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Hard Drive: SEAGATE: ST138R-0 33MB 3.5"/HH RLL ST412

S T 1 3 8 R - 0    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
Form                 3.5"/HH               Cylinders     615|     |     |
Capacity form/unform    33/   38 MB        Heads           4|     |     |
Seek time   / track  38.0/ 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        40
       spin-up            W     ECC        Bit   -
                                MTBF         h     150000
                                Warranty Month
Lift/Lock/Park     YES          Certificates     CSA,FCC,IEC435,TUV,UL478,VDE 


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.



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

  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

 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


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-
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

 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

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

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%

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.

When transporting or shipping a drive, a Seagate-approved container

Drive configuration
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.

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.

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-
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-

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-

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.

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.


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.

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

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

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

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

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.



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.

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

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

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
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.

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