Table of Contents

Removing SCO Merge components

• Windows
• DOS and Windows applications
• Personal DOS and Windows session configuration files
• Custom Device definitions
• System-wide configuration files

If necessary, you can remove these components manually as follows:

• To remove Windows, remove the directory where it is installed. This can be done even if SCO Merge is not removed -- in order to reinstall Windows 95, for example.

  To remove Windows which is installed on your personal drive, run the following command:
  

  rm -rf $HOME/merge/windows

  .
• To remove the complete personal SCO Merge installation including Windows, applications, and personal session configuration files, run the following commands:
  

  rm -rf $HOME/merge
  rm -rf $HOME/.merge
  

• To remove all system-wide SCO Merge components run the following command as root:

  rm -rf /usr/merge
  rm /etc/default/merge
  

When you install Excel 5.0 with Windows installed in the C:\windows directory, make sure C:\config.sys exists. If C:\config.sys does not exist, you see the following message at the end of the Excel installation:

        cannot open d:\autoexec.tmp

Installing Paradox

To install Paradox on a particular drive, you must have permission to create directories in the root directory of that drive. (Paradox tries to create the directory \odapi there).

If you don't have the right permissions, Paradox will complain with the following message:

Invalid drive specification

To avoid this problem, install Paradox on your personal drive (usually drive C) or any DOS drive. If you need to install Paradox someplace else, you can create a new UNIX drive using the Merge Setup GUI. Designate the root of this drive to be the directory where you have write permission, and then install Paradox on that drive.

DOS and Windows application disk searches

During installation or upgrade procedures, some DOS and Windows applications search the fixed disk for existing versions of themselves or for other applications.

All drives that are attached to your DOS and Windows sessions will be searched including any parts of the UNIX file system that you have configured as a drive. Searching the entire UNIX file system can take a very long time (even several hours), especially if NFS is being used to connect to several large remote file systems. It is also not useful for the installation of a DOS or Windows application.

To avoid long searches, make sure you do not attach the entire UNIX file system as a drive to your DOS and Windows sessions. Create drives for only those parts of the UNIX file system that you know you will need.

Windows 3.1 Swap file

When Windows 3.1 is configured to use virtual memory, by default it automatically creates a temporary swap file on drive C called WIN386.SWP and deletes it when you quit Windows. (You cannot use a permanent swap file with SCO Merge. To use permanent swap files, Windows requires low-level disk access, which is not possible when running Windows on a UNIX system.)

If accessing your C drive is slow for some reason (such as when it is a remote NFS filesystem or is heavily used in a multi-user setting) or is low on free space, you can improve performance by changing the location in which Windows creates the temporary swap file.

To change the location of the temporary swap file, find the following line in the Windows system.ini file (this file is in the directory in which you installed Windows):

	PagingFile=C:\WINDOWS\WIN386.SWP

Change the drive and pathname following PagingFile= to the new location. If you choose to put the swap file in a common directory where others may also locate their swap files, you must be very careful to use a unique filename. Once you finish making the change to system.ini, restart Windows to have the change take effect.

Starting Windows with insufficient memory

NOTE: We recommend that you start Windows under SCO Merge from the UNIX command line or from the Desktop, as described in ``Beginning DOS and Windows sessions''.

Windows sessions hang or die if they are configured with only 1 MB of memory. This happens if you start Windows by running the win command from the DOS prompt using the standard DOS configuration; or if you change your Windows configuration to specify only 1 MB of memory.

Some of the symptoms you might see if you do not have enough memory include:

• When running on the Desktop, the Windows session appears to hang after displaying the logo. To see the error, if you are running on the Desktop, type the win /b command at the DOS prompt.

• When you use the win command at a UNIX prompt or use the Win utility, the Windows session dies after displaying the logo.

• When you use the win command at a DOS prompt when running full screen, Windows exits after displaying the logo, with the error:

      Insufficient extended memory to run Windows in
      standard mode.
      Increase the amount of available extended memory.
  

NOTE: To run Windows directly from a DOS command line, you must be running a DOS session started with enough standard memory. For Windows 3.1, the minimum amount needed is 4 MB although performance is often better with 6MB or more. For Windows 95, you should use 16 MB or more of standard memory.

To change your DOS configuration to increase the amount of memory run Merge Setup, click on the Personal Merge Session Configuration: dos button, and set the amount of standard memory in the Memory area. Click the Start button to start only this session with the set amount of memory. (Alternatively, you can use the dos +mmegabytes command to start the DOS session with megabytes MB of standard memory.)

