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                                         OS2.TXT
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Installation Guide for the Symbios SDMS OS/2 DRIVERS:
SYM8XX.ADD V4.11.00 and SYM_HI.ADD V4.10.00

Introduction
  Features 
  Description 
  Symbios Devices Supported
Installing Your SDMS OS/2 Driver
Driver Order in the CONFIG.SYS File
Command Line Options
Troubleshooting


*******************************  Introduction  ********************************

The OS/2 operating system version 4.0 provides an integrated platform featuring
the Presentation Manager graphical windowing interface that allows multiple
applications to be viewed at the same time. Multitasking is also supported,
enabling several different programs to run at the same time in different 
windows. Presentation Manager allows the user to switch between programs,
start other programs, and maintain files and directories. This version of
OS/2 requires an 80386 or higher microprocessor. Other hardware requirements
include a minimum of 8 Mbytes of RAM and a minimum hard disk drive size
of 90 Mbytes. SDMS 4.0 provides the necessary SCSI device drivers for OS/2.
LSI Logic recommends reviewing the OS/2 manual prior to proceeding.


* *  *  *  *  *  *  *  *  *  *  *  *  Features  *  *  *  *  *  *  *  *  *  *  *


o  Supports synchronous negotiation (including Fast SCSI/Ultra SCSI/Ultra2 SCSI) 
o  Supports wide SCSI (single-ended and differential) 
o  Supports multiple host adapters 
o  Supports disconnect/reselect 
o  Supports scatter/gather 
o  Allows tagged command queuing 
o  Supports single-ended, differential, and low-voltage differential
   termination   
o  Allows target-initiated negotiation 
o  Allows up to 8 host adapters
o  Supports NVRAM/NVS configuration storage
o  Supports alternate CHS (Cylinder Head Sector) mapping algorithm
o  Provides a command line /EXCLUDE option to block use of a specified adapter
o  Provides higher performance by requiring only one interrupt per I/O
o  Supports flexible GPIO pin definition using a table in the manufacturing
   data area of NVM


*  *  *  *  *  *  *  *  *  *  *  * Description  *  *  *  *  *  *  *  *  *  *  *

Although the Symbios SCSI controller's firmware can access the SCSI hard disk
drives attached to the computer independently, the SCSI device drivers
SYM8XX.ADD and SYM_HI.ADD act as an enhanced interface between the computer
system and the SCSI BIOS firmware. Use of the device drivers increases the
abilities of the SCSI controller firmware and fully utilizes the advancements
and improvements of Pentium-based and higher microprocessors.
 
The device drivers are also necessary to support the use of SCSI tape drives
and CD-ROM drives with an OS/2 system. The SYM8XX.ADD and SYM_HI.ADD device 
drivers are written in compliance with the IBM OS/2 ADD (Adapter Device Driver)
specification, and the device drivers work with third party applications that 
comply with the same specification.

Both the SYM8XX.ADD V4.11.00 and SYM_HI.ADD V4.10.00 drivers allow up to 8 host
adapters to be present in your system. The first 4 host adapters will be 
accessed in the order you specify using the SCSI BIOS Configuration Utility 
provided with some members of the 8XX family of host adapters. Refer to your
host adapter user's guide for information on the availability and use of the
SCSI BIOS Configuration Utility. Remaining host adapters will be accessed
based on their physical position in your system. Refer to your system
documentation for further information.


*  *  *  *  *  *  *  *  *  *  Symbios Devices Supported  *  *  *  *  *  *  *  * 
 
The SYM8XX.ADD driver supports the following devices and associated Symbios
host adapters:

SYM53C810, SYM53C810A, SYM53C810AE (SYM8100S, SYM8100ASP) 
SYM53C815 (SYM815XS, SYM8150SP) 
SYM53C825, SYM53C825A (SYM8250S, SYM8251S, SYM8251D, SYM8250ASP, 
SYM8251ASP, SYM8251AD) 
SYM53C860, SYM53C860AE (SYM8600SP) 
SYM53C875, SYM53C875E (SYM8750SP, SYM8751SP, SYM8751SPE, SYM8751D) 
SYM53C876 (SYM22801, SYM22802) 
SYM53C885 
SYM53C895 (SYM8951U, SYM8952U)
SYM53C895A (SYM8953U)

The SYM_HI.ADD driver supports the SYM53C896 device and the SYM22910 and
SYM21002 host adapters based on that device.


