
S T 2 7 7 N - 0    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 5.25"/HH              Cylinders     820|     |     |
Capacity form/unform    65/   77 MB        Heads           6|     |     |
Seek time   / track  38.0/ 8.0 ms          Sector/track   26|     |     |
Controller           SCSI1 SINGLE-ENDED    Precompensation
Cache/Buffer               KB              Landing Zone
Data transfer rate    0.938 MB/S int       Bytes/Sector      512
                      1.500 MB/S ext ASYNC
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 45    |    -40 60
Power: sleep              W     Humidity     %         8 80    |      5 90
       standby            W     Altitude    km    -0.305  3.050| -0.305  9.140
       idle               W     Shock        g        10       |     40
       seek               W     Rotation   RPM      3600
       read/write    12.0 W     Acoustic   dBA
       spin-up            W     ECC        Bit   32
                                MTBF         h      70000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,TUV,UL478,VDE        

**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
SEAGATE  ST251N/ST277N/ST296N  PRODUCT MANUAL 36034-003, REV.D

  +------------------------------------------------------++-+J2
  |                                                      || |Parity
  |                                                      || |SCSI ID
  |                                                      |+-+
  |                                                 +-+  |XX
  |                                                 | |  |XX SCSI
  |                                                 +-+  |XX Interface
  |                                      Resistor   +-+  |XX
  |                                      Terminator | |  |XX
  |                                      Packs      +-+  |XX
  |                                                 +-+  |XX
  |                                                 | |  |XX
  |                                                 +-+  |XX
  |                                                      |
  |                                                      |XX Power
  |                                                      |XX J3
  +------------------------------------------------------+




**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
SEAGATE  ST251N/277N/296N  PRODUCT MANUAL 36034-003, REV.D

 Jumper setting
 --------------

 J2   SCSI Bus Address
 ---------------------
             +-------+------+------+------+------+
             |SCSI ID|  P   |  4   |  2   |  1   |
             +-------+------+------+------+------+
             |   0   |  -   |OPEN  |OPEN  |OPEN  |
             +-------+------+------+------+------+
             |   1   |  -   |OPEN  |OPEN  |CLOSED|
             +-------+------+------+------+------+
             |   2   |  -   |OPEN  |CLOSED|OPEN  |
             +-------+------+------+------+------+
             |   3   |  -   |OPEN  |CLOSED|CLOSED|
             +-------+------+------+------+------+
             |   4   |  -   |CLOSED|OPEN  |OPEN  |
             +-------+------+------+------+------+
             |   5   |  -   |CLOSED|OPEN  |CLOSED|
             +-------+------+------+------+------+
             |   6   |  -   |CLOSED|CLOSED|OPEN  |
             +-------+------+------+------+------+
             |   7   |  -   |CLOSED|CLOSED|CLOSED|
             +-------+------+------+------+------+

 Jumpers are provided on the drive for selecting the SCSI bus address.
 The microprocessor accesses this information at power-on. The address
 jumpers are accessed only during the power-on sequence. If the SCSI
 address is changed, the drive must be powered off and on.
 Select the desired SCSI ID with Jumpers.


 J2   Parity Bit Option
 ----------------------
             +-------+------+------+------+------+
             |Parity |  P   |  4   |  2   |  1   |
             +-------+------+------+------+------+
             |Enable |CLOSED|  -   |  -   |  -   |
             +-------+------+------+------+------+
             |Disable|OPEN  |  -   |  -   |  -   |
             +-------+------+------+------+------+

 Some systems require parity bit checking. Consult the system confi-
 guration. The parity bit option jumper is located adjacent to the
 SCSI adress pins. Install the optional P-Jumper to enable Parity.


 50-Pin SCSI Connector Pin Assignments
 -------------------------------------
    Signal    Pin No.    Signal     Pin No.
    ----------------------------------------
    -DB(0)       2       Ground       28
    -DB(1)       4       Ground       30
    -DB(2)       6       -ATN         32
    -DB(3)       8       Ground       34
    -DB(4)      10       -BSY         36
    -DB(5)      12       -ACK         38
    -DB(6)      14       -RST         40
    -DB(7)      16       -MSG         42
    -DB(P)      18       -SEL         44
    Ground      20       -C/D         46
    Ground      22       -REQ         48
    Ground      24       -I/O         50
    Terminator  26
    Power

  Note: All odd pins, except pin-25 are connected to ground. Pin-25
        is not connected.



