---------------------------------------------------------------------------
T H I S   I S   A   D O C U M E N T   I N   A S C I I - F O R M A T   ! ! !
---------------------------------------------------------------------------
To see the document in correct way under Windows

  1. You must have installed a font with full ASCII-Character-Set
     (like TERMINAL)
  2. Use a DOS-Editor like EDIT from original DOS-Version.
     EDIT filename.txt
  3. Switch to DOS-Box and type in
     TYPE filename.txt | MORE
  4. Switch to DOS-Box and print the file
     COPY filename.txt LPT1
     TYPE filename.txt > LPT1
---------------------------------------------------------------------------
T H I S   I S   A   D O C U M E N T   I N   A S C I I - F O R M A T   ! ! !
---------------------------------------------------------------------------



******************************************************************************
P C - D I S K     The Harddisk Information Database
DCI AG, Germany                      www.pc-disk.de
******************************************************************************

S T 1 3 8 - 1    SEAGATE        
NO MORE PRODUCED                                      Native³  Translation 
                                                      ÄÄÄÄÄÄÅÄÄÄÄÄÂÄÄÄÄÄÂÄÄÄÄÄ
Form                 3.5"/HH               Cylinders     615³     ³     ³     
Capacity form/unform    32/   38 MB        Heads           6³     ³     ³     
Seek time í / track  28.0/ 8.0 ms          Sector/track   17³     ³     ³     
Controller           MFM / ST412           Precompensation 65535
Cache/Buffer               KB              Landing Zone         
Data transfer rate    0.625 MB/S int       Bytes/Sector      512
                      0.625 MB/S ext      
Recording method     MFM                            operating  ³ non-operating
                                                  ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
Supply voltage     5/12 V       Temperature øC        10ö50    ³    -40ö60
Power: sleep              W     Humidity     %         8ö80    ³      5ö90
       standby            W     Altitude    km    -0.305ö 3.050³ -0.305ö 9.150
       idle               W     Shock        g        10       ³     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 
P C - D I S K     The Harddisk Information Database
DCI AG, Germany                      www.pc-disk.de
**********************************************************************
                        L   A   Y   O   U   T
**********************************************************************
SEAGATE  ST124/125/138/138R/157R  PRODUCT MANUAL 36045-006, REV.F

  ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿             
  ³                                             1ÚÄ¿    ³²² DATA      
  ³                         ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄį ³ ³J7  ³²² Connector 
  ³                         ³       Configuration³ ³    ³²² 20-pin    
  ³          alternate      ³       Jumper block ÀÄÙ    ³²² J2        
  ³          Position   1ÄÄÄÄÄÄÄ¿                ÚÄ¿    ³             
  ³          of J7      ÀÄÄÄÄÄÄÄÙ     Termination³ ³    ³²²           
  ³                                   Resistor   ³ ³    ³²²           
  ³                                   Pack       ÀÄÙ1   ³²²           
  ³                                                     ³²²           
  ³                                                     ³²² Connector 
  ³                                                     ³²² 34-pin    
  ³                                                     ³²² J1        
  ³                                                     ³²²           
  ³                                                     ³             
  ³                                                     ³ÛÛ           
  ³                                                     ³ÛÛ Power J3  
  ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ             
  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.  


P C - D I S K     The Harddisk Information Database
DCI AG, Germany                      www.pc-disk.de
**********************************************************************
                      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
 -----------------
     ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄ¿
     ³Drive Select ³ 9-10  ³ 11-12 ³13-14  ³15-16  ³
     ³ÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄ´
     ³Drive 4      ³ CLOSED³ OPEN  ³ OPEN  ³ OPEN  ³
     ³Drive 3      ³ OPEN  ³ CLOSED³ OPEN  ³ OPEN  ³
     ³Drive 2      ³ OPEN  ³ OPEN  ³ CLOSED³ OPEN  ³
     ³Drive 1      ³ OPEN  ³ OPEN  ³ OPEN  ³ CLOSED³
     ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÙ

 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
 -------------------------------------------
      ÚÄÄÄÄÄÄÄÄÄÄÄÄ¿   pin 1    +12 VDC
      ³ 1  2  3  4 ³   pin 2    +12 Volts Return
      ÀÄÄÄÄÄÄÄÄÄÄÄÄÙ   pin 3    + 5 Volts Return
                       pin 4    + 5 VDC


