M 8 0 5 1 S    MINISCRIBE

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                                                      Native|  Translation
Form                 3.5"/HH               Cylinders     739|     |     |
Capacity form/unform    41/   51 MB        Heads           4|     |     |
Seek time   / track  30.0/ 8.0 ms          Sector/track   28|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer             1 KB DUAL-PORTED  Landing Zone
Data transfer rate    1.000 MB/S int       Bytes/Sector      512
                            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 80
       standby            W     Altitude    km    -0.061  3.048|        12.192
       idle           8.0 W     Shock        g        10       |     40
       seek               W     Rotation   RPM      3484
       read/write         W     Acoustic   dBA        45
       spin-up            W     ECC        Bit   32
                                MTBF         h      30000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC380,TUV,UL478,VDE 

                        L   A   Y   O   U   T

  |                               1---J4        1---J5    ++|XXI
  |                               +---+         +---+     |||XXN
  |                                                       |||XXT
  |                                                    RP3++|XXE
  |                                                       ++|XXR
  |                                                       |||XXF
  |                                                       |||XXA
  |                                                    RP2++|XXC
  |                                                       ++|XXE
  |                                                       |||XX
  |                                                       |||XX
  |                                                    RP1++|XX
  |                                                         |
  |                                                         |XXPower
  |                                                         |XXJ3

       |                                  |
       |                                  |
       |+---------- - - - - -----1+       |
       |+--SCSI------ -|X|- - ----+XXXXXX||
       |               +-+        +Power-+|
       +--             LED              --+


                      J   U   M   P   E   R   S

 Jumper Setting

 J4 Addressing
   | | +-- SEL 0
   | +---- SEL 1
   +------ SEL 2

      | SCSI ID  |        Jumpers        | Address selection on
      |          | SEL2  | SEL1  | SEL0  | the 8051S drive is
      +----------+-------+-------+-------+ accomplished by the
      |    0     | OPEN  | OPEN  | OPEN  | use of three jumpers
      |    1     | OPEN  | OPEN  | CLOSED| at J4:
      |    2     | OPEN  | CLOSED| OPEN  | SEL 0 (LSB)
      |    3     | OPEN  | CLOSED| CLOSED| SEL 1
      |    4     | CLOSED| OPEN  | OPEN  | SEL 2 (MSB)
      |    5     | CLOSED| OPEN  | CLOSED|
      |    6     | CLOSED| CLOSED| OPEN  |
      |    7     | CLOSED| CLOSED| CLOSED|
 Communication on the SCSI bus is allowed between only two (2) devices
 at any given time. There is a maximum of eight (8) SCSI devices. Each
 SCSI device has a SCSI ID bit assigned. When two (2) SCSI devices
 communicate on the SCSI bus one acts as an initiator and the other as
 a target. The initiator originates and operation and the target per-
 forms the operation. An initiator may address up to eight (8) logical
 units (LUN) attached to one target. The 8051S drive has only one
 logical unit attached (LUN = 0).

 J5  Mode Jumpers
   | | +-- E
   | +---- D
   +------ Disable Parity

 Disable Parity CLOSED = disabled

 J5-E Invokes Offline Diagnostics Following Reset, which consits of
      infinite seek tests (random or oscillating).

 J5-D Diagnostic mode (Internal use only).

 Diagnostic and Exercise Routines
 The microprocessor performs a series of "wake up" diagnostics upon
 application of power. If an error is detected, the processor will
 flash a warning by blinking the Activity LED. Some errors are fatal
 in that they do not return to the program until power is cycled.

 If no errors are detected, the processor tests Jumper E to determine
 its state (open or closed). Briefly, Jumper E (Drive Exercise
 Options) is as follows:

 The jumper is left open for normal (online) operations. It is also
 used to run burn-in code. If the jumper is closed, (and left closed)
 the normal burn-in (oscillating seeks) program will be run. If this
 jumper is closed and opening during the code level display, the
 random seek routine is run.

