
S T 1 5 7 R - 1    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
                                                      ------+-----+-----+-----
Form                 3.5"/HH               Cylinders     615|     |     |
Capacity form/unform    49/   58 MB        Heads           6|     |     |
Seek time   / track  28.0/ 8.0 ms          Sector/track   26|     |     |
Controller           RLL / ST412           Precompensation 65535
Cache/Buffer               KB              Landing Zone
Data transfer rate    0.938 MB/S int       Bytes/Sector      512
                      0.938 MB/S ext
Recording method     RLL 2/7                        operating  | non-operating
                                                  -------------+--------------
Supply voltage     5/12 V       Temperature *C        10 50    |    -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       |     60
       seek               W     Rotation   RPM      3600
       read/write     8.0 W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h     150000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC435,TUV,UL478,VDE 

**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
SEAGATE  ST124/125/138/138R/157R  PRODUCT MANUAL 36045-006, REV.F

  +-----------------------------------------------------+
  |                                             1+-+    |XX DATA
  |                         +------------------  | |J7  |XX Connector
  |                         |       Configuration| |    |XX 20-pin
  |          alternate      |       Jumper block +-+    |XX J2
  |          Position   1-------+                +-+    |
  |          of J7      +-------+     Termination| |    |XX
  |                                   Resistor   | |    |XX
  |                                   Pack       +-+1   |XX
  |                                                     |XX
  |                                                     |XX Connector
  |                                                     |XX 34-pin
  |                                                     |XX J1
  |                                                     |XX
  |                                                     |
  |                                                     |XX
  |                                                     |XX Power J3
  +-----------------------------------------------------+
  Alternate Location On Drive PC Board of the User Configuration
  Jumper. Note position of Pin 1 on both configurations. Jumper blocks
  in either position are identical in function.



**********************************************************************
                      J   U   M   P   E   R   S
**********************************************************************
SEAGATE  ST125/ST138/ST138R/ST157R  PRODUCT MANUAL 36045-006, REV.F

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

 J7   Radial/Daisy-Chain Mode
 ----------------------------
    1- 2  CLOSED  Radial mode
    1- 2  OPEN    Daisy-Chain mode

 This drive can be configured in either Radial or Daisy-Chain mode.
 Radially-selected drives are allways selected. The Radial option is
 enabled by shorting pins 1-2 at the User Configuration block. The
 resistor termination pack must remain installed on any radially-
 selected drive. In a Daisy-Chain, the last drive on the chain must
 have the resistor pack installed.

 NOTE: Termination resistors on the ST124 are NOT REMOVABLE!


 J7   Not used
 -------------
    3- 4  OPEN    Not used


 J7   Write Fault Latch
 ----------------------
 Write Fault is indicated by a latched signal on the interface. It can
 be cleared by deselecting the drive or with a power-off/on cycle.
 When the Radial jumper (pin 1-2 shorted at user configuration jumper
 block) is used, the drive is continuously selected and requires a
 power-on/off cycle to clear Write-Fault.

    5- 6  OPEN    The Write Fault signal can only be cleared by a
                  power on/off cycle. Use of this option in conjunc-
                  tion with the DC-unsafe option is not recommended.

    5- 6  CLOSED  The Write Fault signal can be cleared by deselecting
                  the drive. When the drive is deselected and the
                  fault condition is corrected, the Write Fault signal
                  will be false.

 These options allow the user to configure the Write Fault reset to
 specific system requirements.


 JP1/J7  Write Fault Options
 ---------------------------
  Implementation  of the Write Fault Option (Pins not illustrated)
  is by factory order only. Jumper pins must be factory-installed.
  JP1 has three jumper pads, and is located adjacent to the 34-pin J1
  connector.

  Standard: 1 and 2 jumpered on JP1
            Write Fault will be cleared when Write Gate is false.
            A Write Fault will only occur when Write Gate is true.
  Latched:  2 and 3 jumpered on JP1
            This option will maintain Write Fault true after Write
            Gate goes false and is recommended for controllers that
            do not edge-detect Write Fault. The latched option has two
            configurations which are provided at the User Configura-
            tion block, pins 5-6.


 J7   Factory test
 -----------------
    7- 8  OPEN    This is a test function used during the manufactu-
                  ring process and is not recommended for field use.
                  When shorted, the actuator will continuously seek
                  between Track 0 and the maximum data cylinder, ig-
                  noring control signals sent via the interface.


 J7   Drive select
 -----------------
     +-------------+-------+-------+-------+-------+
     |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.


 JP2  DC-Unsafe Option
 ---------------------
      Implementation of the DC-unsafe option is by factory order only.