Configuring SMARTDRV caching

By default, SCO Merge configures SMARTDRV to have a 512KB cache for DOS and Windows 3.1. This is normally enough for floppy disk use and avoids taking too much memory. Since only true DOS volumes benefit from using SMARTDRV, a larger cache just takes memory away from Windows.

However, if you use DOS volumes or CD-ROMs with MSCDEX, you could benefit from a larger SMARTDRV cache. If you specify larger or smaller values on the SMARTDRV command line, SCO Merge does not override them. For the CD-ROM to be cached, SMARTDRV must come before MSCDEX in your autoexec.bat file.

Windows display driver mismatch

If you run Windows under SCO Merge and there is a mismatch between the display setting and the Windows display driver, the Windows session dies. This can happen either in full-screen mode or on the Desktop.

For example, a mismatch would occur if you selected the Windows VGA display driver and then ran win +acga, or if you selected the DOS Merge Windows/X display driver and then ran win +acga.

When Windows dies, it displays the message:

      Video initialization failed.
      You need to run the Setup program again.

To use the CGA display setting for Windows on the Desktop, you must use one of the DOS Merge Windows/X CGA Windows display drivers.

Limits on simultaneously open files

On DOS file systems, there is no limit on the number of simultaneous open files. UNIX file systems do have a limit, so many applications (for example, FoxPro, Word, Paradox, and WordPerfect) exhibit problems when they have too many open files (or if they fail to close files they are no longer using).

Use the SCO Merge MERGE_MAXOPEN variable to set the open file limit for your UNIX file systems when running DOS and Windows. Set this variable either in /etc/default/merge (for all users) or in each user's environment. For example, the following setting in /etc/default/merge sets the open file limit to 1000:

        MERGE_MAXOPEN=1000

Note: Setting the number too large can allow a program to use up critical system resources, which results in problems when you start up new UNIX processes.

The open file limit problem exhibits different symptoms in different applications, including:

• FoxPro
• Word for Windows
• Paradox
• WordPerfect
• Microsoft Office

Searching deeply nested directories

DOS limits the length of full directory names to 64 characters, excluding the drive specification, but UNIX has no such limit. Therefore, when you access deeply nested directories on the UNIX file system from DOS, you may see unpredictable behavior.

Because DOS and Windows programs sometimes search entire drives (often without your knowledge) and a typical UNIX file system can be deeply nested, do not attach the entire UNIX file system as a drive to your DOS sessions to avoid these problems.

Changing the CD-ROM timeout

This timeout period is set to 18 seconds by default. It can also be configured using the MERGE_CD_RELEASE_SECONDS environment variable. Set this variable in the /etc/default/merge file to the number of seconds you want the timeout value to be prior to starting your DOS or Windows session.

The timeout value should not be set to a very low number since this will adversely affect the CD-ROM performance. Every time the CD-ROM device is released, all cached data is lost. Consequently, if the timeout value is too low, the CD-ROM data will have to be re-read unnecessarily.

Limited support for CD-XA CD-ROMs

If one or more files on a CD-ROM appears to be unviewable or unreadable under DOS or Windows 3.1 (that is, the dir command fails to display these files), you may have a CD-XA CD-ROM. In the default SCO Merge environment, CD-XA support is turned off for DOS and Windows 3.1

To turn on CD-XA support, insert the following merge command in your autoexec.bat file immediately before the mscdex command (if there is one):

	merge set cdxa on

Although we are not aware of any applications that fail when CD-XA support is turned on, you should try turning CD-XA support off if you experience failures with applications that use CD-ROMs. To turn off CD-XA support, change the merge command in your autoexec.bat file to:

	merge set cdxa off

DOS programs and CPU idle time

Some DOS applications, such as DOS edit, and some Windows applications can cause the CPU idle time to fall to zero. These applications run in an idle loop (also known as a busy loop or a polling loop), which continuously checks to see if there has been keyboard or mouse activity.

Having a CPU idle time of zero does not necessarily mean that the system is out of CPU resources, because applications with idle loops mostly use otherwise idle time and do not normally take CPU time away from other processes. However, if you are running a CPU-intensive application (one that by itself could use most of the available CPU time), simultaneously running a DOS or Windows application that has these idle loops wastes some CPU resources.

To avoid common idle loops, SCO Merge has the pollsleep feature, which is normally on and uses a special DOS console driver (hicon). These features are sufficient to prevent most DOS and Windows applications from doing idle loops. However, a few, such as DOS edit, cannot be prevented from using their idle loops, and you should only use these DOS or Windows applications when your system is not being taxed by another CPU-intensive application.

