










__________________________________________________ST1102A, ST1144A
________________________________________________AT Interface Drive
________________________________________________Installation Guide
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________







__________________________________________________________Seagate


Copyright Notice

Seagate , Seagate Technology and the Seagate logo are registered
trademarks of Seagate Technology, Inc.

(C)Copyright 1990 Seagate Technology, Inc.
920 Disc Drive, Scotts Valley, California 95066-4544, USA
Telephone:  408/438-6550
Publication Number:  36154-001, Rev. B

Seagate reserves the right to change, without notice, product
offerings or specirfications. This publication, and all material
contained herein, are copyrighted with all rights reserved. No part of
this publication may be copied without written permission of Seagate
Technology, Inc.

AMI is a registered trademark of American Megatrend, Inc. Award is a
registered trademark of Award Corporation.  AT is a registered
trademark of International Business Corporation.  XT is a trademark of
International Business Machines Corporation.  Phoenix is a registered
trademark of Phoenix Corporation.  Quadtel is a registered trademark
of Quadtel Corporation.



                                                                  1


Before You Begin...

This installation guide supports Seagate's ST1102A and ST1144A Drives,
ROM 5.0, RAM 5.5 or greater.

Always verify that the system power is off before attempting any
installation.

Inspect the drive, cables, mounting hardware/accessories,
documentation and packaging.  If any item is incorrect, missing or
appears damaged, contact your Distributor or Dealer immediately.

Important Handling Notes:  Improper handling during transit/shipping
accounts for many "installation" problems. Doe not attach any labels
to the drive top cover as they may obstruct the breather holes.
Always handle the drive carefully.

Observe Static-Discharge Precautions:  Keep the drive in the static-
shielded bag until you are ready to complete the installation.  Use a
grounded wrist-strap at your workstation; if unavailable, ground
yourself frequently by touching the metal chassis of the system before
handling any components.  Avoid static-inducing carpeted areas.

Shipping:  When transporting or shipping a drive or controller, a
Seagate-approved container must be used.

Keep your original box.  They are easily identified by the Seagate
Approved Package label.  Shipping a drive in a non-approved container
will void the drive warranty.

Seagate service centers may refuse receipt of components improperly
packaged or obviously damaged in transit.  Contact your Authorized
Seagate Distributor to purchase additional boxes.  Seagate recommends
shipping by an air-ride carrier experienced in handling computer
equipment.

Maintenance:  Seagate disc drives do not require any preventive
maintenance.  The head/disc assembly is sealed and does not contain
any user-serviceable components.  Tampering with the factory-seal will
void the warranty.



                                                                  2


Seagate customer service centers are the only facilities authorized to
service Seagate drives.  Seagate does not sanction any third-party
repair facilities. Any unauthorized repair or tampering with the
factory-seal will void the warranty.

Warranty:  Contact your Seagate Authorized Distributor or your Dealer
for warranty information.

End-User Technical Support:  Seagate maintains a 24-hour bulletin
board service. This facility offers up-to-date product technical
support.

Modem Number:  408/438-8771 [300-9600 HST, MNP 3/5, N-8-1]

This is a toll call.



                                                                  3



FCC Verification

This equipment has been tested with a Class B computing device and has
been found to comply with Part 15 of the FCC rules.  These limits are
designed to provide reasonable protection against harmful interference
in residential installations.  This equipment generates, uses and can
radiate radio frequency energy, and if not used in accordance with the
instructions, may cause harmful interference to radio communications.

If this equipment does cause interference to radio or television
equipment reception, which can be determined by turning the equipment
off and on, the user is encouraged to try to correct the interference
by one or more of the following measures:

*    Reorient or relocate the receiving antenna.

*    Move the equipment away from the receiver.

*    Plug the equipment into an outlet on a circuit different from
     that to which the receiver is powered.

If necessary, the user should consult the dealer or an experienced
radio/television technician for additional suggestions.

Caution:  Any changes or modifications to the equipment by the user
not expressly approved by the grantee or manufacturer could void the
user's authority to operate such equipment.

Note: This digital apparatus does not exceed the Class B limits for
radio noise emissions from digital apparatus as set out in the Radio
Interference regulations of the Canadian Department of Communications.




                                                                  4



1.0  Drive Capacity and Geometry


1.1  ST1102A  Formatted Capacity

The following specifications are maximum logical numbers.  Available
capcity depends on the drive type geometry supported by your system
BIOS.


