Hard Drive: SEAGATE: ST251R-0 62MB 5.25"/HH RLL ST412

S T 2 5 1 R - 0    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/HH              Cylinders     820|     |     |
Capacity form/unform    62/      MB        Heads           6|     |     |
Seek time   / track  40.0/     ms          Sector/track   26|     |     |
Controller           RLL / ST412           Precompensation 65535
Cache/Buffer               KB              Landing Zone      819
Data transfer rate    0.938 MB/S int       Bytes/Sector      512
                      0.938 MB/S ext
Recording method     RLL                            operating  | non-operating
                                                  -------------+--------------
Supply voltage                  Temperature *C                 |
Power: sleep              W     Humidity     %                 |
       standby            W     Altitude    km                 |
       idle               W     Shock        g                 |
       seek               W     Rotation   RPM      3600
       read/write         W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h      70000
                                Warranty Month        12
Lift/Lock/Park     YES          Certificates                                  

Jumpers

SEAGATE ST213/ST225/ST225R/ST238R/ST250R PRODUCT MANUAL 36025-003

Jumper setting
--------------
x = Factory setting

 JP7  Drive select  Configuration Jumper block
 ----------------------------------------------
      +-------------+------+------+------+------+
      |Drive Select | 9-10 |11-12 |13-14 |15-16 |
      +-------------+------+------+------+------+
      |Drive 4      |CLOSED|OPEN  |OPEN  |OPEN  |
      |Drive 3      |OPEN  |CLOSED|OPEN  |OPEN  |
      |Drive 2      |OPEN  |OPEN  |CLOSED|OPEN  |
      |Drive 1      |OPEN  |OPEN  |OPEN  |CLOSED|
      +-------------+------+------+------+------+
 The Drive Select line enables the controller to select and adress
 the drive. Control cable interface options may use either a daisy-
 chain or radial configuration.

 JP7  Manufacturing test
 -----------------------
 x     7- 8   OPEN  Do not install a jumper on the Manufacturing Test
                    jumper on the user configuration jumper block.
                    This is a test function and used during the manu-
                    facturing process ans is not recommended for field
                    use. When the pins are shorted, the stepper motor
                    will continuously seek between Track 0 and the
                    maximum cylinder and will ignore control signals
                    via the interface.

 JP7  Write Fault
 ----------------
 x     5- 6   OPEN  The Write Fault signal may be internally latched.
                    It may be enabled by shorting pins 5-6 at J7. This
                    latch may be cleared when Drive Select goes false
                    (if selected). The standard configuration, with
                    the shorting block removed, causes Write Fault to
                    go false when Write Gate goes false.
                    Not required for standard operation.

 JP7  Recovery Mode
 -----------------
 x     3- 4   CLOSE Recovery Mode is a read/write head microstepping
                    option on the ST225R and ST250R. It is enabled by
                    shorting pins 3-4 at J7. THE ST225R AND ST250R ARE
                    SHIPPED WITH THIS OPTION ENABLED.

Recovery Mode is initiated when the controller asserts the Recovery
Mode line true at the interface. This changes the step line to a
microstep function after 100 nsec. A step pulse will now cause Seek
Complete to go false 100 nsec. after the drive receives the pulse.
The drive then microsteps off-track using the optimum algorithm,
allowing time for the read/write heads to settle and then takes the
Seek Complete line true.

The controller may then read data. If data is not read correctly, the
controller may issue an additional step pulse. Up to 2 microstep
algorithms may be accessed before the sequence is repeated.

When data is read correctly, the controller exits Recovery Mode by
taking the Recovery Mode line false at the interface. The drive will
then return the heads to the nominal position by taking Seek Complete
false, allowing time for the heads to settle, and resasserting Seek
Complete.

 JP7  Radial/Daisy-Chain Mode
 ----------------------------
 x     1- 2   OPEN  Daisy-Chain-Configuration
                    A Daisy-Chain configuration allows connection of
                    a maximum of two drives on a common control cable.
                    A separate data cable is required for each drive.
                    The last drive in the chain (physically farthest
                    from the controller) requires termination. All
                    other drives should not be terminated. The maxi-
                    mum permitted cable length from the controller to
                    the last drive is 10ft (0.31m).
       1- 2   CLOSE Radial Configuration
                    To configure the drive radially, install a jumper
                    on pins 1 and 2 of the user configuration jumper
                    block. If you configure the drive radially, leave
                    the resistor terminator packs installed on all
                    drives. Each radially connected drive has its own
                    control and data cable. Drives in this configu-
                    ration always remain selected.

 J3  DC Power and pin connector assignments
 ------------------------------------------
      +------------+   pin 1    +12 VDC
      | 1  2  3  4 |   pin 2    +12 VDC Gnd
      +------------+   pin 3    + 5 VDC Gnd
                       pin 4    + 5 VDC