slave (RPL = 01b), it does not generate
 the MASTER SYNC signal or the SLAVE SYNC signal but synchronizes its
 index to the SLAVE SYNC signal (J2, pin 20) supplied by an external
 source.

 Signal termination is placed on the SLAVE SYNC signal at the first
 and last drive in the chain only.

 Master: If the drive is set to Master (RPL = 10b), it generates the
 SLAVE SYNC output signal (J2, pin 20) for use directly by the slave
 drives.

 Signal termination is placed on the SLAVE SYNC signal at the first
 and last drive in the chain only.

 Master Control: If the drive is set to Master Control (RPL = 11b), it
 generates the MASTER SYNC signal (J2, pin 16). This output is used by
 the controller to generate the SLAVE SYNC signal (J2, pin 20) for the
 slaves.

 Signal termination is placed on the MASTER SYNC signal at the first
 and last drive in the chain only.

 Signal termination is placed on the SLAVE SYNC signal at the first
 and last drive in the chain only.


 W5/W6/W8  Bus Termination Power Option
 --------------------------------------

   +-----------------------+------------------------------------+
   |        Jumpers        |                                    |
   |  W6   |  W8   |  W5   |                                    |
   +-------+-------+-------+------------------------------------+
   | CLOSED| OPEN  | OPEN  |The drive provides terminator power |
   |       |       |       |to its on-board terminators         |
   |       |       |       |(Factory default configuration)     |
   +-------+-------+-------+------------------------------------+
   | OPEN  | CLOSED| OPEN  |On-board term. PWR is provided by   |
   |       |       |       |host via interface cable J1, pin 26 |
   +-------+-------+-------+------------------------------------+
   | CLOSED| OPEN  | CLOSED|The drive provides terminator power |
   |       |       |       |to its on-board terminators and     |
   |       |       |       |also to the SCSI bus via interface  |
   |       |       |       |cable J1, pin 26 (TERMPWR)          |
   +-------+-------+-------+------------------------------------+

 A jumper is installed at W6, at W8, or at W6 and W5 to select the
 source of terminator power (+5V) for the SCSI bus terminator packs on
 the Device Electronics board.


 W7  Frame Ground Option
 -----------------------
      W7  CLOSED  Frame ground is connected to logic ground
          OPEN    Frame ground is not connected to logic ground
                  (Factory default configuration)


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



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                      I   N   S   T   A   L   L
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MICROPL. 1926  PRODUCT DESCRIPTION 110872 REV. A

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

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

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


 Dimensions and Mounting
 -----------------------
 The 1926 drive uses industry-standard mounting techniques for 5 -inch
 full-height Winchester disk drives.

 The drive is designed such that the outer frame should be hard-
 mounted to the host equipment; no additional/external shock mounts
 should be used.

 Recommended orientation is vertical on either side, or horizontal
 with the Device Electronics board down; other mounting orientations
 may be used.

 No matter what mounting orientation is used, Micropolis specifies
 that the maximum HDA casting temperature not exceed 60*C (140*F).


 Mounting Screws
 ---------------
 2 per side 6-32 UNC-2B
 4 on bottom 6-32 UNC-2B

 Caution: The mounting screws must be selected so that they do not
 penetrate the bottom mounting holes by more than 0.20 inches or the
 side mounting holes by more than 0.156 inches.

 Screws that are too long will short to PCBA components and/or prevent
 operation of the shock mount system.


 SINGLE-ENDED Interface Electrical Characteristics
 -------------------------------------------------
 Interface control and status signals are digital (open collector TTL)
 using industry-standard transmitters and receivers which provide
 a terminated, single-ended system.

 The assigned signals are terminated with 220 ohms to +2.85V
 (nominal). All signals use open-collector or three-state drivers.

 Single-ended drivers and receivers allow a maximum cable length of
 six meters (primarily for connection within a cabinet).

 Signal transmission requires a single 50-conductor cable. A
 characteristic impedance of 100 ( 10%) ohms is recommended for un-
 shielded flat or twisted pair ribbon cable.

   a. Input Characteristics

      Each of the drive's signal receivers has the following
      characteristics when measured at the interface connector.

