
H M D - 7 2 6 A    EPSON
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders     615|     |     |
Capacity form/unform    20/      MB        Heads           4|     |     |
Seek time   / track  80.0/18.0 ms          Sector/track   33|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer               KB              Landing Zone
Data transfer rate    0.625 MB/S int       Bytes/Sector      256
                            MB/S ext
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         5 50    |    -40 65
Power: sleep              W     Humidity     %         8 80    |      8 85
       standby            W     Altitude    km            3.000|        10.000
       idle          10.2 W     Shock        g         4       |     40
       seek               W     Rotation   RPM      3323
       read/write         W     Acoustic   dBA        50
       spin-up            W     ECC        Bit   32,WITH 11BIT BURST COR
                                MTBF         h      20000
                                Warranty Month
Lift/Lock/Park     NO           Certificates                                  

**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
EPSON    HMD-726A  PRODUCT MANUAL MK3700-S 06-86

  +---------------------------------------------------------+
  |                                                         |XX J2
  |                                                         |XX Power
  |                                                         |
  |                                                         |XX I
  |                                                         |XX N
  |                                                         |XX T
  |                                                         |XX E
  |                                                         |XX R
  |                                                         |XX F
  |                                                         |XX A
  |                                                         |XX C
  |                                                         |XX E
  |                                    SS2         SS1      |XX
  |                                8--------0   8--------0  |XX J1
  +--------------------------------+--------+---+--------+--+





**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
EPSON    HMD-726A  PRODUCT MANUAL MK3700-S 06-86

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

 SS1  Termination
 ----------------
 ALL CLOSED  Activate line termination


 SS2  Drive Select
 -----------------
                            PINS
      |  0   |  1   |  2   |  3   |  4   |  5   | 6    |  7
   ---+------+------+------+------+------+------+------+-----
 S  0 |CLOSED|OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |OPEN
 C  1 |OPEN  |CLOSED|OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |OPEN
 S  2 |OPEN  |OPEN  |CLOSED|OPEN  |OPEN  |OPEN  |OPEN  |OPEN
 I  3 |OPEN  |OPEN  |OPEN  |CLOSED|OPEN  |OPEN  |OPEN  |OPEN
    4 |OPEN  |OPEN  |OPEN  |OPEN  |CLOSED|OPEN  |OPEN  |OPEN
 I  5 |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |CLOSED|OPEN  |OPEN
 D  6 |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |CLOSED|OPEN
    7 |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |OPEN  |CLOSED



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
ESPON    HMD-726A  PRODUCT MANUAL MK3700-S 06-86

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

 Installation direction
 ----------------------

     horizontally                           vertically
   +-----------------+             +--+                       +--+
   |                 |             |  +-----+           +-----+  |
   |                 |             |  |     |           |     |  |
 +-+-----------------+-+           |  |     |           |     |  |
 +---------------------+           |  |     |           |     |  |
                                   |  |     |           |     |  |
      x           x                |  |     |           |     |  |
 +------x------x-------+           |  +-----+           +-----+  |
 +-+------x--x-------+-+           +--+                       +--+
   |       xx        |
   |     x    x      |
   +---x--------x----+
     x            x


 Recommended orientation is vertical on either long side or
 horizontal with the PCB down or vertical with front bezel up or down.
 The prohibited orientation is horizontal with the PCB up.


 Mounting screws
 ---------------
 There are 8 mounting tapped holes on the mounting frame. The drive
 will be mounted using UNC *6-32 or M-3 or M-4 screws (both types are
 available), with 3.5mm (0.14 inches) maximum penetration.


 Mounting Clearance
 ------------------
 The EPSON HMD-726A is designed to withstand shocks and vibrations at
 greater levels. However, to take full advantage of the shock
 absorbers, it is necessary to provide a clearance of 2.5mm or 0.1
 inch on all sides of the drive. This clearance allows for movement of
 the drive during accelaration and also free air flow for ventilation.


 Electrical Interface
 --------------------
 The electrical interface consists of two parts, each of which is
 physically separated.

 (1) Interface Signals (J1/P1)
 (2) DC Power Input (J2/P2)

 All Interface signal lines are digital (terminated open collector
 TTL) and provide signals either to or from the drive via a 50 pin
 connector J1/P1. Connector J2/P2 provides the drive with DC powers
 (+12V and +5V).

 Flat Cable or Twisted Pair, max 20 Feet
 True or Low Level:   0.0 VDC to 0.4  VDC, 1 = -48 mA (max)
 False or High Level: 2.5 VDC to 5.25 VDC, 1 = +250 A (open collector)


 J1/P1 Connector
 ---------------
 Connection to J1 is through a 50-pin flat ribbon connector. The
 recommended mating connector is the AMP P/N 88551-5 cable connector.


 J2/P2 Connector
 ---------------
 DC power connector J2 is a 4-pin AMP Mate-N-Lok connector, mounted on
 the Pronted Circuit Board. The recommended mating connector for P2 is
 AMP P/N 1-480424-0 utilizing AMP pins P/N 350078-4.

      +------------+   pin 1    +12 VDC
      | 4  3  2  1 |   pin 2    +12 Volts Ground Return
      +------------+   pin 3    + 5 Volts Ground Return
                       pin 4    + 5 VDC


 Installation
 ------------

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

                                          Drive #0
  +---HOST------+                 +--------------+--+
  |             +--+-SCSI-BUS-----+ J1           |OP|
  |             |  |       +------+ J2           +--+
  |             |  |       |      +-----------------+
  +-------------+  |       |              Drive #2
                   |       |      +--------------+--+
                   o-------+------+ J1           |OP|
                   |       o------+ J2           +--+
                   |       |      +-----------------+
                   |       |
                   |       |
                   |       |              Drive #7
                   |       |      +--------------+--+
                   +-------+------+ J1           |CL|
                           o------+ J2           +--+
        ---DC-VOLTAGE------+      +-----------------+

 CL = SHUNT BLOCK SS1 ALL SHORTED
 OP = SHUNT BLOCK SS1 ALL OPEN



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
EPSON    HMD-726A  PRODUCT MANUAL MK3700-S 06-86

 Introduction
 ------------
 The EPSON HMD-726A is a 20-Megabyte intelligent 3-5 nch half height
 hard disc drive which communicates with a host computer via the small
 computer system Interface (SCSI).

 Feature:

 1. The drive and controller electronics within the standard 3.5" form
     factor.

 2. The highly efficient rotary actuator and drive circuits achieve
    low power consumption.

 3. Thermal off-track compensation system achives 910 tpi with
    excellent repeatability.

 4. Hardware 32 bit ECC polynominal with up to 11 bit burst
    correction.

 5. Reliability is enhanced by selected with 20,000 hours MTBF.


 Seek Time
 ---------
       +----------------------------------+--------+
       |Track-to-Track         msec. typ. |  18    |
       +----------------------------------+--------+
       |Average                msec. typ. |  80    |
       |                       msec. max. | 150    |
       +----------------------------------+--------+
       |Latency                msec. avg. |   8.5  |
       +----------------------------------+--------+


 Media Defect
 ------------
 Maximum Defects Per Surface         10
 Maximum Defects Per Drive           32
 Cylinder Zero certified Defect Free


