
P R A I R I E   2 4 2 X T    PRAIRIETEK
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 2.5"/SLIMLINE         Cylinders     615|     |     |
Capacity form/unform    42/      MB        Heads           4|     |     |
Seek time   / track  23.0/ 8.0 ms          Sector/track   34|     |     |
Controller           IDE / XT              Precompensation
Cache/Buffer               KB              Landing Zone
Data transfer rate    1.250 MB/S int       Bytes/Sector      512
                            MB/S ext
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5 V          Temperature *C         5 55    |    -40 70
Power: sleep              W     Humidity     %                 |     10 90
       standby        0.1 W     Altitude    km    -0.305  3.048| -0.305 12.192
       idle           1.1 W     Shock        g                 |
       seek               W     Rotation   RPM      3307
       read/write     2.5 W     Acoustic   dBA
       spin-up        3.5 W     ECC        Bit   YES
                                MTBF         h     100000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,IEC435,UL1950,VDE        

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                        L   A   Y   O   U   T
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PRAIRIE. PRAIRIE 242  PRODUCT MANUAL 70031C REV. X2, 19/2/1991

  +-------------------------------------------------------+
  |         +-----++-----++-----+     +------+            |
  |         |     ||     ||     |     |      |            |
  |         |     ||     ||     |     |      |            |XX
  |         |     ||     ||     |     |      |            |XX
  |         +-----++-----++-----+     |      |            |XX
  |                                   +------+            |XX
  |                            +---------+                |XX
  |                            |         |                |XX
  |                            |         |                |XX
  |                            |         |                |XX
  |                            |         |                |XX
  |                            +---------+      +------+  |XX
  |                                  +-+        |      |  |XX
  | +-------+                        |:|E1      |      |  |
  | |       |                        +-+        |      |  |
  | +-------+                                   +------+  |
  +-------------------------------------------------------+



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                      J   U   M   P   E   R   S
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PRAIRIE. PRAIRIE 242  PRODUCT MANUAL REV. X2 70031C 19/2/1991

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

 Customer Options
 ----------------
 The host interface on the 242 can be set to run on either an AT or XT
 compatible system. The polarity of Pin 44 on the interface will de-
 termine XT or AT operation (+AT, -XT). When Pin 44 is grounded, the
 signal will enable the XT Mode.

 In AT mode, the 242 can operate as a single drive or in a dual drive
 (master/slave) configuration. The jumper trace E1 is shorted from the
 factory indicating a single drive or the master. In dual drive
 configuration, the E1 trace must be cut to indicate the second drive
 or slave.



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                      I   N   S   T   A   L   L
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PRAIRIE. PRAIRIE 242  PRODUCT MANUAL REV. X2 70031C  19/2/1991

 Notes On Installation
 =====================

 Mounting Configurations
 -----------------------
 The features which allow greater shock and vibration tolerance
 include the dynamically loaded heads, a fully balanced rotary
 actuator, and the low overall mass and weight of the drive and
 moving masses.

 Adequate ventilation must be provided to the drive to ensure reliable
 operation over the specified operating temperature range.

 The drive may be mounted in any attitude. It can be mounted either
 from the side or the bottom using four M2X.4 screws.

 The drive is available with two different connector systems.

 The connector 2A is a Dupont Mini Tek II, 2 x 2mm (Double Row) header
 consisting of 50 positions. Th eHost Interface and power are accessed
 through P1 to Pin 44. The recommended mating connector is Dupont part
 number 86991-144 or equivalent.

 The connector 2B is a KEL 8830B Series Plug with 0.05 inch spacing
 (Double Row) consisting of 50 positions. The Host Interface and
 power are accessed through P1 to Pin 44. The recommended mating
 connectors are KEL 8800 Series Receptacles (50 pin).


 Physical Decription
 -------------------
 The Model 242 Host Interface can be directly connected to the Host or
 can accommodate cable connection with a maximum length of 2 feet
 (610mm).


 Connector
 ---------
 On the DuPont header, the separate 4 pins are for factory test pur-
 poses and are not associated with the Host Interface. These pins
 should be left disconnected.

 On the KEL Plug, Pin 47 through 50 are for factory test purposes and
 these pins should be left disconnected. Additionally, Pin 45 should
 be connected to +5V return and Pin 46 should be connected to +5V
 supply.


 Electrical Description
 ----------------------
 All signal levels are TTL compatible. A logic "1" is > 2.0 volts. A
 logic "0" is from 0.00 volts to 0.70 volts.

 The interface between the drive adapter and the drive is called the
 Host Interface.



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                      F   E   A   T   U   R   E  S
**********************************************************************
PRAIRIE. PRAIRIE 242  PRODUCT MANUAL 70031C REV. X2  19/02/1991

 Key Features
 ------------
 Unique ramp loading mechanism for loading and unloading the disk
 heads during power-downs and periods of inactivity.

 User invoked low power modes and power-downs for power sensitive
 applications.

 High performance rotary voice coil actuator with embedded servo
 system.

 On-board controller for direct connection to a 44-pin interface.

 Microprocessor - controlled diagnostic routines that are
 automatically performed at power up.

 Internal air filtration system.

 Automatic error detection and correction.


 Functional Description
 ----------------------
 The Model 242 disk drive contains all the necessary mechanical and
 electronic components to interpret control signals, properly position
 the recording heads, read and write data, and maintain a contaminant
 free environment for the disks and recording heads.


 Read/Write and Control Electronics
 ----------------------------------
 The Model 242 has an integrated circuit attached to the flexible
 circuit connected to the actuator arm and read/write heads to provide
 one of four head selections, read preamplification, and write drive
 circuitry.

 The microprocessor controlled circuit board provides the remaining
 electronic functions including:

 - Read/Write Circuitry
 - Rotary Actuator Control
 - Interface Control
 - Power Management
 - Spin Speed Control
 - Automatic Head Unloading


 Error Correction
 ----------------
 The Model 242 performs internal error correction through the use of
 a polynomial capable of correcting one error burst with a maximum of
 11 bits per 512 byte block.


 Diagnostic Routines
 -------------------
 Upon power up the microprocessor circuitry of the Model 242 performs
 diagnostics. If an error is detected the drive will not come ready.


 Spin-Up/Down Operations
 -----------------------
 When power is applied to the drive, it will perform its diagnostics
 and come ready. To conserve power, it will accept commands, but will
 not spin up until it receives a command requiring a disk access (such
 as a Read, Write, Seek, Recal, etc.).

 When spinning up for the first time after application power, it will
 spin up and do a servo calibration which requires a total time of 5
 seconds (typically).


