MICROPOLIS 2105A DISK DRIVE
                        SPECIFICATIONS

                                       Model Number
Unformatted Capacity:                    2105-15 

Total Mbytes            ---------------  650 -----------------       
Disk Platters           -----------------  5 -----------------       
Read/Write Heads        -----------------  8 -----------------        
Cylinders               --------------- 1760 -----------------        
Bytes per track         ----------- VARIABLE -----------------

Formatted Capacity  

Total Mbytes            ---------------- 560 -----------------        
Bytes per Sector        ---------------- 512 -----------------        
Sectors per Track       ----------- VARIABLE -----------------

Performance Specifications  

  Seek Time                       Adjacent Track         1.5 msec
    (including settling time)     Average               10.0 msec
                                  Maximum                 25 msec

  Average Rotational Latency                            5.56 msec
  Rotational Speed                              5400 rpm +/- 0.5%

  Data Transfer Rate at Interface            Up to 5.6 Mbytes/sec

  Internal Data Rate                                 24 to 40 MHz

  MTBF                                              300,000 hours
  Positioner                     Fully balanced rotary voice coil
  Parking                                 Automatic park and lock

 General Functional Specifications  

  Interface                                                AT/IDE
  Supports Full Common Command Set                            YES
  Mounting Plane                                  Any orientation

Power Requirements  

  +12V +/-5%                                           0.75A  Avg
                                        (2.0 max during start-up)
  +5V +/-5%                                              1.0A avg
 
  Power dissipation, typical                           11.5 Watts



7. Drive Options

      ____   _______________________   ________  
     # J2 # #         J1            # #   J3   #  
     #    #_#_______________________#_#________#  
     #                                         #
     #               RESERVED                  #
     #               # # #                     #
     #           : : : : :                     #
     #           # #                           #
     #          W1 #                           #
     #            W2                           #
     #                                         #
     \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

      /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
     #           LED                           #
     #________##_______________________________#
     

W1, W2 Jumpers (Master / Slave Selection)
    The interface allows up to two drives (a Master and one Slave) to be 
    attached to the AT/IDE bus. The following table shows the configurations.

       W1     W2    Description                                         
    +------+------+-------------------------------------------------------+
    # OUT  #  IN  # Drive is Master, Slave is present                     #
    +------+------+-------------------------------------------------------+
    #  IN  # OUT  # Drive Slave                                           #
    +------+------+-------------------------------------------------------+
    # OUT  # OUT  # Drive is Master                                       #
    +------+------+-------------------------------------------------------+

DRIVE IS MASTER, SLAVE IS PRESENT
     Specifies the Master drive (Drive 0) when two 2112A drives are used in the 
     system. The other drive is the Slave.

DRIVE IS SLAVE
     Specifies the Slave drive (Drive 1) when two 2112A drives are used in the 
     system. The other drive is the Master.

DRIVE IS MASTER
     Specifies the Master drive (DRIVE 0) when one 2112A drive is used in a 
     system.