      JP2 has two jumper pads, and when a jumper is installed, a DC-
      unsafe condition will cause a Write Fault to be sent to the
      interface.


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



**********************************************************************
                      I   N   S   T   A   L   L
**********************************************************************
SEAGATE  ST124/125/138/ST138R/ST157R  PRODUCT MANUAL 36045-006, REV.F

 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.


 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
 -------------
 When the read/write heads are positioned in the shipping zone, all
 portions of the head/slider assembly park inboard of the maximum data
 cylinder.

 ALL DRIVES EXCEPT ST124: The read/write heads automatically move to
                          the shipping zone at power-down.

 The read/write heads may be parked by issuing a seek command to any
 cylinder between 614 and 666.

 When power is applied, the heads will recalibrate to Track 0. If the
 heads are parked while power is applied, any step pulse will cause
 the unit to recalibrate to Track 0.


 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
 20  resistive load on the +12 V line and an equivalent 8  load on the
 +5 V line.


 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.
 As a subassembly, no Federal Communications Commission authorization,
 verification or certification of the drive is required.
 Seagate Technology, Inc. has tested these devices in an enclosure as
 described above to ensure that the total assembly (enclosure, disk
 drive, motherboard, power supply, etc.) does comply with the limits
 for a Class B computing device. Operation with non-certified assem-
 blies is likely to result in interference to radio and television
 reception.


 Recording Method
 ----------------
 The ST124, ST125 and ST138 drives are designed to operate with the
 ST412 interface with MFM encoding at 5.0 Mbits/sec. transfer rate.

 Caution: Operation of an MFM-certified drive with an RLL controller
          is not approved by Seagate and may void your warranty.

 The ST138R and ST157R are designed to operate with the ST412 inter-
 face with Run Length Limited (2,7) encoding at 7.5 megabits/sec.
 data transfer rate.


 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.


 DC Power specifications
 -----------------------
 Power may be applied or removed in any sequence without loss of data
 or damage to the drive, except during a write operation. Typical
 current and power specifications assume nominal voltages applied,
 25*C ambient temperature, sea level and spindle rotating.
 Voltage tolerance (incl. ripple):  5%


 Precompensation
 ---------------
 The drive family does not require precompensation


 Auto Truncation
 ---------------
 If the controller issues an exessive number of step pulses that would
 place the read/write heads outside Track 0, or inside the maximum
 track, the drive enters auto-truncation mode.


 Shipping
 --------
 When transporting or shipping a drive, a Seagate-approved container
 MUST BE USED. SHIPPING A DRIVE IN A NON-APPROVED CONTAINER WILL VOID
 THE DRIVE WARRANTY!


 Drive configuration
 -------------------
 SET DRIVE TERMINATION RESISTORS
 Daisy-Chain: 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 (phy-
 sically farthest from the controller) reauires termination. All other
 drives should not be terminated. Maximum permitted cable length,
 measured from the controller to the last drive is 30.5 cm.
 Radial: Each radially connected drive has its own control and data
 cable. This configuration is not required for PC applications.

 ATTACH CONTROL AND DATA CABLES
 On most cables a colored stripe down one side designates pin 1. This
 should be aligned with pin 1 on the drive and controller connectors.

 SET DRIVE SELECT AND CHECK CONTROL CABLE PINS
 If pins 25 through 29 on the wide control cable are twisted, then
 both drives should be set to Drive Select 2. If these pins are not
 twisted on the command cable, the boot drive should be set to Drive
 Select 1, while the second drive (if present) should be set to Drive
 Select 2. In all cases, the boot drive must be physically located at
 the end of the drive cable.


 CMOS configuration
 ------------------
 Basic information about the drive must be entered into the host
 system CMOS, so that it may properly access the drive for reading
 and writing data. The number of heads, cylinders and sectors per
 track are specific to each drive and collectively define the drive's
 geometry. CMOS configuration is system dependent and is usually
 accomplished through a utility such as SETUP.

 If the controller has an onboard BIOS, the drive type should be set
 to type zero, or the "no drive installed" option.

 If your system CMOS does not offer an exact match to the geometry
 listed, set the drive to a type which closely matches the drive geo-
 metry, BUT DOES NOT EXCEED THE HEAD AND CYLINDER COUNT SPECIFIED. A
 drive type which matches the number of heads exactly with a cylinder
 count less than or equal to the number of cylinders specified is pre-
 ferred.

 After the drive has been properly configured for the system, and the
 correct drive type has been specified to the system CMOS, the drive
 should be low-level formatted.


 Low Level Formatting
 --------------------
 After the drive has properly configured for the host system, it may
 need to be low-level formatted. The low-level format writes the
 sector boundaries and track information to the drive. This provides
 the system with head positioning and defect management information.