      1)  Signal true = 0.0 VDC to 0.8 VDC

      2)  Maximum total input load = -0.4 milliamps at 0.5 VDC

      3)  Signal false = 2.0 VDC to 5.25 VDC

      4)  Minimum input hysteresis = 0.2 VDC


   b. Output Characteristics

      Each driven signal has the following characteristics when
      measured at the interface connector.

      1)  Signal assertion = 0.0 VDC to 0.5 VDC

      2)  Minimum driver output capability = 48 milliamps (sinking) at
                                             0.5 VDC.

      3)  Signal negation = 2.5 VDC to 5.25 VDC


   c. Terminator Power (TERMPWR at Pin 26)

      Terminator Power has the following requirements:

      V(TERM) = 4.25 VDC to 5.25 VDC

      900 milliamps minimum source drive capability, with 1.0 amp
      recommended current limiting (e.g., a fuse).

      1.0-milliamp maximum bus loading (except for the purposes of
      providing power to an internal terminator).

 Keyed connectors are provided to prevent accidental grounding or
 misconnection of terminator power.

 Interface Terminator packs provides proper termination for the
 single-ended interface lines. For a multiple-drive system, the
 terminator pack is installed in the last drive on the cable.


 Signal Connector J1
 -------------------
 J1 is a 50-pin connector. The signals on J1 include the 8-bit SCSI
 bus and various control and handshaking lines.

 Recommended Cable: 3M Scotchflex 3365/50 or equivalent.
 Mating connector:  3M P/N 3425-3000 or equivalent.


 J2 Multi-Function Connector/Jumper Block
 ----------------------------------------
 J2 is a 24-pin, multi-function connector/jumper block. This
 connector is used for device addressing and various other options.


 J3  DC Power Connector
 ----------------------
 J3 is a 4-pin, keyed, AMP MATE-N-LOCK connector. Both +5V and +12V
 are supplied to the drive via this connector.

    Mating Connector:   AMP 1-480424-0 or equivalent
                Pins:   AMP 350078-4
 Suggested Wire Size:   18 AWG


 Ground Connectors J4 and J5
 ---------------------------
 3/16-inch spade lugs J4 and J5 are provided for grounding. Systems
 characteristics determine proper ground connection.

 Mating connector: AMP 60972-2 or equivalent.


 LED Connector J11
 -----------------
 Recommended mating Connector: Dupont 69305-002 or equivalent
 Pins: Dupont 77138-001
 Suggeszed Wire Size: 26-30 AWG


 Multiple-Drive Systems
 ----------------------
 Up to seven 1926 drives can be connected to a single host.

                                             Drive #1
  +------HOST------+                 +-----------------+
  | +-----------+  +--+-SCSI-BUS-----+ J1              |
  | |Terminators|  |  |       +------+ J3   J4/J5      |
  | +-----------+  |  |       |      +--------+--------+
  |                |  |       |               +------------------+
  +----------------+  |       |              Drive #2            |
                      |       |      +-----------------+         |
                      +-------+------+ J1              |         |
                      |       o------+ J3   J4/J5      |         |
                      |       |      +--------+--------+         |
                      |       |               +------------------+
                      |       |              Drive #3            |
                      |       |      +-----------------+         |
                      +-------+------+ J1              |         |
                      |       o------+ J3   J4/J5      |         |
                      |       |      +--------+--------+         |
                      |       |               +------------------+
                      |       |              Drive #4            |
                      |       |      +--------------+--+         |
                      +-------+------+ J1           |T |         |
                              o------+ J3   J4/J5   +--+         |
           --DC-Voltages------+      +--------+--------+         |
           ---GROUND--------------------------+------------------+

 T = TERMINATORS

 Terminators are installed ONLY in the last physical drive in the
 control chain.

 Connectors J4 and J5 are provided for grounding; system character-
 istics determine the proper ground connection.


 Adjustments and Maintenance
 ---------------------------
 1926 drives requires no adjustments or periodic maintenance;
 additionally, no mechanical adjustments are required to prepare a
 system for handling or shipment.