Guaranteed Megabytes:         89.1

Guaranteed Sectors:         174,080

Sectors per Cylinder:        255

Bytes per Sector:            512

Bytes per Track:           8,704

Bytes per Cylinder:       130,560


1.1.1 ST1102A Translation (Default) Drive Organization

Maximum logical drive geometry numbers are listed below.  These num-
bers can vary drive type, as long as they do not exceed the maximums
specified and the following product:

(Sectors/Track) (Cylinders) (Read/Write Heads) is less than or equal
to the maximum guaranteed sectors.


                              Default

Sectors per Track:            17 max

Cylinders:                  1,024 max

Read/Write Heads:             10 max



                                                                  5



1.2 ST1144A Formatted Capacity

The following specifications are maximum logical numbers.  Available
capacity depends on the drive type geometry supported by your system
BIOS.


Guaranteed Megabytes:         130.7

Guaranteed Sectors:          255,255

Sectors per Cylinder:          255

Bytes Per Sector:              512

Bytes per Track:              8,704

Bytes per Cylinder:          130,560


1.2.1  ST1144A  Translation (Logical) Drive Organization

Maximum logical drive geometry numbers are listed below.  These
numbers can vary for drive type, as long as they do not exceed the
maximums specified and the following product:

(Sectors/Track) (Cylinders) (Read/Write Heads) is less than or equal
to the maximum guaranteed sectors.


                              Default        Other

Sectors per Track:            17 max        17 max

Cylinders:                  1,001 max     1,024 max

Read/Write Heads:               15            14




                                                                  6



2.0  Drive Setup and Installation

Important Note:  All ST412 interface drive and controllers must be
removed from the system.


2.1  Master/Slave Selection

A master/slave relationship must be established between drives on the
AT bus.

Drive 1 is configured as the master and drive 2 is designated as the
slave.  The Master jumper (pins 3-4) and Slave Present jumper (pins
5-6) are noted in Figure 1 on page 8.

                       |--------------------|------------------------|
                       |    Master Jumper   |   Slave Present Jumper |                                                                                                       |
|----------------------|--------------------|------------------------|
| Single Drive System  |    Install Jumper  |     Remove Jumper      |
|----------------------|--------------------|------------------------|
| Drive 1 in a 2-Drive |    Install Jumper  |     Install Jumper     |
|      System          |                    |                        |
|----------------------|--------------------|------------------------|
| Drive 2 in a 2-Drive |    Remove Jumper   |     Remove Jumper      |
|      System          |                    |                        |
|----------------------|--------------------|------------------------|


2.2  Remote LED

When pins 9-10 at the User Configuration Jumper are shorted, the drive
will indicate activity to the host via the AT interface.


2.3  Drive Mounting and Cabling

The drive may be mounted horizontally with the PC board down or on
either side-edge. Mounting vertically, front panel up or down is
prohibited.  Required for mounting:  4, 6-32 UNC-2B X 0.150 screws.

Maximum cable length:  18-inches



                                                                  7



2.4 AT Host Adapter Support

Seagate offers two AT Host Adapters.  They are both half-slot boards,
which provide a 40-pin AT interface connector for systems lacking an
AT interface drive connector on the system motherboard.

The ST07A/ST08A support two AT interface drives.  They provide address
decoding for hard drive I/O and buffering of signals between the host
and the hard drive.

The ST08A supports up to two floppy diskette drives:

*    5.25-inch, 360 Kbyte/1.2 Mbyte

*    3.5-inch, 720 Kbyte/1.44 Mbyte

An auxiliary DC power connector is provided on both boards.



                                                                  8


Figure 1:  ST1102A/ST1144A AT Interface Drive


ST-1144A

     PWA
                          ....................    /\
                           ....................      O O O O 
       1 o o 2  Ŀ        Cable Connector   5GG12
       3 o o 4  Ŀ 
       5 o o 6  Ŀ  
       7 o o 8  Ŀ   
       9 o o 10                                    1=closed 0=open
                     Life-Test (Factory use)
                    Master on (Slave off)   1  1  0
                   Slave Present   0  1  0
                  Reserved
                 Remote LED                  S  M  S
                                                        i  a  l
                                                        n  s  a
                                                        g  t  v
                                                        l  e  e
                                                        e  r


Important Note:  The Life test jumper is used during the manufacturing
process and is not recommended for field use.



