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                                  WIN95.TXT
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INSTALLATION GUIDE FOR THE SDMS DRIVER SYMC8XX.MPD V4.03.00

This file describes the features and use of the Symbios Logic SDMS device 
driver for the Windows 95 operating system environment. It is divided into 
the following sections:

Introduction for Windows 95
     Features
     Description

Installing Your SYMC8XX.MPD Driver
     Preparing a Symbios Driver Diskette
     New System Installation
     Existing System Installation
     Existing System Using ASPI8XX.SYS DOS ASPI Driver
     Verifying Correct Driver Installation
     Command Line Options
     Troubleshooting

Important Additional Information
     Enabling/Disabling Ultra SCSI (Fast 20) Support
     Disabling Auto Request Sense Support
     Disabling SCAM Support
     Multiple Symbios Logic Host Adapter Considerations


************************ Introduction for Windows 95 ************************ 

Windows 95 is an operating system designed to run on Intel processors using 
current technology. It provides a graphical user interface environment 
incorporating many high-level features (refer to the Microsoft Windows 95 
documentation for details). I/O requests in Windows 95 are handled by an I/O 
manager. To address a SCSI peripheral, the I/O manager goes through the 
appropriate drivers. Class drivers for hard disk, floptical, CD-ROM, printer, 
and scanner peripherals are provided in Windows 95. Other class drivers, 
provided by peripheral manufacturers, are added to support new devices. 
Symbios Logic/Microsoft provide a miniport driver, called SYMC8XX.MPD, to 
complete the path to a Symbios Logic controller or processor with an optional 
SDMS SCSI BIOS. The following sections describe this driver and its 
installation.


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

o  Synchronous negotiation (including Fast/Ultra SCSI) 
o  Wide negotiation 
o  Auto Request Sense 
o  Supports multiple host adapters 
o  Supports multiple Logical Unit Numbers (LUNs) 
o  Disconnect/Reselect 
o  Scatter-Gather 
o  Differential Support 
o  Supports SCSI pass-through functionality 
o  BUS device reset 
o  Scan order change (scans the bus from SCSI ID 0 to MAX SCSI ID [7 or 15]) 
o  Ultra SCSI (Fast 20) Support (20 MB/s narrow, 40 MB/s wide) 
o  SCAM Support (SCSI Configured AutoMatically) 
o  Target initiated negotiation support 
o  Renegotiation of wide/sync parameters on request sense commands 
o  Full NVRAM support (wide/sync parameters, SCSI ID, SCAM on/off) 


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

SYMC8XX.MPD is designed to Microsoft's specification for miniport drivers. 
This driver allows connection of SCSI devices including disk drives, CD-ROMs, 
and tape drives for PCI-based machines. To support a new SCSI device, the 
Windows 95 architecture requires that a class driver for that type device is 
present (usually supplied by Microsoft, or possibly by the peripheral 
manufacturer). No changes to SYMC8XX.MPD are required. This driver is only 
supported under Windows 95. 

SCSI commands are passed directly from a Windows application to the SCSI 
devices by using the SCSI pass-through facility (refer to the Microsoft 
Windows 95 documentation for details). This facility allows applications to 
directly control and access SCSI devices by filling in a data structure and 
calling in to the port driver.

The SYMC8XX.MPD driver supports Ultra SCSI protocol, providing twice the raw 
data transfer rate of Fast SCSI for disk drives and Symbios Logic host 
adapters that support Ultra SCSI. However, Ultra SCSI requires more stringent 
SCSI bus cabling setups than Fast SCSI.


********************* Installing Your SYMC8XX.MPD Driver ******************** 

*  *  *  *  *  *  *  * Preparing a Symbios Driver Diskette *  *  *  *  *  * 

Copy the files listed below (supplied to you on diskette) to the root 
directory of a clean floppy diskette, and use this Symbios Driver diskette 
during installation.

     SYMC8XX.MPD   
     SYMC8XX.INF   


*  *  *  *  *  *  *  *  *  New System Installation *  *  *  *  *  *  *  *  *

This procedure installs the SYMC8XX.MPD driver onto a Windows 95 system. Use 
this procedure when initially upgrading to Windows 95. Windows 95 
automatically adds the driver to the registry and copies the driver to the 
appropriate directories.

