
1 9 0 8 - 1 5    MICROPOLIS
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/FH              Cylinders    2100|     |     |
Capacity form/unform  1381/ 1600 MB        Heads          15|     |     |
Seek time   / track  10.0/ 2.0 ms          Sector/track     |     |     |
Controller           SCSI2 SINGLE-ENDED    Precompensation
Cache/Buffer           256 KB READ-AHEAD   Landing Zone
Data transfer rate    5.000 MB/S int       Bytes/Sector      512
                     10.000 MB/S ext SYNC
Recording method     RLL                            operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 50    |    -40 65
Power: sleep              W     Humidity     %        10 90    |     10 90
       standby       25.0 W     Altitude    km    -0.061  3.048| -0.305 15.240
       idle               W     Shock        g         3       |     40
       seek          30.0 W     Rotation   RPM      5400
       read/write         W     Acoustic   dBA        40
       spin-up            W     ECC        Bit   64
                                MTBF         h     150000
                                Warranty Month        60
Lift/Lock/Park     YES          Certificates


**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
MICROPL. 1908S/D  PRODUCT DESCRIPTION 105707 REV. A

   Single-Ended
  +---------------------------------------------------------++-+
  |                                                         ||X20
  |   COMPONENT SIDE                                        ||X|
  |                                                         ||X|J2
  |                                                         ||X|
  ++                                                        |1-2
  ||                                                  ++W12 |XX
  ||                                                  ++    |XX
  ||                                                +-+     |XX
  ||                                                | |RN6  |XX J1
  ||                                                | |     |XX
  ||                                                | |     |XX
  ||                                                +-+     |XX
  ++                                               W2--W1   |XX
  |                                                +---+    |XX
  |                                                         |  1
  |                                          ++W11          |XX J3
  |                                      ++++++             |XX Power
  +--------------------------------------+--+---------------+  1





    Differential
  +---------------------------------------------------------++-+
  |                                                         ||X20
  |   COMPONENT SIDE                                        ||X|
  |                                                 +-RN12  ||X|J2
  |                                                 | |     ||X|
  ++                                                | |     |1-2
  ||                                                +-+     |XX
  ||                                               W2--W1   |XX
  ||                                               +---+    |XX J1
  ||                                               +-W10    |XX
  ||                                               +-+      |XX
  ||                                                +-RN11  |XX
  ||                                                | |     |XX
  ++                                                | |     |XX
  |                                                 +-+     |XX
  |                                                         |  1
  |                                          ++W11          |XX J3
  |                                      ++++++             |XX Power
  +--------------------------------------+--+---------------+  1






     +---------------------------------------+
     |          ++J4 HDA Ground Connector    |
     |          ++                           |
     |     ++J5 Frame Ground Connector       |
     |     ++                                |
     |                                       |
     |    J2    1        J1        1   J3   1|
     +...........-XXXXXXXXXXXXXXXXXX-XXXXXXXX+
     +-+-+++-++++---Signal------------Power--+
       | ||| ||||
       | ||| |||+--- SCSI ID0 Pins 1 & 2
       | ||| ||+---- SCSI ID1 Pins 3 & 4
       | ||| |+----- SCSI ID2 Pins 5 & 6
       | ||| +------ Spindle Control Option Pins 7 & 8
       | ||+-------- Write Protect Option Pins 11 & 12
       | |+--------- Bus Parity Check Option Pins 13 & 14
       | +---------- Master Sync Pin 16
       +------------ Slave Sync Pin 20



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
MICROPL. 1908S/D  PRODUCT DESCRIPTION 105707 REV. A

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

 x = Factory default configuration


 Differential Board
 ------------------
 While the option jumpers may be positioned at locations different
 from the single-ended version of the Device Electronic board, the
 options supported are the same.


 Interface Terminator
 --------------------
 Interface Terminator pack RN6 (RN11/RN12) provides proper termination
 for the interface lines. For a multiple-drive system, the terminator
 pack is installed in the last drive on the cable.