************************* Installing Your SDMS OS/2 Driver ********************

This section provides instructions on:

Installing SYM8XX.ADD/SYM_HI.ADD with OS/2 Already Installed
Installing SYM8XX.ADD/SYM_HI.ADD and OS/2 from a Floppy to a 
  SCSI Hard Drive
Installing SYM8XX.ADD/SYM_HI.ADD and OS/2 from a SCSI CD-ROM to a
  SCSI Hard Drive

These installation instructions are specific and accurate for the SDMS OS/2
SYM8XX.ADD V4.11.00 and SYM_HI.ADD V4.10.00 Drivers. Refer to the text file 
OS2.TXT located on the SDMS diskette for a version of these instructions 
guaranteed to match your driver.

The Symbios device driver floppy diskette contains six files for OS/2: 

1. Device drivers SYM8XX.ADD and SYM_HI.ADD, 

2. Text files SYM8XX.DDP and SYM_HI.DDP, and 

3. Executable files SYM8XXPC.EXE and SYM_HIPC.EXE. 

When the device driver installation utility under OS/2 is activated, it looks 
for all files with the DDP extension. The DDP files contain the necessary 
information to install the SCSI device driver. The EXE files contain a utility
that verifies that an appropriate adapter is present. If you do not wish to
install both device drivers, create a floppy diskette containing the 
appropriate driver, DDP file, and EXE file to use instead of the Symbios
device driver floppy diskette.

Note: If you previously installed OS2CAM.ADD (a previous version of the 
      SYM8XX.ADD driver), delete OS2CAM.ADD and the corresponding BASEDEV=
      statement in the CONFIG.SYS file after you complete the installation
      procedures. If you previously installed SYM8XX.ADD and/or SYM_HI.ADD
      in a directory other than \OS2\BOOT, move SYM8XX.ADD and/or SYM_HI.ADD
      to \OS2\BOOT, where the new versions of these drivers can replace the
      old versions. The system will continue to boot using the previous drivers
      until these steps are taken.


*  *  *   Installing SYM8XX.ADD/SYM_HI.ADD with OS/2 Already Installed  *  *  * 

1.  At the OS/2 Desktop, open the System Setup folder located within the OS/2
    System folder. Open the Install/Remove folder and then double click on the 
    Device Driver Install icon.
 
2.  Insert the floppy diskette containing the Symbios device driver(s) in the
    source drive. The system will find all DDP files on the floppy diskette and
    automatically install the corresponding drivers.

3.  To make sure that the installation was successful, open the Utilities
    folder located within the Programs folder on the OS/2 Desktop. Then double
    click on the OS/2 System Editor to start the editor. Open the CONFIG.SYS 
    file in the root directory and find the line(s): 

    BASEDEV=SYM8XX.ADD /V

    and/or

    BASEDEV=SYM_HI.ADD /V

    Then check that the appropriate drivers are in the \OS2\BOOT directory on
    the boot drive.


* Installing SYM8XX.ADD/SYM_HI.ADD and OS/2 from a Floppy to a SCSI Hard Drive * 

In this case, since OS/2 will be installed from a floppy diskette, it is not
required that the driver be present to install the operating system (as is the
case when installing from a CD-ROM). 

1. After the installation of OS/2 completes and the OS/2 Desktop builds, open
   the System Setup folder located in the OS/2 System folder. Open the 
   Install/Remove folder and then double click on the Device Driver Install
   icon.

2. Insert the floppy diskette containing the Symbios device driver(s) in the
   source drive. The system will find all DDP files on the floppy diskette and
   automatically install the corresponding drivers.