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**********************************************************************
                      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
   ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿   ÚÄÄ¿             ÚÄÄ¿ ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿
   ³                 ³   ³  ÃÄÄÄÄÄ¿ ÚÄÄÄÄÄ´  ³ ³                  ³ x
   ³                 ³   ³  ³     ³ ³     ³  ³ xÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ¿x
 ÚÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄ¿ ³  ³     ³ ³     ³  ³ ³³x              x³³
 ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ³  ³     ³ ³     ³  ³ ³³  x          x  ³³
                         ³  ³     ³ ³     ³  ³ ³³    x      x    ³³
      x           x      ³  ³     ³ ³     ³  ³ ³³      x  x      ³³
 ÚÄÄÄÄÄÄxÄÄÄÄÄÄxÄÄÄÄÄÄÄ¿ ³  ÃÄÄÄÄÄÙ ÀÄÄÄÄÄ´  ³ ³³       xx       ³³
 ÀÄÂÄÄÄÄÄÄxÄÄxÄÄÄÄÄÄÄÂÄÙ ÀÄÄÙ             ÀÄÄÙ ³³     x    x     ³³
   ³       xx        ³                         ³³   x        x   ³³
   ³     x    x      ³                         ³³ x            x ³³
   ÀÄÄÄxÄÄÄÄÄÄÄÄxÄÄÄÄÙ                         ³x                x³
     x            x                           xÀÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÙx
      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 orienÄ
 tation.
 The drive should not be tilted front or back, in any position, by
 more than 5ø. 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
 20ê resistive load on the +12 V line and an equivalent 8ê 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,
 25øC ambient temperature, sea level and spindle rotating.
 Voltage tolerance (incl. ripple): ñ5%


 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.


P C - D I S K     The Harddisk Information Database
DCI AG, Germany                      www.pc-disk.de
**********************************************************************
                      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 æsec., nominal power, sea level and 25øC 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.


                                          ³ ST124  ³ ST125-0³ ST125-1³
                                          ³        ³ ST138-0³ ST138-1³
                                          ³        ³ST138R-0³ST138R-1³
                                          ³        ³ST157R-0³ST157R-1³
        ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄ´
        Track-to-Track         msec. typ. ³  12    ³   8    ³     8  ³
                               msec. max. ³  15    ³  10    ³    10  ³
                       Average msec. typ. ³  38    ³  38    ³    28  ³
                       Average msec. max. ³  40    ³  40    ³    30  ³
        Full-Stroke            msec. typ. ³  90    ³  90    ³    70  ³
                               msec. max. ³  95    ³  95    ³    70  ³
        Latency                msec. avg. ³   8.33 ³   8.33 ³    8.33³
        ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÙ


 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.


P C - D I S K     The Harddisk Information Database
DCI AG, Germany                      www.pc-disk.de
**********************************************************************
                      G   E   N   E   R   A   L
**********************************************************************
SEAGATE   ST412 MFM/RLL

  	ST412 Interface (MFM and RLL)
 ===================================================================
 ST412 Interface (MFM and RLL) ST-506 was predecessor without buffered
 seek
 2 Cables: 1 each 34-pin Command Cable and 1 each 20-pin Data Cable
 -------------------------------------------------------------------

 Command Cable Description

 J1 (34-pin Command) Host/Drive Pin Assignments

      GROUND RTN     SIGNAL PIN     SIGNAL
         PIN
 _____________________________________________________

                                                 3
         1              2          -HEAD SELECT 2

                                                 2
         3              4          -HEAD SELECT 2

         5              6          -WRITE GATE

         7              8*         -SEEK COMPLETE

         9             10*         -TRACK 0

        11             12*         -WRITE FAULT
                                                 0
        13             14          -HEAD SELECT 2

        15             16          -RESERVED
                                                 1
        17             18          -HEAD SELECT 2


        19             20*         -INDEX

        21             22*         -READY

        23             24          -STEP

        25 (29)**      26 (28)     -DRIVE SELECT 1 (2)

        27 (27)        28 (26)     -DRIVE SELECT 2 (1)

        29 (25)        30          -DRIVE SELECT 3

        31             32          -DRIVE SELECT 4

        33             34          -DIRECTION IN

     * STATUS ENABLED WITH DRIVE SELECT
    ** TWISTED CABLE IN PARENTHESES



 J2 (20-pin Data) HOST/DRIVE PIN ASSIGNMENTS

     GROUND RTN     SIGNAL PIN     SIGNAL NAME
        PIN
 _____________________________________________________________

         2              1          -DRIVE SELECTED

         4              3          RESERVED

         6              5          RESERVED

         8              7          RESERVED

        10              9          RESERVED

        12             11          GROUND

                       13          +MFM (RLL) WRITE DATA


                       14          -MFM (RLL) WRITE DATA

        16             15          GROUND

                       17          +MFM (RLL) READ DATA

                       18          -MFM (RLL) READ DATA

        20             19          GROUND


 Seagate Technology Desk Reference July 17 2000