
H M D - 7 6 5    EPSON
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders     615|     |     |
Capacity form/unform    42/      MB        Heads           4|     |     |
Seek time   / track  80.0/18.0 ms          Sector/track   34|     |     |
Controller           IDE / XT              Precompensation
Cache/Buffer               KB              Landing Zone
Data transfer rate    0.938 MB/S int       Bytes/Sector      512
                      0.938 MB/S ext
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C         4 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         8       |     40
       seek               W     Rotation   RPM      2650
       read/write         W     Acoustic   dBA        50
       spin-up            W     ECC        Bit   32,WITH 11BIT BURST COR
                                MTBF         h      20000
                                Warranty Month
Lift/Lock/Park     YES          Certificates                                  

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EPSON    HMD-755/765  PRODUCT MANUAL MK3-705-000-00-REV.0 9/87

  +---------------------------------------------------------+
  |                                                         |XX Power
  |                                                         |XX
  |                                                         |
  |                                                         |
  |                                                         |XX I
  |                                                         |XX N
  |                                                         |XX T J1
  |                                                         |XX E
  |                                                         |XX R
  |                                                         |XX F
  |                                                         |XX A
  |                                                         |XX C
  |                                                         |XX E
  |                                                         |XX
  |                                                         |XX
  +---------------------------------------------------------+




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                      J   U   M   P   E   R   S
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EPSON    HMD-755/765  PRODUCT MANUAL MK3-705-000-00-REV. 0 9/87

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

 Drive Set Up
 ------------
 In the 2-drive operation, the two drives are assigned Drive 0 or
 Drive 1 by shunt block SS1. The host accesses Drive 0 via I/O address
 port 320H through 323H or Drive 1 via I/O address port 324H through
 327H.

 As shipped, Drive 0 is selected.

 Pin Pair    Drive Number when shorted
    0                     0
    1                     1



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EPSON    HMD-755/765  PRODUCT MANUAL MK3-705-000-00-REV. 0

 Notes on Installation
 =====================

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

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

 There are 5 possible mounting orientations;

    - Vertical on either side
    - Horizontal with PCB down

 Do not mount horizontally with the PCB up!


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


 Mounting Clearance
 ------------------
 The drive is designed to withstand high level shocks and vibrations.
 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
 acceleration and also free air flow for ventilation.


 Cable Interconnection (2 Drive System)
 --------------------------------------

                         Adapter Card
          +-------------+ |            +----------+
          |             +--+           |Drive 0   |
          |             |  |         +-+          |
          |   HOST      |  +---------+ |J1        |
          |             +--+         +-+          |
          |             |              +----------+
          |             |              +----------+
          |             +--+           |Drive 1   |
          |             |  |         +-+          |
          |             |  +---------+ |J1        |
          |             +--+         +-+          |
          +-------------+ |            +----------+
                         Adapter Card


 Electrical Interface
 --------------------
 All interface signal lines are TTL compatible and provide signals
 either to or from the drive via a 40 contact edge connector J1/P1.

 Note about connector pin 39: This open collector output drives an
 external LED activity indicator.



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EPSON    HMD-755/765  PRODUCT MANUAL MK3-705-000-00-REV. 0


 Introduction
 ------------
 The EPSON HMD-755/765 are 21.4-Megabyte / 42.6-Megabyte intelligent
 3.5 inch half height hard disk drive which communicates with a host
 computer vai IBM-XT Bus.

 Features:

   - Drive and controller electronics within the standard 3.5" form
     factor.

   - Highly efficient rotary actuator and drive circuits achieve low
     power consumption.

   - Thermal off-track compensation achieves 910 tpi with excellent
     repeatability.

   - Hardware 32 bit ECC polynomial with up to 11 bit burst correction

   - Reliability is enhanced by selected parts with 20,000 hours MTBF


 HMD-755
 -------
 Read/Write Heads   2**
 Discs              1**

 ** Using another Firmware, HMD-755 can keep compatibility with
 HMD-725 at Read/Write Head and Disc number. (4 Read/Write Heads and
 2 Discs.)


 Seek Time
 ---------
       +----------------------------------+--------+
       |Track-to-Track         msec. typ. |  18    |
       +----------------------------------+--------+
       |Average                msec. typ. |  80    |
       |                       msec. max. | 150    |
       +----------------------------------+--------+
       |Latency                msec. avg. |  11.3  |
       +----------------------------------+--------+


 Media Defect criteria (as shipped from EPSON)
 ---------------------------------------------
 Maximum Defects per Logical Head    10
 Maximum Defects per Drive           32
 Cylinder zero certified Defect Free


 Reliability
 -----------
 MTBF                      20,000 poh
 Preventive Maintenance    none
 MTTR                      30 minutes
 Component Life            5 years


