previous page: Hard Drive: SEAGATE: ST224N 21MB 5.25"/HH   SCSI1 SE
page up: Hard Drive Specs from SEAGATE
next page: Hard Drive: SEAGATE: ST225N 21MB 5.25"/HH   SCSI1 SE

Hard Drive: SEAGATE: ST225 21MB 5.25"/HH MFM ST412

S T 2 2 5    SEAGATE
NO MORE PRODUCED                                      Native|  Translation
Form                 5.25"/HH              Cylinders     615|     |     |
Capacity form/unform    21/   26 MB        Heads           4|     |     |
Seek time   / track  65.0/20.0 ms          Sector/track   17|     |     |
Controller           MFM / ST412           Precompensation   300
Cache/Buffer               KB              Landing Zone      670
Data transfer rate    0.625 MB/S int       Bytes/Sector      512
                      0.625 MB/S ext
Recording method     MFM                            operating  | non-operating
Supply voltage     5/12 V       Temperature *C        10 45    |    -40 60
Power: sleep              W     Humidity     %         8 80    |      5 90
       standby       14.8 W     Altitude    km    -0.305  3.048| -0.305  9.140
       idle               W     Shock        g        10       |     40
       seek               W     Rotation   RPM      3600
       read/write    33.0 W     Acoustic   dBA
       spin-up            W     ECC        Bit
                                MTBF         h     100000
                                Warranty Month
Lift/Lock/Park     NO           Certificates     CSA,TUV,UL478,VDE            



  |                                                         |XX
  |                                                         |XX J2
  |                                                         |XX
  |                                                         |XX
  |                                                         |+-16
  |                                                         || |J7
  |                                                         || |
  |                                                         |+-2
  |                                Resistor        +-+      |XX
  |                                Termination     | |      |XX
  |                                Pack            | |      |XX
  |                                                +-+      |XX
  |                                                         |XX J1
  |                                                         |XX
  |                                                         |
  |                                                         |XX Power
  |                                                         |XX J3



Jumper setting
x = Factory setting

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

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

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

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

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

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

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

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

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



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.

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

Interface and Recording Method
The ST213 and ST225 are designed for operation with the ST412 inter-
face with MFM encoding at 5.0 MBits/sec. data transfer rate. Opera-
tion of a MFM drive with a RLL controller is not approved by SEAGATE
and will void the drive warranty.

The ST225R, ST238R and ST250R are designed for operation with the
ST412 interface with Run Length Limited (2,7) encoding at 7.5 Mbits/
sec. data transfer rate.

Radial/Daisy-Chain Mode
The Drive Select line enables the controller to select and address
the drive. Control cable interface options may use either a Daisy-
Chain or Radial configuration.

Drives can be configured in either a daisy-chain or radial mode.

The resistor pack must remain installed on the last drive in a chain.

The resistor pack must remain installed on all radially-selected

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.

Read/Write Head Park Zone
The read/write heads may be parked by issuing a seek to any cylinder
between 615-670

The read/write heads may be parked by issuing a seek to any cylinder
between 667-670

At power-on the drive will recalibrate to Track 0. If the heads are
parked while power is still applied, any step pulse will cause the
unit to 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. As a subassembly, no
Federal Communications Commission certification of the device is re-

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

 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.

A DC-unsafe condition is defined as DC voltage input to the drive
outside the specified tolerances. This condition will cause a micro-
processor reset.
This will prohibit writing, but will not directly cause a Write Fault

Handling and Static-Discharge Precautions
After unpacking, and prior to system integration, the drive may be
exposed to potential handling and ESD hazard. Do not touch the drive
connectors or board components or without observing static-discharge
preferred. Handle the drive by the frame only. Always rest the drive
on a padded surface until it is mounted in the host system.

The drive will enter the auto-truncation mode if the controller
issues an excessive number of step pulses, which would place the
read/write heads outward beyond Track 0 or inward beyond the
maximum data cylinder.

With auto-truncation active, the drive will ignore additional pulses,
take control of the actuator, and recalibrate the heads to Track 0.

 Caution: If the controller is still issuing slow-step pulses after
          the drive issues Seek Complete from auto-truncation mode,
          the drive will either reenter auto-truncation mode with
          Direction In true.

For optimum performance, precompensation is recommended for the ST213
and ST225 on tracks 300 through 614. Twelve nsec. is recommended for
both early and late bits.

Some controllers provide a default precompensation setting from cyl-
inder 128 to 256. The ST213 and ST225 will perform satisfactorily at
these settings.



Media Defects
A media defect is a read error when the data, which has been
correctly written, cannot be recovered within 16 retries.
A printout will be provided with each drive shipped listing the
location of any defect by head, cylinder, sector and byte. The defect
map will specify the number of bytes from index. For MFM this will be
based on 1.6 sec./byte. RLL encoding is based on 1.056 sec./byte.
Some drives will have the defect map fixed to the drive top cover.

 ST213  There will be no more than 11 defects total per drive.
        Cylinders 0, 1, 2 and 3 will be free of defects.

ST225 There will be no more than 21 defects total per drive.
ST225R Cylinders 0, 1, 2 and 3 will be free of defects.

 ST238R There will be no more than 33 defects total per drive.
        Cylinders 0, 1, and 2 will be free of defects.

 ST250R There will be no more than 42 defects total per drive.
        Cylinders 0, 1, and 2 will be free of defects.

Access Time Definition and Timing
Access time is defined as the time from leading edge of the last
step pulse received to Seek Complete (including setting). The step
pulse period must be 5-200 sec.

                                          | ST213  |        |
                                          | ST225  | ST225R |
                                          | ST238R | ST250R |
        Track-to-Track         msec.      |  20    |  20    |
                       Average msec. typ. |  65    |  70    |
                       Average msec. max. | 150    | 165    |
        Latency                msec. avg. |   8.33 |  10    |

Bit Jitter
Bit jitter reduction determines the relationship between the leading
edge of read data and the center of the data window.
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.

UL/CSA Listing
The 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.

MTBF 100,000 Power-on hours
PM: Not required
MTTR: 30 Minutes
Service life: 5 Years



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.

previous page: Hard Drive: SEAGATE: ST224N 21MB 5.25"/HH   SCSI1 SE
page up: Hard Drive Specs from SEAGATE
next page: Hard Drive: SEAGATE: ST225N 21MB 5.25"/HH   SCSI1 SE