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


    Write Protect Option-----+     +---------Spindle Control Option
                             |     |  +------ID2
 Bus Parity Check Option--+  |     |  |  +---ID1
                          |  |     |  |  |   ID0
          +--+--+--+--+--++-++-+--++-++-++-+-++ +---
          |  |  |20|  |16|14|12|  |08|06|04|02+-+ J1
          |  |  |  |  |  |13|11|  |07|05|03|01+-+
          +--+--++-+--++-+--+--+--+--+--+--+--+ +--
      Slave Sync-+     Master
                       Sync



 J2  SCSI ID
 -----------
   +----------+-----------------------+
   | SCSI ID  |        Jumpers        |
   |          | ID2   | ID1   | ID0   |
   +----------+-------+-------+-------+
   |x   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|
   +----------+-------+-------+-------+

 Up to eight devices (the host and seven targets) can be attached to
 the SCSI bus. The 1908 drive has three ID jumpers. These three
 jumpers are used to assign one of the eigth SCSI ID bits (0 through
 7) to the drive.

 In multiple-device systems, each drive must have its own unique ID
 bit.


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


 J2  Write Protect Option
 ------------------------
     Pin 11-12 CLOSED  The drive is write protected.
                          CAUTION: The drive can still be formatted.
             x OPEN    The drive is not write protected. (Factory
                       default configuration)



 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.



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


 W1/W2/W12  Bus Termination Power Option
 ---------------------------------------

   +-----------------------+------------------------------------+
   |        Jumpers        |                                    |
   |  W1   |  W2   |  W12  |                                    |
   +-------+-------+-------+------------------------------------+
   | CLOSED| OPEN  | OPEN  |The drive provides terminator power |
   |       |       |       |to its on-board terminators         |
   |       |       |       |(Factory default configuration)     |
   +-------+-------+-------+------------------------------------+
   | OPEN  | CLOSED| OPEN  |Terminator power is provided by the |
   |       |       |       |host via interface cable J1, pin 26 |
   +-------+-------+-------+------------------------------------+
   | OPEN  | CLOSED| 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 W1, at W2, or at W2 and W12 to select the
 source of terminator power (+5V) for the SCSI bus terminator packs on
 the Device Electronics board.

 Do not install jumpers at both W1 and W12.


 Spindle Synchronization Option
 -------------------------------
 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.

 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.

 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.


 W11  Frame Ground Option
 ------------------------
      W11  CLOSED  Frame ground is connected to logic ground
         x OPEN    Frame ground is not connected to logic ground



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



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
MICROPL. 1908S/D  PRODUCT DESCRIPTION 105707 REV. A

 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


 Dimensions and Mounting
 -----------------------
 The 1908 drive uses industry-standard mounting techniques for 5 -inch
 full-height Winchester disk drives.

 Recommended orientation is vertical on either side, or horizontal
 with the Device Electronics board down; other mounting orientations
 may be used provided the ambient air temperature around the drive is
 kept at or below 50*C (122*F).

 The term "ambient" becomes imprecise when referencing a drive in a
 system, since it is difficult to determine where the air temperature
 should be measured. To help resolve this confusion, Micropolis
 specifies that the maximum HDA casting temperature (regardless of the
 air temperature around the drive) is 60*C (140*F). Not exceeding this
 temperature will ensure that the head-to-media interface never exceed
 its temperature limit.


 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 +5V (nominal)
 and 330 ohms to ground at each end of the cable. 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

      800 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).

 The 1908 disk drive provides keyed connectors to prevent accidental
 grounding or misconnection or terminator power.


 Interface Terminator pack RN6 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.


 DIFFERENTIAL Interface Electrical Characteristics
 -------------------------------------------------
 Differential interface signals consist of two signal lines which are
 denoted +SIGNAL and -SIGNAL.