NOTE: Some Symbios Logic PCI SCSI host adapters are supported by a driver 
      bundled in Windows 95. For these adapters, the bundled driver is 
      automatically installed during Windows 95 Setup. To change to the 
      SYMC8XX.MPD driver, follow the instructions for Existing System 
      Installation after Windows 95 installation is completed.

1. Initiate Windows 95 Setup according to the Microsoft instructions.

2. Setup enters the hardware detection phase after a system reboot. ("Setting 
   up Hardware" message box is displayed.) If the message "Symbios Logic PCI 
   SCSI Host Adapter" displays, then the host adapter supports the bundled 
   driver, and it installs automatically. After the Windows 95 installation 
   completes, you can install the SYMC8XX.MPD driver according to the 
   "Existing System Installation" instructions.

3. If the host adapter is not supported by the bundled driver, Setup displays 
   a New Hardware Found - PCI SCSI Bus Controller dialog box. Select "Driver 
   from disk provided by hardware manufacturer" and click OK.

NOTE: If ASPI8XX.SYS (the Symbios Logic SDMS 4.0 DOS ASPI driver) is loaded 
      when beginning the Windows 95 installation, no messages about PCI SCSI 
      Bus Controllers is displayed. The installation completes, but real-mode 
      disk drivers are used. See Verifying Correct Driver Installation below. 
      To install the SYMC8XX.MPD driver, (which disables loading of the 
      ASPI8XX.SYS driver under Windows 95) see Existing System Using 
      ASPI8XX.SYS DOS ASPI Driver below. 

4. Insert the Symbios Driver diskette into drive A: (or B:) (the one prepared 
   in * Preparing a Symbios Driver Diskette *) and click OK. If using drive 
   B:, you must select it from the pick list.

5. Windows 95 automatically copies the appropriate driver files and rebuilds 
   its driver database.

6. A "System Settings Change" dialog box is displayed. Remove the flex disk 
   from the drive and click Yes to restart the computer.

At this point, Windows 95 Setup completes and the new driver is operational. 
To verify this, see the section "Verifying Correct Driver Installation"


*  *  *  *  *  *  *  *  * Existing System Installation *  *  *  *  *  *  *  *

This procedure installs the SYMC8XX.MPD driver onto an existing Windows 95 
system.

1. Boot Windows 95.

2. Click Start. Move to Settings, Control Panel, and click.

3. Double-click on the System icon.

4. Click on the Device Manager tab.

NOTE: If the SCSI controllers entry, or the PCI Symbios Logic C8xx SCSI 
      Host Adapter entry do not exist, the system is probably using the 
      ASPI8XX.SYS DOS ASPI driver. See the Existing System Using ASPI8XX.SYS 
      DOS ASPI Driver section below.

5. Either double-click on the SCSI controllers entry, or click once on the 
   plus sign to the left of it.

6. Select the PCI Symbios Logic C8xx SCSI Host Adapter entry. Click the 
   Properties button.

7. Click the Driver button. The version of the currently active driver should 
   display in the File details section.

Note: In certain versions of Windows 95, the version of the active driver
      is displayed as Not available. This is an OS issue and is fixed in later 
      versions of Windows 95. To verify the version of the driver, click 
      on the Properties field of the SYMC8XX.MPD file under the Version 
      tab. The MPD driver is generally found in the \WINDOWS\SYSTEM\IOSUBSYS\ 
      directory.

8. Click the Change Driver... button.

9. Even though you may have previously installed the SYMC8XX.MPD driver, 
   click the Have Disk... button to install a newer version.

10. Insert the Symbios Driver diskette in drive A: (or B:) (the one prepared 
    in * Preparing a Symbios Driver Diskette *) and click OK. If using drive 
    B:, you must select it from the pick list.

11. The Select Device dialog box should display "Symbios Logic 8xxxx PCI SCSI 
    Host Adapter", where 8xxxx matches the installed adapter. Click OK.