3. To make sure that the installation was successful, open the Utilities folder
   located within the Programs folder on the OS/2 Desktop. Then double click on
   the OS/2 System Editor to start the editor. Open the CONFIG.SYS file in the 
   root directory and find the line(s):

   BASEDEV=SYM8XX.ADD /V
  
   and/or
  
   BASEDEV=SYM_HI.ADD /V

   Then check that the appropriate drivers are in the \OS2\BOOT directory on 
   the boot drive.

4. Continue with the OS/2 installation process as documented in the OS/2 
   Installation Guide.


* Installing SYM8XX.ADD/SYM_HI.ADD and OS/2 from a SCSI CD-ROM to a 
  SCSI Hard Drive *

To install OS/2 from a SCSI CD-ROM attached to a Symbios host adapter, the SCSI
driver must be present in order to access the CD-ROM. 

1. Make copies of the floppy diskettes used for installation that are included
   with the CD-ROM version of OS/2.

2. Determine the appropriate driver for installation by locating the host 
   adapter to which the CD-ROM is attached in the section of this guide titled
   "Symbios Devices Supported". Then copy the indicated driver to the copy of
   Diskette 1. In order to do so, you must delete files on Diskette 1 to
   provide space. Consult the README.1ST file on the Device Driver Pak. It
   contains a list of files that may not be deleted. Follow the instructions
   provided in the README.1ST file. Once space is made available on Diskette 1,
   copy the appropriate Symbios device driver onto this diskette.
 
   When ADD drivers are deleted from Diskette 1, make certain to delete or
   remark out the corresponding BASEDEV= statement in the CONFIG.SYS file. 
   Otherwise, error messages will show up during installation.

3. Edit the CONFIG.SYS file on the copy of Diskette 1 by adding one of the
   following lines at the end of the file:

   BASEDEV=SYM8XX.ADD /V 
  
   or

   BASEDEV=SYM_HI.ADD /V

   Follow the directions in the README.1ST file for adding the following line
   to the CONFIG.SYS file:

   SET COPYFROMFLOPPY=1

   This allows the Symbios driver to be copied from the installation diskette
   to the system's boot drive.

4. Place the copy of Installation Diskette in the A: drive and reboot the 
   computer.

5. Proceed with the OS/2 installation process as documented in the OS/2
   Installation Guide.


*  *  *  *  *  *  *  *  Driver Order in the CONFIG.SYS File *  *  *  *  *  * * 

Because of the way OS/2 assigns drive letters, the order in which drivers
appear in the CONFIG.SYS file is important. The drivers must appear in the
order in which the drive letters are to be assigned. In particular:

o   OS/2 will install the BASEDEV= line at the beginning of the target
    system's CONFIG.SYS file regardless of where the line is located in that
    file on Diskette 1. You may need to rearrange the order in which drivers 
    appear in the CONFIG.SYS file for the target system. 

o   The driver for the host adapter to which the boot device is attached must 
    appear before all other BASEDEV=drivers in the CONFIG.SYS file.
 
o   If you are installing both Symbios drivers, the driver corresponding to the
    host adapter with the boot drive attached must appear first in the 
    CONFIG.SYS file. 

Refer to the OS/2 documentation to fully understand this requirement. 


*  *  *  *  *  *  *  *  *  *  * Command Line Options *  *  *  *  *  *  *  *  * 

Using the /VERBOSE Option
Using the /!DM Option
Using the /!SM Option
Using the /EXCLUDE Option
Using the /SYNCH_RATE Option
Using the /SYNCH_OFFSET Option
Using the /TIMEOUT Option
Using the /DISCONNECT Option
Using the /PARITY Option
Using the /QTAG Option
Using the /WIDTH Option

Your host adapter has a default configuration that consists of optimal values
for operation. You may decide to alter these default values if there is a
conflict between device settings or if you need to optimize system performance.
Some values may be changed using the SCSI BIOS Configuration Utility provided
with some members of the 8XX family of host adapters. Refer to your host
adapter user's guide for information on the availability and use of the SCSI
BIOS Configuration Utility. In addition, the Symbios OS/2 device drivers have
several embedded functions that can be accessed by using switches on the 
command line in the CONFIG.SYS file. 