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



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
SEAGATE  ST251N/ST277N/ST296N  PRODUCT MANUAL 36034-003, REV.D

 Notes on installation
 =====================

 Drive mounting
 --------------

     horizontally             vertically
   +-----------------+   +--+             +--+ +------------------+
   |                 |   |  +-----+ +-----+  | |                  | x
   |                 |   |  |     | |     |  | x+----------------+x
 +-+-----------------+-+ |  |     | |     |  | ||x              x||
 +---------------------+ |  |     | |     |  | ||  x          x  ||
                         |  |     | |     |  | ||    x      x    ||
      x           x      |  |     | |     |  | ||      x  x      ||
 +------x------x-------+ |  +-----+ +-----+  | ||       xx       ||
 +-+------x--x-------+-+ +--+             +--+ ||     x    x     ||
   |       xx        |                         ||   x        x   ||
   |     x    x      |                         || x            x ||
   +---x--------x----+                         |x                x|
     x            x                           x++----------------++x
      UNACCEPTABLE!                                UNACCEPTABLE!
      Never install PC board on the Top!

 The drive may be mounted horizontally with the PC board down or on
 either side. Mounting vertically on either end is a prohibited orien-
 tation.
 The drive should not be tilted front or back, in any position, by
 more than 5*. For optimum performance, the drive should be formatted
 in the same position as it will be mounted in the host system.

 The mounting screws must not exceed inside the mounting feet more
 than 3.2 mm, measured from the outside surface of the foot.


 Shock and vibrations
 --------------------
 All shock and vibration specifications assume that the drive is moun-
 ted in an approved orientation with the input levels at the drive
 mounting screws.


 Shipping zone
 -------------
 Upon power-down, the read/write heads automatically move to the ship-
 ping zone. All portions of the Head/slider assembly park inboard of
 the maximum data cylinder.

 When power is applied, the heads will recalibrate to Track 0.


 FCC Verification
 ----------------
 These drives are devices which are intended to be contained solely
 within a personal computer or similar enclosure and not attached to
 an external device. As such, they are considered to be subassemblies
 even when individually marketed to the customer.


 SCSI Interface
 --------------
 Seagate intelligent drives feature an onboard SCSI-compatible con-
 troller. This embedded controller performs all of the functions that
 were previously implemented by the host-supplied controller. With the
 controller onboard, the diagnostic capabilities of the drive are en-
 hanced because the controller is able to optimize drive performance
 and error recovery.

 The embedded controller supports the SCSI interface as defined in the
 ANSI X3T9.2/82-2 document. The interface hardware is capable of
 transferring up to 1.5 Mbytes/sec. using asynchronous data transfer.
 Devices on the SCSI Interface are daisy-chained together using a
 common cable. Both ends of the cable are terminated. All signals on
 the interface are common between devices.


 SCSI cable
 ----------
 A 50-conductor flat cable or 25-conductor twisted pair cable is
 required. The maximum cable length is 6 meters (19.7 ft). Each SCSI
 bus connection may have a 0.1 meter (0.33 ft) maximum stub length.

 The characteristic impedance for unshielded flat or twisted pair
 ribbon cable should be 100    10%. A characteristic impedance greater
 than 90  is preferred for shielded cables.
 To minimize discontinuities and signal reflections it is desirable
 to minimize the use of cables of different impedances in the same
 bus.


 Connector Requirements
 ----------------------
 The drive connector is a 50-conductor Connector with two rows of 25
 male oins on 100 mil centers.

 The cable connector is a 50-conductor nonshielded connector consist-
 ing of two row of 25 female contacts on 100 mil centers.

 Input Noise
 -----------
 Maximum permitted input noise ripple: 100 mV (peak-to-peak)
 Maximum permitted input noise: 20 MHz.
 Ripple measured at the host system power supply across an equivalent
 8  resistive load on the +12 V line and an equivalent 3  load on the
 +5 V line.


 Handling and Static-Discharge Precautions
 -----------------------------------------
 After unpacking, and prior to system integration, the drive may be
 exposed to potential handling and ESD hazards. It is mandatory that
 you observe standard static-discharge precautions. A grounded wrist-
 strap is preferred. Handle the drive by the frame only and always
 rest the drive on a padded surface until it is mounted in the host
 system.


