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                        OS2.TXT
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INSTALLATION GUIDE FOR THE SDMS OS/2 DRIVER V4.01.00


This file describes the features and use of the Symbios Logic SDMS
device driver for the OS/2 operating system environment.
It is divided into the following sections:

Introduction
        Features
        Description
Installing Your SDMS OS/2 Driver
        Installing SYM416.ADD
               (with OS/2 already installed)
        Installing SYM416.ADD and OS/2
               (from a floppy) to a SCSI Hard Drive
        Installing SYM416.ADD and OS/2
               (from a SCSI CD-ROM) to a SCSI Hard Drive
        Drive Order in the CONFIG.SYS File
        Command Line Options
        Troubleshooting



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


The OS/2 operating systems version 2.11 and later provide
an integrated platform featuring a graphical windowing
interface, called Presentation Manager, that allows
viewing multiple applications 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. These versions of OS/2 require an 80386 or
higher microprocessor. Other hardware requirements include
a minimum of 4 megabytes of RAM (8 megabytes or more is
recommended) and a minimum hard disk drive size of 40
megabytes. The SDMS SYM416.ADD driver provides the necessary
SCSI device driver for OS/2. We recommend reviewing the OS/2
manual prior to proceeding.


* Features *

Enhances host adapter performance
Supports synchronous negotiation
Supports Disconnect/Reselect
Supports scatter/gather


* Description *

The Symbios Logic SYM416.ADD device driver is written in
compliance with the IBM OS/2 ADD (Adapter Device Driver)
specification, and works with third party applications
that comply with the same specification.




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



These installation instructions are specific and accurate
for the SDMS OS/2 driver SYM416.ADD V4.01.00.




* Installing SYM416.ADD (with OS/2 already installed) *

The Symbios Logic device driver floppy diskette contains two files,
the device driver SYM416.ADD and a text file, SYM416.DDP.
When the device driver installation utility under OS/2 is
activated, it looks for a file with the DDP extension. The
DDP file contains the necessary information to install the
SCSI device driver.

1) At the OS/2 Desktop, open the System Setup folder, and
   double-click on the Device Driver Install icon.

2) Insert the floppy disk containing the Symbios Logic device driver
   in the source drive.

3) Click the install button.

4) Choose the Symbios Logic SYM416.ADD driver from the list provided
   by clicking on it once. The choice is highlighted.
   Then click the OK button, then the EXIT button.

5) To make sure that the installation is successful, open
   the productivity folder on the OS/2 Desktop, then
   double-click the OS/2 System Editor to start the editor.
   Open the CONFIG.SYS file and find the line:

       BASEDEV=SYM416.ADD /V /Q

   Then check that the file SYM416.ADD is in the
   appropriate directory (\OS2\BOOT) on the boot drive.


* Installing SYM416.ADD and OS/2
        (from a floppy) to a SCSI Hard Drive *

In this case, since you are installing OS/2 from a floppy
disk, the presence of the driver is not required to
install the operating system (as is the case when
installing from a CD-ROM).

1) After the installation of OS/2 is complete and the
   WorkPlace Shell desktop is built, open the system
   setup folder and double click on the Device Driver
   Install icon.

2) Insert the floppy disk containing the Symbios Logic device
   driver in the source drive.

3) Click the install button.

4) Choose the Symbios Logic SYM416.ADD driver from the list
   provided by clicking on it once. The choice is highlighted.
   Then click the OK button, then the EXIT button.

5) To make sure that the installation is successful,
   open the productivity folder on the OS/2 Desktop, then
   double-click the OS/2 System Editor to start the editor.
   Open the CONFIG.SYS file and find the line:

       BASEDEV=SYM416.ADD /V /Q

   Then check that the file SYM416.ADD is in the
   appropriate directory (\OS2\BOOT) on the boot drive.

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



* Installing SYM416.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 Logic
host adapter, the presence of the SCSI driver is required in order to
access the CD-ROM. The following steps allow installation
of OS/2 from a SCSI CD-ROM.

1) Make copies of the two floppy disks used for
   installation that are included with the CD-ROM version
   of OS/2. These disks are labeled "Installation Diskette"
   and "Diskette 1".

2) Copy the file SYM416.ADD from the Symbios Logic distribution
   disk to the copy of "Diskette 1".

NOTE: OS/2 Warp versions of "Diskette 1" do not contain
      enough available space to copy SYM416.ADD. You must delete 
      files in order to copy the driver onto the diskette. 

      When any .ADD drivers are deleted from "Diskette 1",
      make certain to delete or remark out the corresponding
      BASEDEV= statement in CONFIG.SYS. Otherwise, error
      messages show up during installation.

3) Edit the file CONFIG.SYS on the copy of "Diskette 1"
   by adding the following line at the end of the file:

        BASEDEV=SYM416.ADD /V /Q

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
you want the drive letters assigned. In particular:

   - OS/2 Warp installs 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.

   - If the system is to boot from a hard drive attached
     to an IDE bus, the IDE driver must appear before
     SYM416.ADD in CONFIG.SYS.

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


* Command Line Options *


The SYM416.ADD driver has several embedded functions
which are accessed via switches on the command line
in the CONFIG.SYS file. These options are described
below.


Using the /VERBOSE ( or /V ) Option:

    Usage:
        /VERBOSE

    This switch is used to output more detailed information than is usually
    shown, after the SYM416.ADD is initialized.