Note: Values are applied in the following order:

o Manufacturer's settings 
o SCSI BIOS Configuration Utility changes 
o Command line options 

At any point during this process, subsequent changes in synchronous and wide 
negotiations may only decrease speed or reduce width. Any changes that attempt
to increase speed or width will be ignored.

The options available using command line switches are described below. The
SYM8XX.ADD driver is used in all examples; SYM_HI.ADD may be substituted for
SYM8XX.ADD with identical results.


*   *   * Using the /VERBOSE (or /V) Option *   *   *

This option appears on the command line by default. It enables display of a
banner, version number, and SCSI bus information during startup of the system. 

Usage: /VERBOSE

For example, to see more detailed information displayed when you boot, the line
in the CONFIG.SYS file that loads SYM8XX.ADD should look like this:

     BASEDEV=SYM8XX.ADD /VERBOSE
     
     or
     
     BASEDEV=SYM8XX.ADD /V

To disable this feature, remove this switch from the command line.


*   *   * Using the /!DM Option *   *   *

This option disables use of the IBM-supplied DASD manager (OS2DASD.DMD) for the
devices listed. The DASD manager supports direct access devices such as hard
drives.

Usage: /!DM<hba[:id]>[,<hba[:id]>]*

Where:
       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter
       for the id value. Instead, use the hba value as indicated in the 
       preceding paragraph.

       [ ] indicate optional information. 

       * indicates the pattern enclosed in the [ ] may be repeated. 

For example, to disable OS2DASD.DMD for devices on host adapter 0 at target
IDs 3 and 5, the line in the CONFIG.SYS file that loads SYM8XX.ADD should look
like this:

     BASEDEV=SYM8XX.ADD /!DM<0:3>,<0:5>
 
*   *   * Using the /!SM Option *   *   * 

This option disables use of the IBM-supplied SCSI manager (OS2SCSI.DMD) for the
devices listed. The SCSI manager supports SCSI tape drives.

Usage: /!SM<hba[:id]>[,<hba[:id]>]*

Where:
       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter
       for the id value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated. 

For example, to disable OS2SCSI.DMD for devices on host adapter 0 at target IDs
3 and 5, the line in the CONFIG.SYS file that loads SYM8XX.ADD should look like
this:

       BASEDEV=SYM8XX.ADD /!SM<0:3>,<0:5>
 
*   *   * Using the /EXCLUDE (or /X) Option *   *   *

This option disables a host adapter so that it is not seen by the Symbios OS/2
device drivers. This allows a host adapter to be ignored without physically
removing the board from the system. This may be necessary if the adapter in
question is causing a resource conflict.

Note: If you exclude the adapter to which the boot device is attached, then
      you will not be able to boot.

Usage: /EXCLUDE<chip:bus:dev/func>[,<chip:bus:dev/func>]*

Where:
       chip is a unique identifier that indicates the Symbios board type. The
       Verbose option displays a table with this value appearing in the  "CHIP"
       column.

       bus represents the PCI bus number into which the adapter is plugged. The
       Verbose option displays a table with this value appearing in the "BUS" 
       column. 

       dev/func is the number derived by combining the PCI device and function
       numbers and functions as a unique board identifier in conjunction with
       the PCI bus. The Verbose option displays a table with this hexadecimal
       value appearing in the "DEV/FUNC" column. It may contain an A, B, C, D,
       E, or F as part of its value. 

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated.

For example, to exclude a host adapter with chip type F, PCI bus number 0 
and dev/func number A0, the line in the CONFIG.SYS file that loads SYM8XX.ADD
should look like this:

       BASEDEV=SYM8XX.ADD /EXCLUDE<F:0:A0>


*   *   * Using the /SYNCH_RATE (or /SR) Option *   *   *

This option sets the maximum synchronous transfer rate (in Mbyte transfers per
second) to negotiate with a particular device. The allowable values for this
setting are 0, 5, 10, 20, and 40 Mbyte transfers per second, if the adapter
is capable of the specified speed. All host adapters in the 8XX family support
at least 10 Mbyte transfers per second; some support 20 or 40 Mbyte transfers 
per second. To turn off synchronous transfers for a particular device, specify
0 (zero). The value set by this option only defines the maximum transfer rate 
negotiated. The actual rate also depends on what the device can do. The 
default value is the fastest transfer rate that is supported by a particular
host adapter.