DOS file attributes

The DOS archive, system, and hidden file attributes do not exist on UNIX file systems. Therefore, when you access files from DOS or Windows using UNIX drives, you cannot use these attributes as you can on a DOS file system.

When you access UNIX files from DOS or Windows, the archive attribute is always on and the system and hidden attributes are always off. The DOS attrib command cannot change these attributes, the /m option of the xcopy command does not work, and the /a option of the xcopy command has no meaning.

Limitations on simultaneous sessions

By default, SCO Merge allows 32 simultaneous DOS and Windows sessions provided you have enough memory and swap space to start them. You can increase or decrease this limit by changing the MERGE_MAX_SESS tunable driver parameter using the following command (logged in as root):

	idtune MERGE_MAX_SESS value

value is the new limit for the parameter.

For information on tuning OpenServer systems, see "Using idtune to reallocate kernel resources" in Appendix B of the OpenServer Performance Guide.

For information on tuning UnixWare 7 systems, see ``Understanding tunable parameters'' in the ``Performing basic system tuning and monitoring'' part of the ``Systems Management'' document.

Also refer to the idtune(1M) manual page.

If you increase the MERGE_MAX_SESS parameter above 64, you must create additional device nodes by adding entries to the node files vkbd, vdsp, svdsp, and svkbd in the /etc/conf/node.d directory. See the mknod(C) manual page for information.

On OpenServer systems, a DOS session may fail when approximately 28 sessions are running on a normally configured SCO Merge system, because the system runs out of SEMMNU resources. When this happens, the DOS session starts, hangs for a few seconds, then dies with the message:

        VM_DIED: dos: ERROR: The VM86 session died.

TEMP and TMP directories

Many applications use the TMP and TEMP environment variables to determine the location of temporary directories. You can define these variables in your personal autoexec.bat file as you would on a standalone Windows machine.

If you do not have these variables defined at the time you install Windows 95, however, SCO Merge automatically configures the TMP and TEMP variables to refer to the temporary directory C:\windows\temp.

Root user home directory

XGA display adapters

SCO Merge does not support XGA and other higher-than-VGA-resolution display adapters when running DOS or Windows in full screen mode.

Windows hangs because of unsupported VxD

SCO Merge supports a wide variety of Windows 95 applications and some Windows 95 third-party drivers; however, if a VxD is included, it is possible that SCO Merge will not be able to support the device. (This is due to address space manipulations that SCO Merge has to do in order to co-exist with UNIX and with a limitation of the x86 processor, which does not allow complete virtualization of the x86 instruction set in protected mode.)

If you install an application or device driver that configures a VxD as part of the Windows 95 boot process, Windows 95 might not start.

You might be able to fix this problem with the following procedure:

1. From a UNIX prompt:

   
   cd $HOME/merge/windows/system
   ls -lctr | grep -i 'vxd'
   cd vmm32
   ls -lctr | grep -i 'vxd'
   
   

   Take note of the most recently added VxD files.

2. If you can identify the unsupported VxD, move it aside with:

   
   mv fancydev.vxd fancydev.vxd.bad
   
   

3. Start Windows 95.

   You will probably get a message about a needed VxD that is missing, but you should be able to press <Enter> and continue.

4. Once Windows 95 is up, remove the software package with Add/Remove_Programs. (You can access it from the Control Panel window by clicking on the Start button and selecting Settings from the menu.)

   You might have to move the VxD file back to its original name before doing this in order for the package removal to work correctly.

After you have identified the VxD, instead of moving it aside, an alternative approach is to edit the Windows 95 registry and remove entries associated with the unsupported VxD. (Be careful to not corrupt your Windows 95 registry.)

Start a SCO Merge DOS session with the Windows session configuration:

dos +w

Edit the file cur.reg, which has an ASCII (editable) version of your Windows 95 Registry.

 C> regedit /e cur.reg

Search for the entries associated with the suspect VxD and delete them. Save the file and quit the DOS session.

Then, rebuild the registry with:

dos +w
 C> regedit /c cur.reg

You should now be able to start Windows 95 successfully.

Mouse tracking speed under Windows

When you run Windows on the Desktop, SCO Merge requires that the mouse tracking speed be set to the slowest possible value and sets this speed automatically. Do not try to change the mouse tracking speed by using the Mouse dialog from the Windows Control Panel.

If the mouse tracking speed is not set to the slowest possible value, SCO Merge automatically restores the slow setting any time you exit the Mouse dialog box.

If you are having problems double-clicking in Windows, use the Mouse dialog in the Windows Control Panel to set the double-click speed to the slowest possible value.

