                 MICROPOLIS 1670 DISK DRIVE
                       SPECIFICATIONS

                                       Model Number
Unformatted Capacity:     1673-4     1673-5     1674-6     1674-7

  Total Mbytes             104.0      130.0      156.1      182.1
  Disk Platters                3          3          4          4
  Read/Write Heads             4          5          6          7
  Cylinders               ---------------- 1249 -----------------
  Bytes per track         -------------- 20,832 -----------------

Formatted Capacity

  Total Mbytes              90.3      112.6      135.5      157.8
  Bytes per Sector        ----------------- 512 -----------------
  Sectors per Track       -----------------  36 -----------------

PC Setup

  When using SCSI in a PC, the most common method is to run your 
  setup program and define No Drives Present. The SCSI Host Adapter
  will automatically self-configured on power-up. To install the
  drive, follow the manufacturer's instructions to use the on-board
  BIOS routine or software that was supplied with the Host Adapter.

Performance Specifications

  Seek Time (including settling time)     Track-to-Track   4 msec
                                          Average         16 msec
                                          Maximum         37 msec
  Average Rotational Latency                            8.33 msec
  Rotational Speed                              3600 rpm +/- 0.5%
  Data Transfer Rate at Interface
    Synchronous                                    4.0 Mbytes/sec
    Asynchronous                                   1.6 Mbytes/sec
  Internal Data Rate                                 10 Mbits/sec
  MTBF                                              150,000 hours
  Positioner                     Fully balanced rotary voice coil
  Parking                                 Automatic park and lock

General Functional Specifications

  Interface                                                  SCSI
  Supports Common Command Set
  Write Precompensation Start Cylinder                       1249
  Reduced Write Current Start Cylinder                       1249
  Landing Zone                                               1249
  Mounting Plane                                  Any orientation

Power Requirements

  +12V +/-5%                                            0.9A  Avg
                                       (2.0A max during start-up)
  +5V +/-5%                                              1.0A avg
  Power dissipation, typical                             15 Watts

7. Drive Addressing and Interface Termination


              _ID2
             |  _ID1
             | |  _ID0
             | | |                        Pin 1
         J2  | | |              J1            |       J3 (Power 
      ____________   __________________________    ________connector on
    _|            |_|                          |  |W14   W9| underside 
   | |____________| |__________________________|__|   W3   | of board
   |                                                       |
   |                W31    W2 W1                           |
   |        +----------+                                   |
   |        | U39      |        RN9                        |
   |        | SCSI     |                                   |
   |        |   PROM   |                                   |
   |        +----------+                                   |
   |                                                       |
   |                                                       |
   |                                                       |
   |                                 Component Side        |
   |                                                       |



ID0, ID1, ID2 SCSI Address Jumpers
  The SCSI ID (drive address) jumpers are identified as ID0, ID1,
  and ID2. ID selection is binary, as shown in the table below.

   SCSI              Jumpers
  Address        ID2   ID1   ID0
  -------        ---   ---   ---
     0           out   out   out
     1           out   out    in
     2           out    in   out
     3           out    in    in
     4            in   out   out
     5            in   out    in
     6            in    in   out
     7            in    in    in

  For multiple drive installations, on one Host Adapter, each drive
  must have a unique address. Drives are configured as SCSI ID 0 at
  the factory.

RN9 Interface Terminator
  The Interface Terminator factory installed at RN9 provides
  proper termination for the interface lines. When daisy-chaining
  multiple drives, leave the terminator installed only in the last
  physical drive (or drives) on the daisy chain cable; remove the
  terminator from each of the other drives (or the host computer).

W1, W2 Terminator Option
  W1 and W2 select the source of terminator power (+5V) for the
  interface terminator. If a jumper is installed at W1 and no
  jumper is installed at W2 (the factory default configuration),
  the drive provides terminator power. This configuration is used
  for PC/AT applications. If no jumper is installed at W1 but a
  jumper is installed at W2, terminator power must provided by the
  host computer system via interface connector J1, pin 26.

W3, Spindle Option
  W3 selects the spindle control option. If W3 is installed, the
  drive waits for a Start Spindle command after power is applied
  to start the spindle motor. If W3 is not installed (the factory
  default configuration), the drive automatically starts the
  spindle motor at power-on. W3 is not installed for PC/AT
  installations.

W9 Bus Parity Option
  W9 selects the parity check option. If W9 is installed, the drive
  neither generates nor detects parity. If W9 is not installed (the
  factory default configuration), the drive generates parity and
  enables parity detection. W9 is usally not installed for PC/AT
  applications. Verify the correct configuration required by your
  Host Adapter.
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