Note: The maximum synchronous transfer rates effectively double when the
      adapter and device permit wide transfers (See the /WIDTH option).
      For example, a synchronous transfer rate setting of 40 Mbyte transfers 
      per second will actually produce a transfer rate of 80 Mbyte transfers
      per second if the adapter and device both allow and are set to perform
      wide transfers.

Usage: /SYNCH_RATE=n<hba[:id]>[,n<hba[:id]>]*

Where:
       n = 0, 5, 10, 20, or 40. 

       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter 
       for the id value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated.

For example, to turn off synchronous transfers to ID 3 on host adapter 0, the
line in the CONFIG.SYS file that loads SYM8XX.ADD should look like this:

       BASEDEV=SYM8XX.ADD /SYNCH_RATE=0<0:3>

As another example, to set synchronous transfers to 10 Mbyte transfers per
second on all devices on host adapter 1, the line in the CONFIG.SYS file that
loads SYM8XX.ADD should look like this:

       BASEDEV=SYM8XX.ADD /SR=10<1>


*   *   * Using the /SYNCH_OFFSET (or /SO) Option *   *   *

This option sets the maximum synchronous offset to negotiate with a particular
device. The allowable values for this setting are 0 to the maximum synchronous
offset supported by the specified adapter. The SYM53C8XX controller chips 
support offsets up to 31. Refer to your host adapter user's guide for
information on the maximum offset supported by your host adapter. If 0 (zero)
is specified for the synchronous offset value, synchronous transfers are turned
off for any specified device. The value set by this option only defines the
maximum offset that is negotiated. The resulting rate also depends on the
device's capability. The default value is the maximum offset that is supported
by a particular host adapter.

Usage: /SYNCH_OFFSET=n<hba[:id]>[,n<hba[:id]>]*

Where: 
       n = 0 up to maximum synchronous offset for the adapter.
    
       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter
       for the id value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated. 
  
For example, to change the synchronous offset to 6 for ID 3 on host adapter 0,
the line in the CONFIG.SYS file that loads SYM8XX.ADD should look like this:

       BASEDEV=SYM8XX.ADD /SYNCH_OFFSET=6<0:3>


*   *   * Using the /TIMEOUT (or /T) Option *   *   *

The Symbios device drivers use a timeout mechanism to detect certain errors.
When the driver issues a command to a SCSI device, a timer is started. If the
timer expires before the command completes, the driver assumes that something
has gone wrong with the device, and takes steps to recover. The default value
for this is 10 seconds. If you set the value to be less than the system has
allocated for a particular device, your value will be ignored. To turn off the
timeout mechanism for a particular device, set the value to 0 (zero).

Usage: /TIMEOUT=n<hba[:id]>[,n<hba[:id]>]*

Where: 
       n = timeout value in seconds for device, n=0-65535 

       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of 
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter
       for the id value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information. 

       * indicates the pattern enclosed in the [ ] may be repeated.
 
For example, if you have a particularly slow device at ID 3 on host adapter 0
and you wish to extend the timeout on this device to 60 seconds, then the line
in the CONFIG.SYS file that loads SYM8XX.ADD should look like this:

       BASEDEV=SYM8XX.ADD /TIMEOUT=60<0:3>


*   *   * Using the /DISCONNECT (or /DC) Option *   *   *

SCSI devices have the ability to disconnect from the bus during an I/O
transfer. This option allows (or does not allow) a device to disconnect during
an I/O transfer. If a particular adapter has parity checking disabled, then you
must use this option to disable disconnects for all devices on that adapter 
that do not generate parity. Refer to the /PARITY option for more information.