Windows application tutorials

Some tutorials for Windows applications only work correctly when the screen is in 640x480 mode. These tutorials place objects on the screen incorrectly; so, when the screen resolution is less than 640x480, graphic and text items appear truncated or clipped. When the screen resolution is greater than 640x480, text and graphics are also confused. The only workaround is to change the screen resolution to 640x480.

Incorrect Windows size

Occasionally, you are given the option to restart Windows 3.1 after you install a Windows application. Sometimes, when you restarting Windows 3.1 from the Desktop, the window does not resize properly. If this happens, exit Windows and start another Windows session.

Windows Clipboard image corruption

If you save a large bitmap from the Windows Clipboard while running Windows on the Desktop, the bitmap may become corrupted.

Windows and 16-color VGA graphics

You cannot run a DOS application program that uses 16-color VGA graphics in a DOS window under Windows (also known as a DOS box) when you are working on the Desktop. If you try to do this, the display in the DOS window is garbled.

To run a DOS program that uses 16-color VGA graphics, start the DOS box in Windows full-screen mode and zoom it before you start the DOS application program.

Resizing under Windows

If you select one of the DOS Merge Windows/X CGA display settings and start a DOS window under Windows (also known as a DOS box), resizing the window often does not work properly. For example, if you grab the DOS box's right border and shrink the window slightly, the text that was in the window often wraps at the 40-column point instead of truncating at the right edge of the window. This problem can also occur when you use the Font menu option to change the font size in the DOS box.

To avoid this problem, do not shrink the window size. If the problem occurs while you are changing fonts, you may have to close the DOS box and restart DOS before you can resize the window properly. Always pick your font size as soon as you start your DOS box, before running any DOS applications.

Switching between Windows tasks

On some Desktops, using the standard Windows 3.1 <Alt><Tab> sequence to switch between Windows tasks does not work because some X window managers (including the Motif Window Manager, mwm, the Panorama Window Manager, pmwm, and CDE's window manager, dtwm) intercept the <Alt><Tab> key sequence by default, preventing SCO Merge from seeing it.

If this is a problem on your Desktop, you can work around it in either of the following ways:

• Under Windows 3.1, press <Ctrl><Esc> twice to display the Windows Task List dialog box, and use the dialog box to switch between tasks. Under Windows 95, press <Ctrl><Alt><Del>.

• Configure the Window Manager so that it does not use <Alt><Tab>.
  Refer to the mwm(X1), pmwm(X1), and dtwm(1), manual pages.
  On OpenServer systems see "Customizing the window manager" in Chapter 12 of the OpenServer Graphical Environment Guide.

Running out of X server memory

Some Windows applications perform memory-intensive activities that can cause your workstation or X terminal to run out of memory. Some examples include trying to run PowerPoint's Quick Preview (because of the way that PowerPoint manages bitmaps) or copying a large number of spreadsheet cells to the Windows Clipboard using Excel. Symptoms may include corruption of your display and many error messages from xcrt, although you probably will not see the messages unless you start your SCO Merge session from an xterm window.

These memory problems are more likely to happen on an X terminal, which typically has a more limited amount of memory. If they happen often with activities you typically perform, you should add more memory to your X terminal. You can also run zoomed or full-screen on the console.

To minimize occurrences of this problem when adding memory is not an option, you should avoid running PowerPoint's Quick Preview completely. When you plan to copy large amounts of data to the Windows Clipboard, turning off the X Cut & Paste option helps. If you are running out of memory on a workstation running the X server, starting your Windows session under SCO Merge with less memory may help by freeing memory for the X server.

Icons may be upside down on some X servers

On some X servers, the Windows icons may be upside down or corrupted. This can usually be corrected by making Windows re create the icons. Do this by right clicking on the Windows desk top and selecting a different display size. As soon as you complete this, change it back to the desired size. Windows will have rebuilt the icons and the problem should be resolved.

Changing to a different X server may cause the problem to come back. In which case the fix must be applied again.

Exiting Works for DOS or Word for DOS

When you run Word 6.0 for DOS or Works 2.0 for DOS on the Desktop and your display type is set to VGA, you must zoom to exit these programs. Zooming is required because these applications put the display into 640x350, 16-color graphics mode on exit. You can avoid the problem by starting your DOS session with the display type set to CGA.

WinG-based Windows games

When you run Windows on the Desktop on a 256-color display with the SCO Merge colormap feature turned on, WinG-based games do not work correctly. You can avoid most problems by running Windows with the colormap feature turned off; however, this workaround cannot be used for games that require a palettized display.

Colormap problems

If you start Windows under X with the colormap option on and a Windows application attempts to change the colormap, you may get strange colors and unreadable text.