12. The Driver tab is updated to display the new driver files. To install 
    these driver files, click OK. (Do NOT click the Change Driver... button.) 
    The driver files are copied and a new driver database is built.

13. A "System Settings Change" dialog box is displayed. Remove the flex disk 
    from the drive and click Yes to restart the computer.

At this point, the new driver is operational. To verify this, see the section 
"Verifying Correct Driver Installation"


* Existing System Using ASPI8XX.SYS DOS ASPI Driver *

This procedure installs the SYMC8XX.MPD driver onto an existing Windows 95 
system which is using the ASPI8XX.SYS DOS ASPI driver. You can check this by 
using the Verifying Correct Driver Installation instructions below.

1. Boot Windows 95.

2. Click Start. Move to Settings, Control Panel, and click.

3. Double-click on the System icon.

4. Click on the Device Manager tab.

5. Either double-click on the Other entry, or click once on the plus sign to 
   the left of it.

6. Select the PCI SCSI Bus Controller entry. Click the Properties button.

7. Click the Driver button. A message should state that no drivers are 
   installed for this device.

8. Click the Change Driver... button.

9. In the Select Hardware Type dialog box, select SCSI Controllers.

10. In the Select Device dialog box, click the Have Disk button.

11. Insert the Symbios Driver diskette in drive A: (or B:) (the one prepared 
    in * Preparing a Symbios Driver Diskette *) and click OK. If using drive 
    B:, you must select it from the pick list.

12. The Select Device dialog box should display "Symbios Logic 8xxxx PCI SCSI 
    Host Adapter", where 8xxxx matches the installed adapter. Click OK.

13. The Driver tab is updated to display the new driver files. To install 
    these driver files, click OK. (Do NOT click the Change Driver... button.) 
    The driver files are copied and a new driver database is built.

14. A "System Settings Change" dialog box is displayed. Ignore the message
    saying to turn off your computer and change hardware settings. Remove the 
    flex disk from the drive and click Yes to shut down the computer. Press 
    Ctrl-Alt-Delete or the system reset button to restart the system.

At this point, the new driver is operational. To verify this, see the section 
"Verifying Correct Driver Installation"


*  *  *  *  *  *  *  Verifying Correct Driver Installation *  *  *  *  *  *

After installing/updating with the SYMC8XX.MPD driver, you should verify 
proper operation of the driver.

1. Check that all devices on the SCSI bus are available via My Computer. 
   Double click on the My Computer icon. Check that all logical SCSI hard 
   drives and CD-ROM drives are shown.

2. Click the Start button, move to Settings, Control Panel, and click. Double
   click on the System icon. Click the Device Manager tab. Check that no host 
   adapter is displayed with a yellow or red symbol under the SCSI 
   controllers entry. If there is, continue with the steps below to help 
   determine the problem.

3. Either double-click on the SCSI controllers entry, or click once on the 
   plus sign to the left of it. One entry for each host adapter installed in 
   the system is displayed. Select an entry, then click the Properties 
   button. The Device Status message should read "This device is working 
   properly." If any other messages appear, continue with the steps below to 
   get more information on the problem.

4. Click the Driver tab. Two entries should appear, one for SYMC8XX.INF and 
   one for SYMC8XX.MPD. The INF file does not contain embedded version 
   information, so the File Details are all Not Available. Select the 
   SYMC8XX.MPD file. The file version of the driver is displayed.

5. Click Cancel to leave the Host Adapter Properties dialog box. Click on the 
   Performance tab. A list of performance attributes is displayed. Below the 
   list, you should see the message "Your system is configured for optimal 
   performance." If any other messages appear, select each message and click 
   the Details button. This provides more information on why the system is 
   not performing optimally and methods to correct the problem.

If no problems are encountered in the above steps, the new driver is 
operating properly. Otherwise, consult the section on Troubleshooting for 
additional information.


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

There are no command line options with the Windows 95 device driver.


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

The following are some problems their suggested solutions:

*   *   * Problem *   *   *

During Installation, No SCSI Devices Are Found.

*   *   * Solution *   *   *

a. Ensure that all devices are powered on and terminated correctly.

b. Check that no devices have duplicate SCSI IDs.

c. Make sure INT A is assigned for the PCI slot(s) where your SCSI host 
   adapter(s) are installed.