 You will need to boot the system to the floppy drive. Run the DEBUG
 utility provided with DOS to access the low-level format program
 present on the controller card. Refer to the controller for the spe-
 cific address needed to initiate the low-level format routine. The
 most common command to initiate this routine is: g=C800:5. Verify
 the address (C800) and the offset with your controller manual. If a
 hard-error map has been provided with the drive, make shure the
 errors are specified to the utility during the low-level format pro-
 cess.

 If the controller does not have a ROM BIOS, you need a third-party
 software package such as Ontrack's Disk Manager or IBM's Advanced
 Diagnostics for low-level formatting the drive.


 Partitioning
 ------------
 A drive can be subdivided into "partitions", which behave as indivi-
 dual drives within the system. Earlier versions of DOS have a limi-
 tation on maximum drive capacity and consequently require high capa-
 city drives to be divided into smaller partitions. For DOS users,
 each partition will be assigned a different letter, i.e., C: and D:
 for a drive with two partitions.

 Drive partitioning in DOS is done by using the FDISK utility. After
 the drive has been configured, defined in CMOS and low-level format-
 ted (if necessary), the user must boot the system to the floppy drive
 with a bootable DOS diskette. The user must then run the FDSIK util-
 ity to partition the drive. Refer to your DOS manual for instruction
 on using FDISK.

 Many UNIX based operating systems allow partitioning of the drive for
 use by DOS applications. In UNIX, drive formatting and partitioning
 are both done by a single operating system utility. Refer to your
 system documentation for instructions.


 High level formatting
 ---------------------
 High-level formatting verifies the information written by the low-
 level format and establishes drive access information used by the
 operating system.
 High-level formatting in DOS creates the File Allocation Table used
 by DOS for all drive access. The high-level format is initiated in
 DOS by the FORMAT command.
 High-level formatting in UNIX creates the I-NODE used by the system
 for file access information. In UNIX, drive formatting and partitio-
 ning are both done by a single operating system utility.



**********************************************************************
                      F   E   A   T   U   R   E  S
**********************************************************************
SEAGATE  ST124/125/138/ST138R/ST157R  PRODUCT MANUAL 36045-006, REV.F

 Media Defects
 -------------
 A media defect is a read error when the data, which has been
 correctly written, cannot be recovered within 16 retries.
 A label is fixed to the drive listing the location of any media
 defects by cylinder, head and bytes from index.

 ST124/ST125
 There will be no more than twenty-one (21) defects total per drive.
 Cylinders 0, 1, 2 and 3 are free of defects.

 ST138
 There will be no more than forty-nine (49) defects total per drive.
 Cylinders 0, 1 and 2 are free defects.

 ST138R
 There will be no more than thirty-two (32) defects total per drive.
 Cylinders 0, 1 and 2 are free of defects.

 ST157R
 There will be no more than forty-nine (49) defects total per drive.
 Cylinders 0 and 1 are free defects.


 Bit Jitter
 ----------
 Bit jitter reduction determines the relationship between the leading
 edge of read data and the center of the data window.
 The specified read error rates are based on the following bit jitter
 specifications: the data separator must provide at least -40dB of
 bit jitter reduction at 2F with an offset of less than 1.5 nsec.
 shift from the center of the data window.


 Seek Time Definition and Timing
 -------------------------------
 Seek time is defined as the time from leading egde of the first step
 pulse received to Seek Complete, including settling.
 All seek times are true statistical averages and are calculated with
 a step pulse of 10  sec., nominal power, sea level and 25*C ambient
 temperature.

 Important Note: Early ST125, ST138 and ST157 drives offered Dash-0
 and Dash-1 versions. All drives currently produced feature the Dash-1
 seek times.


                                          | ST124  | ST125-0| ST125-1|
                                          |        | ST138-0| ST138-1|
                                          |        |ST138R-0|ST138R-1|
                                          |        |ST157R-0|ST157R-1|
        ----------------------------------+--------+--------+--------+
        Track-to-Track         msec. typ. |  12    |   8    |     8  |
                               msec. max. |  15    |  10    |    10  |
                       Average msec. typ. |  38    |  38    |    28  |
                       Average msec. max. |  40    |  40    |    30  |
        Full-Stroke            msec. typ. |  90    |  90    |    70  |
                               msec. max. |  95    |  95    |    70  |
        Latency                msec. avg. |   8.33 |   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.


 UL/CSA Listing
 --------------
 The St157 drive family is listed in accordance with UL 478 and CSA
 C22.2 (0-M1982), and meets all applicable sections if 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.