 A signal is defined as true when the +SIGNAL is more positive than
 the -SIGNAL.
 A signal is defined as false when the -SIGNAL is more positive than
 the +SIGNAL.

 Differential drivers and receivers allow a maximum cable length of
 25 meters.

 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 minimum conductor size of 28 AWG should be employed to minimize
 noise effects and ensure proper distribution of optional terminator
 power.

 A stub length of no more than 0.2 meters is allowed off the main-line
 interconnection within any connected equipment.

   a. Input Characteristics

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

      I (input current on either input) =   2.0 milliamps, maximum

      Note: These characteristics include both receivers and passive
      drivers.


      This requirement is met with the input voltage varying between
      -7V and +12V, with power either on or off, and with hysteresis
       equaling 35 millivolts, minimum.

   b. Output Characteristics

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

      VOL (low-level output voltage) = 1.7V maximum at IOL
           where IOL = 55 milliamps

      VOH (high-level output voltage) = 2.7V maximum at IOH
          where IOH = -55 milliamps

      VOD (differential voltage) = 1.0V minimum, with common-mode
          voltage ranges from -7 to +12

      VOL and VOH are measured between the output terminal and the
      SCSI device's logic ground reference.


   c. Terminator Power (TERMPWR at Pins 25 and 26)

      Terminator Power has the following requirements:

      V(TERM) = 4.0 VDC to 5.25 VDC

      600 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).

 The 1908D drive provides keyed connectors to prevent accidental
 grounding or misconnection of terminator power.

 Interface Terminator packs RN11 and RN12 provide proper termination
 for the differential interface lines.


 Signal Connector J1
 -------------------
 J1 is a 50-pin connector. Signal interface connection is made via
 this 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.


 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.


 Multiple-Drive Systems
 ----------------------
 Up to seven 1908 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
 ---------------------------
 1908 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 1908, resulting in an MTTR of less
 than 15 minutes.



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
MICROPL. 1908S/D  PRODUCT DESCRIPTION 105707 REV. A


 Micropolis 1908S (single-ended) and 1908D (differential) high-
 performance, 5 -inch full-height Rigid Disk Drives provide OEMs with
 random-access, high-speed data storage and meet the needs of diverse
 applications environment. These drivers are compatible with the
 "ANSI CCS" and "SCSI-2" versions of the industry-standard Small
 Computer System Interface (SCSI) specification.


 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). A printed listing of the
 defects is also  shipped with each drive.

 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).

 The entries it contains can be mapped out (reassigned) automatically
 during the operation by appropriate use of the format control para-
 meter bits.


 Seek Time
 ---------

                                          | 1908   |
        ----------------------------------+--------+
        Track-to-Track  read   msec. typ. |   2    |
                        write  msec. typ. |   3    |
                       Average msec. typ. |  11,5  |
                               msec. max. |  25    |
        One-Third Stroke       msec. max. |  12.5  |
        Latency                msec. avg. |   5.56 |
        ----------------------------------+--------+


 Air Filtration System
 ---------------------
 The 1908 drives are designed to provide contamination control within
 the sealed HDA throughout the life of the drive with zero
 maintainance.

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


 Data Transfers
 --------------
 1908 drives are capable of transferring data up to 10 MBytes/sec in
 synchronous mode and 4 MBytes/sec in asynchronous mode. In some
 configurations (e.g., short cable and fast host), faster asynchronous
 transfer rates can be achieved.

 Internal Transfer Rate 30 to 40 MHz.


 Multi-Segment Read-Ahead
 ------------------------
 The Multi-Segment Read-Ahead function partitions the data buffer
 into multiple small buffers or segments. The read-ahead function
 causes the 1908 drive to transfer the requested block into its buffer
 and continue to read sequential blocks until the buffer (or segment)
 is filled or another command is received.

 On subsequented request for data, the buffer will be checked for the
 requested blocks. If the data already resides in the buffer, it will
 be transferred to the host and no media access will be necessary.
 This results in a significant improvement in performance.