 Field-Replacable Components
 ---------------------------
 The concept of repair by replacement of complete functional
 components is utilized in the 1926, resulting in an MTTR of less
 than 15 minutes.



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                      F   E   A   T   U   R   E  S
**********************************************************************
MICROPL. 1926  PRODUCT DESCRIPTION 110872 REV. A

 Description
 -----------
 This Product Description describes the Micropolis 1926 single-ended
 high-performance, 5 -inch full-height Rigid Disk Drive. The 1926 is a
 reduced capacity version of the popular field-proven 1936 family of
 drives.

 The 1926 disk drives provide random-access, high-speed, data storage
 and meet the needs of diverse applications environment. The drives
 are compatible with the "ANSI CCS/SCSI-1" and "SCSI-2" versions of
 the industry-standard Small Computer System Interface (SCSI)
 specification.


 Some Features of the 1926 Drives
 --------------------------------

 - The drive supports fully-programmable automatic retries, including
   the use of ECC. These features, together with defect mapping and
   automatic reallocation, afford the system a high degree of
   protection against the effects of hard errors.

 - Rugged dual-chassis construction suspends the HDA on shock/vibra-
   tion isolators to provide exceptional protection during shipment,
   system installation, and operation.

 - Positive media protection is achieved during spin down (due to a
   STOP UNIT command or power off) by automatically retracting and
   locking the positioner in a data-free landing zone.

 - Center Servo - with the servo head placed in the middle of the disk
   stack, the highest possible positioner accuracy is provided within
   a broad range of environments.

 - A sophisticated multi-segment read-ahead algorithm dramatically
   improves response time for many read operations.

 - Supports the disconnect/arbitrate/reconnect operation.

 - Loadable code provides for SCSI Firmware upgrades via the SCSI
   interface.

   The drive can electronically download SCSI Firmware via the SCSI
   interface. This eliminates the need to remove/install the EPROM IC,
   which reduces labor time and eliminates the risk of damage to the
   drive.

 - Performance is enhanced by low SCSI command overhead. Intelligent
   features such as read-ahead and sophisticated buffer management
   make maximum use of the 512K data buffer, with up to eight
   segments, which has full parity for data integrity.


 Media Defects
 -------------
 Media defects are physical characteristics of the media which result
 in repetitive read errors when a functional drive is operated within
 specified operating conditions.

 At the time of manufacture, a media test system evaluates every
 drive and identifies each media defect location. The defective
 areas are identified by head address (HD), cylinder address (CYL),
 and number of bytes from Index (BFI).

 The list of manufacturer-found defects is stored on the drive in a
 reserved, write-protected area accessible by the SCSI controller.
 This list is known as the MDL (Manufacturers Defect List) or PList
 (Primary Defect List).

 A printed listing of the defects is also shipped with each drive. The
 entries it contains can be mapped out (reassigned) automatically at
 format control parameter bits.


 Seek Time
 ---------

                                          | 1926   |
        ----------------------------------+--------+
        Track-to-Track  read   msec. typ. |   1.4  |
                        write  msec. typ. |   2.4  |
                       Average msec. typ. |  13    |
                               msec. max. |  26.5  |
        ----------------------------------+--------+


 Recording Media
 ---------------
 The aluminium disks, each 130 millimeters (5 1/4 inches) in diameter,
 are mounted on the spindle assembly. The recording surface on each
 disk is a thin coating of magnetic material.


 Air Filtration System
 ---------------------
 The 1926 drives are designed to provide contamination control within
 the sealed HDA throughout the life of the drive with zero
 maintenance.

 Air within the HDA is continuously recirculated and filtered through
 a high efficiency filter. Air is ducted to and from the filter for
 maximum pressure recovery and filter efficiency. Air within the HDA
 may only enter the drive through a high-efficiency breather filter.


 Breaking
 --------
 The heads contact a start/stop (landing zone) area of the disk
 surface which is not used for data storage when the disks are not
 spinning and during start and stop cycles. Dynamic braking is used to
 stop the spindle quickly.