 Disc format
 -----------
 The ST251N-0 and the ST277N-0 disc format is flexible and supports
 either 512 or 1024 bytes/sector.
 The ST251N-1, ST277N-1 and ST296N disc format is flexible and sup-
 ports either 256, 512 or 1024 bytes/sector.


 Record interleave
 -----------------
 User-specific record interleaves are supported; from 1:1 (records
 formatted sequentially on the disk) through the number of records
 per track minus 1. This gives the user the ability to configure the
 drive for maximum performance within the operating environment.


 Onboard Drive Diagnostics
 -------------------------
 At power-on the drive will execute a series of diagnostic tests. Any
 failure will be indicated by a series of LED (front panel) flashes.
 The first failure will be preserved. The drive is ready to read/write
 if no error codes are received within 22 seconds.

 +-------+---------------------------------------------------------+
 |Flashes|Failures codes                                           |
 +-------+---------------------------------------------------------+
 |   1   |Microprocessor/Internal Memory Test                      |
 +-------+---------------------------------------------------------+
 |   2   |Microprocessor ROM Checksum Test                         |
 +-------+---------------------------------------------------------+
 |   3   |Controller Chip Test                                     |
 +-------+---------------------------------------------------------+
 |   4   |Controller Program RAM Test                              |
 +-------+---------------------------------------------------------+
 |   5   |Dat Buffer RAM Test                                      |
 +-------+---------------------------------------------------------+
 |   7   |Spindle Speed Test                                       |
 |       | If the drive is unable to reach and maintaine correct   |
 |       | spindle speed                                           |
 +-------+---------------------------------------------------------+
 |   4   |Read Record ID Mark                                      |
 |       | If the controller is unable to find and read an ID mark |
 |       | for any record                                          |
 +-------+---------------------------------------------------------+
 |   8   |Read Operating System Microcode From Drive               |
 |       | If the controller is unable to read the operating system|
 |       | from the drive                                          |
 +-------+---------------------------------------------------------+
 |   9   |Read Operating System Microcode From Drive               |
 |       | If the controller reads the operating system records,   |
 |       | but dertermines that they are invalid.                  |
 +-------+---------------------------------------------------------+


 Offline Self-test Routines
 --------------------------
 This product family supports a self-test routine that Seagate recom-
 mends for incoming inspection. This test may be run after the unit
 has successfully passed the power-on diagnostics.

 To enable the test, short the following pins to ground at the SCSI
 connector: 2, 12, 16 and 32.

 The self test has three parts. They will cycle in order until power
 or a ground jumper is removed, or until ten complete passes.

 The LED will remain ON during the test and will turn OFF if an error
 is detected or a jumper is removed. The LED will flash continuously
 if 10 passes are completed without error.

 PART ONE: All sectors in the user data area are read starting with
 logical block zero.
 PART TWO: This is a butterfly read/seek test. Starting at the center
 of the user data tracks, the unit will seek outward and inward by in-
 crements until the limits of the user data tracks are reached. A one
 track read is performed to verify position.
 PART THREE: This part performs a write/read compare on all sectors of
 the diagnostic cylinders using the data pattern 6DBh.
 The diagnostic cylinders are located at an inner region on each media
 surface. Any unrecoverable errors will terminate the test and turn
 off the LED.



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
SEAGATE  ST251N/ST277N/ST296N  PRODUCT MANUAL 36034-003, REV.D

 Formating and Defect Management
 -------------------------------
 Media defects are identified and recorded on the disc during the
 manufacturing process. This defect map is used during formatting
 and enables the drive to bypass these defects. During the formatting
 operation, the controller uses sector-slip technique to reassign
 defective sectors.

