





                     Installing The ST11R Controller
                        With A Seagate Disc Drive

                           I. Introduction

 Seagate reserves the right to change, without notice, the specifications
 or other information contained in this file.

 The  ST11R  provides  an  interface  between  the IBM PC XT* (or compatible
 system) and up to two of the listed Seagate ST412  Run Length  Limited (RLL
 2,7) drives.

 *IBM PC XT is a registered trademark of International Business Machines
 Corporation.


 The ST11R uses RLL encoding at 7.5 megabits/sec. and is intended for
 use with drives certified for RLL. Seagate RLL drive models have an
 "R" suffix.

 Do not use the ST11R with Seagate drives designed for MFM recording at
 5.0 megabits/sec.(no "R" suffix). Running this combination will void the
 warranty on the drive.


 Drives supported by the ST11R controller.

 Drive          Formatted MB        Cylinders      R/W  Heads

 ST138R            32.7                615            4
 ST157R            49.1                615            6
 ST225R            21.0                667            2
 ST238R*           32.7                615            4
 ST250R            40.0                667            4
 ST277R            65.5                820            6
 ST4144R          122.7               1,024           9

 *earlier versions of the ST238R did not have the "R" suffix but are RLL
 compatible.


 Before attempting any installation, read through these instructions and
 verify that the system is powered-down.

 Once installed, the controller's onboard software will assist you with
 the help screens during the required formatting operation.

 -If your drive has more than 32 formatted megabytes, or if you want to
 create multiple logical drives, you must install device driver software.
 See Part III.

 Note: This device driver utility is only shipped with drives having greater
 than 32 formatted megabytes to Seagate's direct customers requesting it. If
 you did  not receive  the device  driver software with your greater than 32





 megabyte drive, contact your dealer or distributor.






               II. Controller/Drive Installation

 1. Remove the top cover from the system. Retain the screws.

 2. Configuring the ST11R:

 -Remove the controller from the protective covering and pull all the
 conductive rubber strips from between the connector pins.

 -The BIOS PROM address jumper (four pins located in the middle of the
 ST11R), is used to select the desired address.  Adding  jumpers changes the
 address. (Locations A and B are the two pins toward the front of the system
 and D and C are the two pins toward the back of the system).

 When installing the ST11R in a system that does not contain any other
 hard disc controllers, all jumpers should be removed from the BIOS PROM
 address jumper. The ST11R is shipped with the correct configuration for
 one hard disc controller.



 When installing the ST11R in a system containing a Seagate ST01 Host
 Adapter, the ST11R must be jumpered at a lower BIOS address than the
 STO1.

 When installing the ST11R in a system already containing a hard disc
 controller, the ST11R must be jumpered at a higher BIOS address than the
 other controller. If you are not sure of the other controller's address,
 try one of the two higher addresses for the ST11R (i.e. D8000h or
 E0000h).


 Configuration         BIOS address      Port Address

 No pins shorted         C8000h          320h - 323h
 (factory setting)

 Pins A-B Shorted:       D0000h          324h - 327h
 Pins C-D Shorted:       D8000h          328h - 32Bh

 Pins A-B & C-D          E0000h          32Ch - 32Fh
 Shorted:


                III. Configure the Drive:

 Examine the cable which connects the controller to the J1 connector on





 the drive. In many cases the cable will have connectors at both ends and
 a third connector approximately 6 inches from one end. The end with two
 connectors is connected to the drive. Check to see if the ribbon cable
 is split with a group of 5 wires twisted between the two connectors at the
 drive end.

  "C" Drive Configuration:

 - If you have a twisted cable (as defined above), configure the drive as
 drive select 2.

 - If you have an untwisted cable, configure the drive as drive select 1.

 Note: Drive select 1 is selected by shorting the 2 pins closest to
 where the 20 pin connector plugs into the drive. Drive select 2 is one
 set of pins over from the Drive select 1 position.

  "D" Drive Configuration:

 - if you are connecting a second hard disc to the ST11R, configure the
 drive as drive select 2.


 - If you are installing a single drive, the resistor pack must remain
 installed. If you are installing two hard disc drives, remove the
 resistor termination pack from the drive that is attached to the middle
 connector on the J1 cable. When reinstalling a resistor pack, note that
 pin-1 on the pack is denoted by a dot or numeral one. A square pad on
 the disc drive board indicates pin-1 at the socket.

 - Verify that there is a jumper installed at J8 position 7 on the drive.
 There should be only 2 jumpers installed at J8.

 4. Attach the Cables:

 Note that at all connections, pin-1 on the controller corresponds to pin-1
 on the drive. Some cables have a contrasting-color stripe on one edge to
 indicate pin-1.



 -Connect the J1 connector on the "C" drive to the connector at the end
 of the cable. Connect the J1 connector on the "D" drive (if present) to
 the middle connector on your cable. (Be sure  to remove  all the conductive
 rubber strips from between the connector pins even if that connector is not
 being used.

 -Connect the 20-pin connector on Drive "C" to the J2 connector on the
 ST11R. Connect the 20-pin connector on drive "D" (if present) to J3 on the
 ST11R.


 5. Install the controller into a vacant slot on the system motherboard.







 6. Mount the Drive:

 -Install the drive in the left bay, if possible, as the power supply may
 interfere with the routing of the cables. For ease of  installation, attach
 J1, J2  and the  power cable before you slide the drive completely back and
 into position.

 -Minimum requirements for mounting: 4. 6-32 UNC-2B x 0.31 (5/16) inch
 screws. Tighten the screws down evenly to 8 +/-.8 inch-lbs. Overtightening
 may cause drive damage.

 7. Verify that all connections are correct and replace the system cover.
 Go to Part IV for the required formatting operation.



                 IV. Formatting A Drive With The ST11R

 To format a new hard disc, or reformat a drive that was previously
 formatted, follow this procedure.

 You will need:

 -The DOS* diskettes and documentation (use the same version of DOS
 throughout the formatting operation).

 *DOS is a registered trademark of Microsoft Corporation.

 -The defect list that was shipped with the drive. Some drives are
 shipped with the defect list fixed to the drive top cover.

 1. Load a DOS bootable diskette in Drive A and power-on the system.

 2. Once the boot procedure is completed, load the DOS diskette that
 contains the DEBUG.COM program (usually found on the "DOS Supplemental
 Programs" diskette) and type DEBUG followed by return at the A> prompt.

 3. When DEBUG responds with the "-" prompt, type g=c800:5 followed by
 return.

    Further instructions will appear on your screen.

    Note: If you change the BIOS address from the default
    setting (see Controller/Drive Installation) you will need
    to type a different value in place of C800 (i.e g=D000:5)

 4. After initialization is complete you must partition and format your
 drive.  See your DOS manual for instructions  on the FDISK and FORMAT
 commands which will perform these functions.









                V. Installing Device Driver Software

 1. Load the DOS diskette in Drive A and power-on the system.

 2. At the "A>" prompt, load the Disk Manager* diskette in drive A and
 type DM followed by return.

 *Disk Manager is a registered trademark of Ontrack Computer Systems, Inc.

    Follow the instructions on the screen. Help is available
    by pressing the F1 function key. Additional help is available
    in the DM.REF file on your Disk Manager diskette.






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