*   *   * Problem *   *   *

System Crashes During Installation With A Message Indicating Inaccessible 
Boot Device.

*   *   * Solution *   *   *

a. This error is usually associated with an IRQ, DMA channel, I/O (chip) 
   address, or BIOS address conflict. Set the SCSI host bus adapter board to 
   use a different interrupt.

*   *   * Problem *   *   *

Problems With Ultra SCSI Devices Using Ultra SCSI Protocol.

*   *   * Solution *   *   *

a. If the system is configured with a Symbios Logic host adapter that 
   supports Ultra SCSI, an Ultra SCSI device is on the SCSI bus, and Ultra 
   SCSI support by the SYMC8XX.MPD driver is enabled, intermittent problems 
   and possible system crashes can occur if the SCSI bus cable and 
   terminators do not conform to the Ultra SCSI specification.

b. If the system is bootable, disable Ultra SCSI support using the procedure 
   described below.

c. If the system is not bootable to Windows 95, hold down F8 when Starting 
   Windows 95... is displayed. At the menu, select Safe Mode. Once the system 
   is booted, disable Ultra SCSI support using the procedure described below.

d. If the system operates properly without Ultra SCSI enabled, it is highly 
   likely that the SCSI bus cable and terminators are not configured 
   correctly for Ultra SCSI. See the Symbios Logic host adapter hardware 
   manual for information on Ultra SCSI cabling requirements.

*   *   * Problem *   *   *

Problems With Scanners

a. If a scanner is not operating properly (either the scanner is not found or 
   a SCSI interface error occurs during scanning), it is possible that the 
   third-party scanner drivers do not support the auto request sense feature 
   of Symbios Logic host adapters. Disable the auto request sense feature as 
   described below and try the scanner operation again.


********************** Important Additional Information ********************* 

*  *  *  *  *  * Enabling/Disabling Ultra SCSI (Fast 20) Support *  *  *  *

Ultra SCSI (Fast 20) support is controlled by settings in the adapter NVRAM. 
These settings can be viewed or changed via the Configuration Utility. During 
system boot, after the Symbios Logic PCI BIOS banner, the message "Press 
Control-C to start Configuration Utility" is displayed for a few seconds. By 
pressing Control-C, this utility is started.

Select one of the adapters displayed, then "Device Selections". This shows 
the Sync Rate for each device and the selected adapter. To set a device to 
Ultra, the speed should be set to 20 (for width of 8) or 40 (for width of 
16). To disable Ultra, the speed should be no higher than 10 (for width of 8) 
or 20 (for width of 16). If the speed of the adapter itself is changed, the 
speed for all devices will be set no higher than the adapter speed.


*  *  *   *  *  *  * Disabling Auto Request Sense Support *  *  *  *  *  *  *

When the SYMC8XX.MPD driver is installed, support for auto request sense is 
enabled. Auto request sense is a feature of the adapter where certain device 
information is obtained automatically without system control, thereby 
increasing overall performance. However, some third-party peripheral drivers 
do not support the use of auto request sense, resulting in perceived device 
failures. Therefore, to allow these devices to operate properly, the auto 
request sense feature can be disabled using the Device Manager on a per 
adapter basis.

Use this procedure for disabling auto request sense support:

1. Click the Start button, move to Settings, Control Panel, and click. Double 
   click on the System icon. Click the Device Manager tab.

2. Either double-click on the SCSI controllers entry, or click once on the 
   plus sign to the left of it. One entry for each host adapter installed in 
   the system is displayed. Select the adapter desired, then click the 
   Properties button. Click the Settings tab.

3. In the Adapter settings entry, type "DisableAutoReqSense=1;", without 
   the quotes. If there is already an entry displayed, type the above at the 
   end of the existing entry. Be sure to include the semi-colon.

4. Click OK to exit the Settings tab.

5. Click OK again. If the entry was changed, the "System Settings Change" 
   dialog box is displayed. Click Yes to restart the computer.

After the system reboots, auto request sense is disabled for the 
selected adapter. To re-enable auto request sense, delete the entry that was 
made above. If other entries exist, be sure to leave them intact.