 Power-up sequence is as follows:

 1. Apply power.
 2. The microprocessor runs power on diagnostics.
 3. Test Jumper E. If open, go to normal operation. If closed,
    continue to Step 4.
 4. Diagnostic Mode Routine.

    Get here if diagnostic Jumper E is installed at powerup time. This
    routine flashes the revision level in the LED. A delay of 1 1/4
    seconds is the followed by a delay of 4 seconds with the LED on.
    The diagnostic Jumper E is checked following these delays and
    saved for future use. A recal is then done, and a seek to the
    maximum cylinder. A code of '1' is then flashed. A seek to
    cylinder zero is done and the LED is then turned on and remains
    on. If an error was detected during the recal or these two seeks,
    the routine hangs with error code 'D' being flashed. If no error
    was detected, the LED remains on and the routine performs either
    random seeks (Jumper E was removed during above delays) or
    oscillating seeks (Jumper E remained on during above delays). If
    an error is detected during the oscillating or random seeks, an
    error code of 'D'is flashed, and the routine restarts at the recal

 Code Definition
  0   Interface Processor RAM Check/Servo Processor RAM Check
  1   Interface Processor ROM Check/Data Sequencer Check
  2   Interface Chip Diagnostic Failure
  3   Not Used
  4   Servo Processor Not Ready
  5   Spin Speed Out of Range
  6   Recal Failure/Hard Reset Failure/Spin up Check
  7   Servo Sync Check
  8   Mismatched Interface-Servo Processor Firmware Levels
  9   Servo Track Follow Lost
  A   Servo Processor RAM Check/Servo Demod Chip Failure
  B   Servo Processor Failure
  C   Interface to Servo Processor Command Timeout Failure
  D   Seek or Recal Failure
  E   Servo Processor Lost Hall Transitions
  F   Unexpected Interrupt from Processor


                      I   N   S   T   A   L   L

 Notes of installation

 Drive Orientation
 The drive may be mounted in any attitude.

 Mounting Configuration
 The Miniscribe 8051S quarter size drives are designed to be used in
 applications where the unit may experience shock and vibration at
 greater levels than larger and heavier disk drives.

 Two features which allow greater shock tolerance are the rugged media
 and shock mounts. To take full advantage of the shock mounts,
 however, it is necessary to provide a minimum of 0.1 inch clearence
 on both the top and sides of the drive. This clearence allows for
 movement of the drive during acceleration.

 The drive is mounted using 6-32 screws, 1/8 inch maximum penetration.
 The customer should allow adequate ventilation for the drive to en-
 sure reliable drive operation over the operating temperature range.

 Mechanically isolated mounting points
 Four (4) side mounting and four (4) base mounting points are
 provided to the customer. Each mounting point is mechanically isola-
 ted from the head-disk assembly.

 SCSI Connector
 A 50 pin flat ribbon connector is provided at J1. The 3M P/N
 3425-3000 cable connector is recommended. All signals are low true
 and all odd pins are tied to Ground (except pin 25).

 TermPower (Pin 26) is +5 volts thru a 1 amp microfuse. Loss of this
 fuse will result in the disks drive appearing dead. RESERVING the
 connector with pin 25 grounded will cause this fuse blow.

 J3 DC Power Connector
 DC power connector (P3) is a 4 pin AMP Mate-N-Lok Connector, mounted
 on the PCB.

 The recommended mating connector (J3) is AMP P/N 1-480424-0 utilizing
 AMP pins P/N 350078-4.

       +------------+    1 = +12 Volts DC
       | 4  3  2  1 |    2 = +12 Volts Ground Return
       +------------+    3 = + 5 Volts Ground Return
                         4 = + 5 Volts DC

 Electrical Interface
 SCSI uses single-ended drivers and receivers which allow a maximum
 cable length of 20 feet (6 meters) from the first to the last
 device (up to 8 devices) on the bus.