                                                                  9


3.0 Drive Partitioning and Formatting


*    Required:  DOS 3.3 or greater

*    The ST1102A and ST1144A are low-level formatted at the factory.
     Do not low-level format.  Doing so will delete important factory-
     written defect information.

*    Run FDISK for drive partitioning and then high-level format with
     the DOS FORMAT command.

*    Be sure to transfer the DOS systems files, if a bootable drive is
     required.  Consult your system DOS manual for running FDISK and
     FORMAT.


3.1  Supported System BIOS and Drive Types (Installation Guide Errata)

The ST1144A is an AT Interface compatible drive.  The following BIOS
manufacturers have indicated that the listed BIOS revision levels are
fully AT Interface compatible.

Earlier BIOS revisions may provide partial AT Interface support.  If
compatibility problems occur, please contact your system manufacturer.



                                                                  10


                                                         ST1144A
|--------------------------------------------------------------------|
|  BIOS Mfg.   |           Version                    |  Drive Types |
|--------------|--------------------------------------|--------------|
|    AMI       |         4/9/90 or later              | 9, 47, 45    |
|--------------|--------------------------------------|--------------|
|   Award      |         3.04 or higher               |     9, 41    |
|--------------|--------------------------------------|--------------|
|   Quadtel    |     Single Drive:  Any Version       |     9        |
|              |                                      |              |
|              |     Dual Drive:  3.04 or higher      |              |
|--------------|--------------------------------------|--------------|
|  Phoenix     |  ROM BIOS Plus 286 3.10 or higher    |     9, 41    |
|              |                                      |              |
|              |  ROM BIOS Plus 386 1.10 or higher    |              |
|--------------|--------------------------------------|--------------|
| Phoenix BIOS |          1.00 higher                 |     9, 41    |
|--------------|--------------------------------------|--------------|

ECC Bytes:  The ST1144A uses 4 bytes of ECC with Read/Write Long
Commands.  Based on drive type, some BIOS look for 7 bytes of ECC. If
the BIOS expects 7 bytes, some drive diagnostics will return false
failures (typically timeout errors).

AT Interface Cable Length:  18 inches max. (0.45m)



Errata to Install Guide 36154-001, Rev. B



                                                                  11


3.1.1  Drive Type Geometry

Drive types are selected and entered in the system CMOS during setup.
Match your drive type to one tabulated below:

|------------|------------|--------|------------------|--------------|
| Drive Type |  Cylinders |   R/W  |   Sectors/Track  |    Formatted |
|            |            |  Heads |                  |     MBytes   |
|------------|------------|--------|------------------|--------------|
|    33      |   1,024    |   10   |        17        |      89.1    |
|------------|------------|--------|------------------|--------------|
|    35      |   1,024    |   9    |        17        |      80.2    |
|------------|------------|--------|------------------|--------------|
|    40      |   1,024    |   9    |        17        |      80.2    |
|------------|------------|--------|------------------|--------------|
|    9       |    900     |  15    |        17        |     117.5    |
|------------|------------|--------|------------------|--------------|
|    41      |    917     |  15    |        17        |     119.7    |
|------------|------------|--------|------------------|--------------|
|    47      |   1,024    |  14    |        17        |     124.7    |
|------------|------------|--------|------------------|--------------|
|    45      |    917     |  15    |        17        |     119.7    |
|------------|------------|--------|------------------|--------------|

If you have a system BIOS which offers a "user-defined" drive type,
select from the following drive configurations:

|------------|------------|--------|------------------|--------------|
|  Drive     |  Cylinders |  R/W   |   Sectors/Track  |    Formatted |
|            |            | Heads  |                  |     MBytes   |
|------------|------------|--------|------------------|--------------|
|  ST1102A   |   1,024    |  10    |        17        |      89.1    |
|------------|------------|--------|------------------|--------------|
|  ST1144A   |   1,024    |  14    |        17        |     124.7    |
|------------|------------|--------|------------------|--------------|
|  ST1144A   |   1,001    |  15    |        17        |     130.7    |
|------------|------------|--------|------------------|--------------|

Note:  Formatted megabytes are calculated using one megabyte equals
1,000,000 bytes.


Seagate Technology, Inc.
920 Disc Drive, Scotts Valley, California 95066-4544, USA

Publication Number:  36154-001, Rev. B