*  *  *  *  *  *  *  *  * Disabling SCAM Support *  *  *  *  *  *  *  *  *

SCAM (SCSI Configured AutoMatically) is a protocol that allows SCAM-compliant
peripherals to assign their SCSI ID's dynamically at boot time, eliminating
the need for the user to check and set unique SCSI ID's. This feature is
enabled by default in the Symbios PCI BIOS and the SYMC8XX.MPD driver. Some
legacy (non-SCAM) peripherals have problems with the SCAM protocol, resulting
in the device either not being seen by the operating system, or not working
correctly. As a workaround, SCAM can be disabled to allow the device to
function. There are two methods for disabling SCAM. In either case, all SCSI
ID's on a particular SCSI bus must be unique when SCAM is disabled.

Method 1

This method is used when the adapter has NVRAM. During system boot, after the
Symbios Logic PCI BIOS banner, the message "Press Control-C to start
Configuration Utility" is displayed for a few seconds. By pressing Control-C,
this utility is started.

Select the desired adapter, then "Adapter Setup". On the Adapter Setup menu,
highlight "S-SCAM Support" and press enter. Use the up/down arrows to select
the OFF setting, and press enter. Exit from the menus and save the settings.
This will turn off SCAM for both the PCI BIOS and the SYMC8XX.MPD driver. To
re-enable SCAM, repeat the above procedure to change the setting to ON.

Method 2

For adapters that do not have NVRAM, SCAM can be disabled within Windows 95:

1. Click the Start button, move to Settings, Control Panel, and click. Double
   click on the System icon. Click the Device Manager tab.

2. Either double-click on the SCSI controllers entry, or click once on the
   plus sign to the left of it. One entry for each host adapter installed in
   the system is displayed. Select the adapter desired, then click the
   Properties button. Click the Settings tab.

3. In the Adapter settings entry, type in "no_SCAM=1;", without the quotes. If
   there is already an entry displayed, type the above at the end of the
   existing entry. Be sure to include the semi-colon.

4. Click OK to exit the Settings tab.

5. Click OK again. If the entry was changed, the "System Settings Change" 
   dialog box is displayed. Click Yes to restart the computer.

After the system reboots, SCAM will be disabled for the selected adapter. To
re-enable SCAM, delete the entry that was made above. If other entries exist,
be sure to leave them intact.


*  *  *  *  *  Multiple Symbios Logic Host Adapter Considerations *  *  *  *

If multiple Symbios Logic PCI SCSI host adapters are installed in the system, 
special actions are sometimes required to install or change drivers. This is 
due to the fact that some Symbios Logic host adapters are supported by the 
bundled driver, and also that one Symbios driver supports all Symbios host 
adapters installed in the system.

With multiple Symbios adapters, it is possible to have a situation where one 
adapter is assigned to one driver, and another is assigned to a different 
driver. This can cause conflicts which may cause the system to switch to real 
mode drivers, affecting performance and access to CD-ROM or tape drives.

There are two methods for ensuring that all Symbios Logic host adapters are 
controlled by only one driver (when installing additional boards or updating 
drivers).

*   *   * Method 1 *   *   *

Using the Device Manager, change the driver for a particular host adapter to 
the desired driver, but when asked to reboot the system for the new settings 
to take effect, click No. Change drivers for all Symbios Logic host adapters 
in the system to the new driver, and reply No to rebooting until the final 
adapter is changed. If booting from a SCSI device, check that the adapter 
controlling this device is the last one changed.

*   *   * Method 2 *   *   *

Determine which driver file is active for all adapters through the Properties 
tab in Device Manager. Go to the \WINDOWS\SYSTEM\IOSUBSYS directory and 
rename the driver file to an extension other than MPD. Reboot the system. 
While booting, the system may ask to load the bundled driver file from the 
Windows 95 installation disk. Click OK, then when the system says it cannot 
find the file, click Skip File. Do this for all adapter messages while 
booting. After the system is booted, use the Device Manager to change the 
driver for each adapter to the desired driver. Do not reply Yes to reboot the 
system until the final adapter has been changed.