 All assigned signals are terminated with 220 ohms to +5 volts and
 330 ohms to ground at each end of the cable. All three (3) terminator
 networks on the 8051S are removable.

 All signals driven by the drive are open collector and have the
 output characteristics as follows.

 Signal Assertion                  0.0 VDC to 0.8 VDC
 Max. Driver Output                48mA (sinking) at 0.5 VDC
 Signal Negation                   2.5 to 5.25 VDC

 All signals received by the drive shall have the following input

 Signal True                       0.0 V DC to 0.8 V DC
 Maximum Total Input Load          -0.4 mA @ 0.4 V DC
 Signal False                      2.5 to 5.25 V DC
 Minimum Input Hyteresis           0.2 V DC


                      F   E   A   T   U   R   E  S

 The MiniScribe 8051S (Small Computer System Interface - ANSI
 X3.131-1986) series of 3 1/2 inch disk drives are half height random
 access storage devices of 42 Megabytes of formatted data (51 MB un-
 formatted) containing 2 plated disks and utilizing Winchester style
 flexure technology.

 High performance and high unit reliability are achieved by the
 utilization of a proven microprocessor spin control and rack-and-
 pinion stepper mechanism. The heads, disks and actuator assemblies
 are within a sealed enclosure containing recirculating and breather
 filters to supply clean air and equalized pressure to the head and
 disk environment. Quality mechanical construction with a sophistica-
 ted single printed circuit board allows for maintenance-free
 operation throughout the life of the drive.

 The 8051S series disk drive uses the industry standard Small
 Computer System Interface (SCSI) compatible interface capable of up
 to 1 Megabyte/second (8 megabits/second) data transfer rate. The
 drive also features power up, user invoked or offline diagnostics and
 has full support of disconnection. Defect handling is entirely
 transparent to the host system as well as seek retry and error
 correction. The 8051S uses imbedded servo technology.

 The unit size and shock mounting are identical to the industry
 standard half height 3 1/2 mini floppy mounting dimensions and it
 uses the same power connector.

 Seek Time
       |                                  | 8051S  |
       |Track-to-Track         msec. typ. |   8    |
       |Average                msec. typ. | <30    |
       |                       msec. max. | <60    |
       |Latency                msec. avg. |   8.61 |

 Media Defect Criteria
 All defects are preassigned from the factory.

 Host Interface and Data Buffer
 The host interface and data buffer are integrated in one single
 semicustom circuit with the following features:

 ANSI X3.131-1986 compatible (SCSI) Host interface operating in Target
 mode only.

 Capable of Arbitration and disconnection.

 Parity generation and checking (user selectable).

 Dual ported 1024 bytes buffer.

 Read/Write Electronics
 One integrated circuit is mounted within the sealed enclosure in
 close proximity to the read/write heads. Its function is to provide
 one (1) of four (4) head selection, read preamplification and write
 drive circuitry.

 Drive Mechanism
 A brushless DC direct drive motor rotates the spindle at 3484 RPM.
 The motor/spindle assembly is dynamically balanced to provide minimal
 mechanical runout to the disks. A dynamic brake is used to provide a
 fast stop to the spindle motor when power is removed.

 Air Filtration System
 Within the sealed enclosure, a 0.3 micron filter, coupled with a
 breather filter, provides over the drive life a clean, above
 atmospheric pressure environment to the heads and disks.

 Head Positioning System
 The position of four (4) read/write heads are controlled by a moving
 magnet rotary actuator.

 The Miniscribe drive is a precision product. During handling the unit
 must not be dropped, jarred or bumped. Otherwise, damage to the heads
 and disks may occur. When the drive is removed from the Miniscribe
 shipping container and not immediately secured within a chassis
 through its shock mounts, it must be stored on a padded, grounded,
 antistatic surface.

 Failure to comply with the above procedure will render null and void
 all warranties.