 Sector-slip allows any sector with a defect to be mapped and
 bypassed. The next contiguous sector is given that sector address.
 The ST251N/ST277N and ST296N support three variations of the format
 command:

  - Format using a combined list of previously defined defects
    (manufactires's list plus user-defined list)

  - Format with previously defined list plus additional user-
    defined defects

  - Format with manufacturer's list only (removes all user-defined
    defects)


 Access Time Definition and Timing
 ---------------------------------
 Access time is a true statistical average (at least 5,000 measure-
 ments) of the time to execute the seek, less overhead.
 Overhead is measured by issuing a no-motion seek from the highest
 Logical Block Address (LBA).
 All measurements assume a block size of 512 bytes, nominal voltages,
 25*C ambient temperature and sea level.
 Track-to-track access time is the average of all possible single-
 track seeks in both directions. Average access time is measured by
 executing seek in both directions between random cylinders or Logi-
 cal Block Addresses (LBA). Full-stroke access time is one-half the
 time needed to seek from LBA zero to the maximum LBA and back to LBA
 zero.
                                          |        |ST251N-1|
                                          |ST251N-0|ST277N-1|
                                          |ST277N-0|ST296N  |
        ----------------------------------+--------+--------+
        Track-to-Track         msec.      |   8    |   8    |
                       Average msec. typ. |  38    |  28    |
                       Average msec. max. |  40    |  30    |
        Full-Stroke            msec. typ. |  90    |  70    |
                               msec. max. |  95    |  75    |
        Latency                msec. avg. |   8.33 |   8.33 |
        ----------------------------------+--------+--------+


 DC Power Specifications
 -----------------------
 Power may be applied or removed in any sequence without loss of data
 or damage to the drive.


 SCSI bus drivers/receivers
 --------------------------
 The drives use open collector drivers. All signals are terminated
 with 220  to +5 VDC (nominal) and 330  to ground.

 For these measurements, SCSI bus termination is assumed to be
 external to the drive. A typical drive is supplied with the resistor
 termination packs installed.

   Signals driven by the drive have the following output
   characteristics, when measured at the drive connector:

   Signal true:               0.0 VDC to 0.4 VDC
   Maximum total input load:  48 mAmps (sinking) @ 0.5 VDC
   Signal false:              2.5 VDC to 5.25 VDC


   Signals received by the drive have the following input
   characteristics, when measured at the drive connector:

   Signal true:               0.0 VDC to 0.8 VDC
   Maximum total input load:  -0.4 mAmps @ 0.4 VDC
   Signal false:              0.2 VDC to 5.25 VDC
   Minimum Input Hysteresis:  0.2 VDC


 UL/CSA Certification
 --------------------
 This product is listed in accordance with UL 478 and CSA C22.2
 (0-M1982), and meets all applicable sections of IEC 380 and VDE 0806/
 08.81, as tested by TUV-Rheinland, North America.



**********************************************************************
                      G   E   N   E   R   A   L
**********************************************************************
SEAGATE   SUPPORT SERVICES

 Seagate Technology
 ------------------
 Technical Support Services
 If you need assistance installing your drive, consult your dealer.
 Dealers are familiar with their unique system configurations and can
 help you with system conflicts and other technical issues. If you
 need additional assistance with your Seagate(r) drive or other
 Seagate products, use one of the Seagate technical support services
 listed below.

 SeaFONE at 1-800-SEAGATE (1-800-732-4283)
 Seagate's 800 number allows toll-free access to automated self-help
 services, providing answers to commonly asked questions,
 troubleshooting tips and specifications for disc drives and tape
 drives. This service is available 24 hours daily and requires a
 touch-tone phone. If you need to speak to a technical support
 engineer, dial this number and listen to the options for technical
 support. (International callers can also reach this automated
 self-help service by dialing 408-456-4496).


 Seagate Technology online services
 Using a modem, you can obtain troubleshooting tips, free utility
 programs, drive specifications and jumper settings for Seagate's
 entire product line. You can also download software for installing
 and analyzing your drive.

 SeaNET
 You can obtain technical information on Seagate drives, Seagate
 software and much more over the Internet from Seagate's World Wide
 Web home page (http://www.seagate.com) or Seagate's ftp server
 (ftp://ftp.seagate.com).

 You may also send E-mail with your questions to DiscSupport@
 Seagate.com or TapeSupport@Seagate.com.


 SeaBOARD
 SeaBOARD is a computer bulletin board system (BBS) that contains
 information about Seagate's disc and tape drive products and is
 available 24 hours daily. Set your communications software to eight
 data bits, no parity and one stop bit (8-N-1). SeaBOARD phone numbers
 are listed in the following table.