    For example, if you wish to see more detailed information displayed when
    you boot, the line in CONFIG.SYS that loads SYM416.ADD should look like
    this:

    BASEDEV=SYM416.ADD /VERBOSE

          or

    BASEDEV=SYM416.ADD /V

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


Using the /QUIET ( or /Q ) Option:

    Usage:
        /QUIET

    This switch is used to prevent the system from stopping during boot
    when a fatal error is detected during initialization of SYM416.ADD.

    For example, if you wish the system boot to proceed on error without
    waiting for operator input, the line in CONFIG.SYS that loads SYM416.ADD
    should look like this:

    BASEDEV=SYM416.ADD /QUIET

          or

    BASEDEV=SYM416.ADD /Q

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


Using the /!DM Option:

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

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

    For example, the /!DM statement:

          BASEDEV=SYM416.ADD /!DM:<0:3>,<0:5>

    disables OS2DASD.DMD on devices at target IDs 3 and 5
    (both at LUN 0).


Using the /SYNCH_RATE ( or /SR ) Option:

    Usage:
        /SYNCH_RATE=n<path[:id]>[,n<path[:id]>]*
        (n = 0, 5, or 10)

    This sets the maximum synchronous transfer rate (in mega transfers per
    second) to negotiate with a particular device.  The allowable values for
    this setting are 0, 5, and 10 mega transfers per second, if the
    adapter is capable of the specified speed.  The host adapter supports 10 mega
    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.

    For example, if you want to turn off synchronous transfers to
    ID=3, the line in CONFIG.SYS that loads SYM416.ADD should
    look like this:


    BASEDEV=SYM416.ADD /SYNCH_RATE=0<0:3>

    As another example, if you want to set synchronous transfers to 10 mega
    transfers per second on all devices on adapter 1, the line in CONFIG.SYS
    that loads SYM416.ADD should look like this:

    BASEDEV=SYM416.ADD /SYNCH_RATE=10<1>



Using the /SYNCH_OFFSET ( or /SO ) Option:

    Usage:
        /SYNCH_OFFSET=n<path[:id]>[,n<path[:id]>]*
        (n = 0..maximum synchronous offset for the adapter)

    This 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 path.  The SYM53C416 controller
    chip supports offsets up to 8.  If 0 (zero) is specified for the synchronous offset
    value, then 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 capability.
    The default value is the maximum offset that is supported by a particular 
    host adapter.

    For example, if you want to change the synchronous offset to 6 for
    ID=3, the line in CONFIG.SYS that loads SYM416.ADD should
    look like this:

    BASEDEV=SYM416.ADD /SYNCH_OFFSET=6<0:3>


Using the /DISCONNECT ( or /DC ) Option:

    Usage:
        /DISCONNECT=n<path[:id]>[,n<path[:id]>]*
        (n = ON or OFF)

    SCSI devices have the ability to disconnect from the bus during an I/O
    transfer.  This option is used to allow (or not allow) a device to
    disconnect during an I/O.

    Valid options are "ON" (allow disconnects) and "OFF" (do not allow
    disconnects).  The default for all devices is "ON".

    For example, if you want to disable disconnects on the device at
    ID=2, then the line in CONFIG.SYS that loads SYM416.ADD should
    look like this:

    BASEDEV=SYM416.ADD /DISCONNECT=OFF<0:2>




* Troubleshooting *


YOU CANNOT ACCESS THE SCSI DEVICES.

Make sure the SCSI device driver is installed properly.

Make sure each device has power.

Verify that a BASEDEV = SYM416.ADD /V /Q line exists in the CONFIG.SYS file.

Verify that SYM416.ADD is in the appropriate
directory (\OS2\BOOT) for your version of OS/2.

Check the cable connections and the host adapter installation.


THE COMPUTER HANGS OR LOCKS UP WHEN BOOTING AND THE SCSI
DEVICES ATTACHED ARE NOT SEEN BY THE COMPUTER SYSTEM.

Make sure that all the SCSI devices are configured at different ID numbers
(the boot drive must have the lowest ID).

Make sure both, but only, the ends of the SCSI bus are terminated.

Make sure the device driver is listed in CONFIG.SYS (and
loaded when booting).


THE DEVICE DRIVER DOES NOT SEE ONE OF THE SCSI DEVICES.

Reboot the computer.

Make sure the SCSI devices have different ID numbers (the
boot drive must have the lowest ID).

Make sure both, but only, the ends of the SCSI bus are
terminated.

Check the cable and power connections.


SYMBIOS LOGIC ADD ERROR: HOST ADAPTER IS MALFUNCTIONING.

This is typically an interrupt problem. Possibly the system BIOS
is not assigning interrupts properly. Since some
mainboard vendors require specific jumper settings to enable
the IRQ set by the CMOS, check your manufacturer's
documentation for proper jumper configurations. Then check
that the PCI slot setup in the CMOS is assigned and not in
conflict. If it is not assigned, it shows as NA. Assign
it a value. The only way to verify that it is in conflict
is to change the interrupt assigned to the slot in which the
Symbios Logic adapter is placed. If you no longer get the error, the
conflict is verified and you have successfully fixed the
problem.


THE FOLLOWING MESSAGE IS DISPLAYED 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."

This problem is caused when your system is booting from a hard
drive attached to an IDE bus, a SCSI disk is attached to your 
SYM416 host adapter, and the statement 

     BASEDEV=SYM416.ADD /V /Q

appears in the CONFIG.SYS file before the IDE device driver 
statement.

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=SYM416.ADD /V /Q statement
to the last line in the CONFIG.SYS file.

Restart your system.