Usage: /DISCONNECT=n<hba[:id]>[,n<hba[:id]>]*

Where:
       n = ON is the default value for all devices, which allows disconnects.
           OFF does not allow disconnects. 
           
       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of 
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter
       for the ID value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information. 

       * indicates the pattern enclosed in the [ ] may be repeated. 

For example, to disable disconnects on the device at ID 2 on host adapter 0,
then the line in the CONFIG.SYS file that loads SYM8XX.ADD should look like 
this:

       BASEDEV=SYM8XX.ADD /DISCONNECT=OFF<0:2>


*   *   * Using the /PARITY (or /P) Option *   *   *

The SYM53C8XX chips are capable of enabling or disabling the SCSI bus data
integrity checking feature known as parity. Some non-SCSI compliant devices
sold as SCSI devices do not generate parity. You can use this option to
disable parity checking. The SYM53C8XX chips always generate parity (for 
outputs), but may optionally check the parity (for inputs). 

Note: When disabling parity checking, it is necessary to disable disconnects
      for any device that does not generate parity, as the SYM53C8XX chips
      cannot disable parity checking for that device during the reselection
      phase. If a device does not generate parity and it disconnects, the
      I/O never completes as the reselection never completes. Refer to using
      the /DISCONNECT option for more information about disabling disconnects
      for a device. 

Usage: /PARITY=n<hba[,hba]*>[,n<hba[,hba]*>]*

Where: 
       n = ON is the default value for all devices, which enables parity
           checking. OFF disables parity checking. 

       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of 
       the host adapter. 

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated. 

For example, to turn off parity checking on host adapter 0, the line in the
CONFIG.SYS file that loads SYM8XX.ADD should look like this:

      BASEDEV=SYM8XX.ADD /PARITY=OFF<0>


*   *   * Using the /QTAG (or /QT) Option *   *   *

Queue tagging allows more than one outstanding command per SCSI device. Some 
non-SCSI compliant devices sold as SCSI devices do not allow queue tags, in
which case queue tagging needs to be disabled. The value given in the command
line will be the depth of the queue for queue tags for the device(s) indicated.
To disable queue tag support, a value of 0 or 1 should be given.

Usage: /QTAG=n<hba[:id]>[,n<hba[:id]>]*

Where: 
       n = the number of queue tags allowed for a device (0-256). 

       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter 
       for the id value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated. 

For example, to turn off queue tagging for ID 3 on host adapter 0, the line in
the CONFIG.SYS file that loads SYM8XX.ADD should look like this:

       BASEDEV=SYM8XX.ADD /QTAG=0<0:3>

As another example, to set the queue depth to 5 for all devices on host adapter
2, the line in the CONFIG.SYS file that loads SYM8XX.ADD should look like this:

       BASEDEV=SYM8XX.ADD /QT=5<2>


*   *   * Using the /WIDTH (or /W) Option *   *   *

Devices attached to a SCSI bus are narrow or wide devices. Narrow devices
transfer data one byte (or 8 bits) at a time. Wide devices transfer two bytes
(or 16 bits) at a time. The value given in the command line option will
determine the size of data transfers.

Usage: /WIDTH=n<hba[:id]>[,n<hba[:id]>]*

Where: 
       n = 8 or 16. 

       hba represents the logical number of a host adapter as displayed by the
       Verbose option in the column headed "HBA". This is not the SCSI ID of
       the host adapter. Use an hba value with no :id following it to indicate
       all devices on an adapter.

       id represents a SCSI target ID on the indicated adapter. To indicate all
       devices on a host adapter, do not use the SCSI ID of the host adapter
       for the id value. Instead, use the hba value as indicated in the
       preceding paragraph.

       [ ] indicate optional information.

       * indicates the pattern enclosed in the [ ] may be repeated.
 