 BBS Location           Modem number
 United States      Disc: 408-434-1080; Tape: 408-456-4415
 England            44-1628-478011
 France                         33 1-48 25 35 95
 Germany            49-89-140-9331
 Singapore          65-292-6973
 Thailand           662-531-8111
 Australia          61-2-9756-2359
 Taiwan             886-2-719-6075

 Seagate CompuServe forum
 Online technical support for Seagate products is available on
 CompuServe. To access our technical support forum, type go seagate.
 This forum provides information similar to that found on SeaBOARD.
 In addition, you can type questions or browse through previous
 questions and answers on the forum messages.

 Seagate Technology FAX services
 SeaFAX
 You can use a touch-tone telephone to access Seagate's automated FAX
 system to receive technical support information by return FAX. This
 service is available 24 hours daily.
 Location               Telephone number
 United States          1-800-SEAGATE or 408-456-4496
 England                44-1628-894084
 Australia              61-2-9756-5170

 Seagate technical support FAX
 You can FAX questions or comments to technical support specialists 24
 hours daily. Responses are sent during business hours.
 Location               FAX number
 United States          408-944-9120
 England                        44-1628-890660
 France                 33 1-46 04 42 50
 Germany                        49-89-1430-5100
 Australia              61-2-9725-4052
 Singapore              65-293-4722
 Hong Kong              852-2368 7173
 Taiwan                 886-2-715-2923
 Korea                          82-2-556-7294/4251


 Seagate technical support
 You can talk to a technical support specialist during business hours
 Monday through Friday for one-on-one technical help.  Before calling,
 note your system configuration and drive model number (STxxxx). There
 are several technical support phone numbers available for various
 Seagate products.

 Location          Telephone  number
 United States Please dial 1-800-SEAGATE for the specific product
               telephone number.
               (6:00 A.M. to 11:15 A.M., 12:30 P.M. to 5:00 P.M.,
               Pacific time, M-F)
 England       44-1628-894083 (10:00 A.M. to 1:00 P.M., 2:00 P.M. to
               5:00 P.M., M-F)
 France        33 1-41 86 10 86 (9:30 A.M. to 12:30 P.M., 2:00
               P.M. to 5:00 P.M., M-F)
 Germany       Disc: 49-89-140-9332; (9:30 A.M. to 12:30 P.M., 2:00
               P.M. to 4:00 P.M., M-F)
               Tape: 49-89-140-9333
 Australia     61-2-9725-3366 (9:00 A.M. to 5:00 P.M., M-F)
 Singapore     65-290-3998 (9:00 A.M. to 12:00 P.M., 2:00
               P.M. to 5:00 P.M., M-F)
 Hong Kong     852-2368 9918
 Taiwan        886-2-514-2237
 Korea         82-2-556-8241


 SeaTDD 408-944-9121
 Using a telecommunications device for the deaf (TDD), you can send
 questions or comments 24 hours daily and exchange messages with a
 technical support specialist between 6:00 A.M. to 11:15 A.M. and
 12:30 P.M. to 5:00 P.M. (Pacific time) Monday through Friday.


 Customer Service Centers
 Seagate direct OEM, Distribution, System Integrator and Retail
 customers should contact your Seagate Service Representative for
 warranty information.  Other customers contact your place of
 purchase.  Seagate offers comprehensive customer support for all
 Seagate drives.  Seagate customer service centers are the only
 facilities authorized to service Seagate drives. These services are
 available worldwide.

 Location                       Telephone number                FAX number
 United States          1-800-468-3472;                 405-949-6740
 Other Americas
 (Canada & Brazil)      405-949-6706;               405-949-6738
 Mexico                         525-546-6965;                   525-546-4888
 Europe, Middle
 East & Africa          31-2065-43300;              31-2065-34320
 Asia Pacific &
 Australia              65-485-3595;                    65-485-4980
 Japan                          81-3-5462-2904;                 81-3-3462-2979


 Seagate, Seagate Technology and the Seagate logo are registered
 trademarks of Seagate Technology, Inc. SeaFAX, SeaFONE, SeaBOARD,
 SeaTDD, SeaNET, Medalist and DiscWizard are either trademarks or
 registered trademarks of Seagate Technology, Inc. or one of its
 subsidiaries. All other trademarks or registered trademarks are the
 property of their respective owners.