For example, to have the device at ID 3 on host adapter 0 treated as a 
narrow device, the line in the CONFIG.SYS file that loads SYM8XX.ADD should 
look like this: 

       BASEDEV=SYM8XX.ADD /WIDTH=8<0:3>

As another example, to have all devices on host adapter 2 treated as 8-bit 
devices, the line in the CONFIG.SYS file that loads SYM8XX.ADD should look
like this:

       BASEDEV=SYM8XX.ADD /W=8<2>

 
*  *  *  *  *  *  *  *  *  *  * Troubleshooting *  *  *  *  *  *  *  *  *  *  *

Some potential problems and their suggested solutions are:

Problem: You cannot access the SCSI device(s). 
   
    Solution:

    a. Make sure the SCSI device driver is installed properly.
    b. Make sure each device has power.
    c. Verify that the appropriate BASEDEV= line (BASEDEV=SYM8XX.ADD /V 
       or BASEDEV=SYM_HI.ADD /V) exists in the CONFIG.SYS file. 
    d. Check the ordering of BASEDEV= entries in the CONFIG.SYS file to be
       sure that the boot device is loaded first.
    e. Verify that the correct driver is in the appropriate directory
       (\OS2\BOOT).
    f. Check the cable connections and the host adapter installation.
    g. Verify that the adapter is not turned off in the SCSI BIOS Configuration
       Utility and that the adapter is not excluded using the /EXCLUDE command 
       line option.

Problem: The computer hangs or locks up when booting and the SCSI devices
         attached are not seen by the computer system.
   
    Solution:

    a. Make sure that all the SCSI devices are configured at different ID 
       numbers. If booting the system from a device on the SCSI bus, the boot
       drive must have the lowest ID or the highest ID, depending on the scan
       order option selected in the SCSI BIOS Configuration Utility. For more
       information, consult the BOOTROM.TXT file or the documentation provided
       with the host adapter board.
    b. Make sure both, but only, the ends of the SCSI bus are terminated.
    c. Make sure the device driver is listed in the CONFIG.SYS file (and loaded
       when booting).

Problem: The device driver does not see one of the SCSI devices.

    Solution:

    a. Make sure the SCSI devices have different ID numbers. 
    b. Make sure both, but only, the ends of the SCSI bus are terminated. 
    c. Check the cable and power connections.
    d. Check the ordering of BASEDEV= entries in the CONFIG.SYS file to be sure
       that the boot device is loaded first.
    e. Verify that the adapter is not turned off in the SCSI BIOS Configuration
       Utility and that the adapter is not excluded using the /EXCLUDE command
       line option.
    f. Reboot the computer.

Problem: OS/2 attempts to install to or boot from an IDE drive instead of 
         the SCSI drive.

    Solution:

     The system BIOS finds the IDE drive before it finds the SCSI drive, and
     therefore uses the IDE drive as the boot device.

    a.  Check that the appropriate BASEDEV= line (BASEDEV=SYM8XX.ADD /V or 
        BASEDEV=SYM_HI.ADD /V) appears first in the CONFIG.SYS file.
    b.  Disable the IDE drive in the CMOS setup.
    c.  On some hardware platforms, the IDE drive must be physically disconnected
        before installing to a SCSI drive.

Problem: The following message appears at bootup: 

           "OS/2 is unable to operate your hard disk or diskette drive.
            The system is stopped. Correct the preceding error and restart
            the system."

    Solution:

    a. This problem occurs when the system is booting from a hard drive attached
       to an IDE bus, a SCSI disk is attached to the Symbios host adapter, and
       the Symbios BASEDEV= line (BASEDEV=SYM8XX.ADD /V or BASEDEV=SYM_HI.ADD /V)
       appears in the CONFIG.SYS file before the IDE device driver statement.

       -OR-

       This problem occurs when the system is booting from a hard drive attached
       to the Symbios adapter, an IDE drive is in the system, and the IDE
       BASEDEV= line appears in the CONFIG.SYS file before the Symbios BASEDEV=
       line (BASEDEV=SYM8XX.ADD /V or BASEDEV=SYM_HI.ADD /V).

      b. Boot the system using the floppy drive and installation diskettes to
         the F3=Command Prompt screen. Use the TEDIT.EXE editor to edit the 
         CONFIG.SYS file. Move the BASEDEV= statements to be in the appropriate
         order for the system's configuration.

      c. Restart your system. 
 