Windows screen savers

Running animated Windows screen savers on the Desktop can consume significant amounts of CPU time. In particular, the Flying Windows screen saver uses most, if not all, of the available CPU time.

For this reason, we recommend:

• Use the X screen saver instead of animated Windows screen savers when you are running on the Desktop.

• If you must use a Windows screen saver, use the Blank Screen screen saver.

• If you must use an animated Windows screen saver such as the Flying Windows screen saver, tune it down to the lowest possible settings.

Netscape and 256-color displays

When you run Netscape on the Desktop on a 256-color display without the colormap feature turned on, Netscape does not display bitmaps properly. To avoid this problem, run your Windows session on the Desktop with the Use Private Colormap option turned on or change the X server to use a different number of colors. Netscape works properly on the Desktop when the X server uses 16 colors or 65,536 or more colors.

See ``Setting colors'' in Chapter 4 of the SCO Merge User's Guide for more information on the Use Private Colormap option.

WinFax Pro toolbar

When you run WinFax Pro on the Desktop, the toolbar buttons refresh very slowly. If you are using the console, you can avoid this problem by running full screen.

Cut & paste in FrameMaker

If you have a SCO Merge window and a FrameMaker window running at the same time, and you attempt to cut-and-paste a graphic or a table within FrameMaker, the FrameMaker session may fail.

To avoid this problem, define the following X resource:

	Maker.unifyClipboards: False

This turns off cut-and-paste functionality between FrameMaker and other applications. You can still use cut-and-paste within FrameMaker.

PowerPoint Quick Preview

When you run Microsoft PowerPoint 4.0 under Windows on the Desktop and use the Quick Preview function to look at multiple slides, PowerPoint may fail. Quick Preview creates pixmaps in the X server's memory, causing the X server to run out of memory. Therefore, we recommend that you not run Quick Preview under SCO Merge on the Desktop.

<Alt><Print Screen> limitation

On a UnixWare console, if you are running Windows either full screen or on the Desktop, the <Alt><Print Screen> key sequence does not work. To avoid this problem, press the <Print Screen/SysReq> key twice while holding down the <Alt> key.

Virtual memory and 32-bit (Win32s) applications

You must enable virtual memory in Windows 3.1 to use 32-bit applications, such as Win32s applications, including the following:

• Mathcad 5.0, Windows edition
• Claris Works 2.0
• FrameMaker 5.0, Windows edition

Using virtual memory on a Windows 3.1 system running in enhanced mode allows you to have more virtual memory than is physically installed. Under SCO Merge, you can have more virtual memory than you specify when you start the DOS or Windows session. However, because the UNIX system provides virtual memory more efficiently, we recommend not using Windows 3.1 virtual memory unless you specifically need to use it. If you need more memory for your Windows application, start your Windows session with more standard memory. (See ``Using virtual memory in Windows 3.1'' in Chapter 4 of the SCO Merge User's Guide.)

Win32s support

SCO Merge supports most versions of Win32s. As of this release, the newest supported version of Win32s is 1.30.172.

Saving Windows Recorder files

When you save a Recorder macro, Windows Recorder writes a temporary file in the root of the drive on which you are saving the macro file. If you do not have permission to write in the root directory of that drive (for example, on shared drive J), the save fails with this message:

    Cannot create the filename file.
    Make sure the path and filename are correct, or if
    you are using a network, that you can write to it.

Microsoft Antivirus Program - msav and mwav

MS-DOS 6.2x comes with two antivirus programs: a DOS program called msav and a Windows program called mwav. Under SCO Merge, both programs have problems scanning disks.

msav can only be used to check floppy disks. It does not work properly on UNIX drives.

mwav works well except in the following instances:

• If you have a drive configured to refer to the entire UNIX file system, mwav fails to scan it, usually hanging or killing your Windows session. To prevent this, do not create drives that provide access to the entire UNIX file system.

• If you have configured UNIX drives as local, mwav reports them as having 0 files. (You set drives to local or remote by running the merge command. For example, merge set drive local).

  To use mwav to scan these drives, change the drive's setting to remote as follows:

  	merge set drive remote
  

  (Note that the merge set drive command changes the setting for all UNIX drives at the same time.)

Reliability of WinFax and other communications programs

Under some conditions, WinFax or other communications or FAX programs may fail to receive a FAX or data file. This problem is more likely to occur if the system has a 486/33 or slower processor and is under heavy load when the receive operation is taking place. In addition, the problem can be worse if the COM port that the modem is using does not have a built-in FIFO (first-in-first-out queue, available on NS16550-class COM ports).

To avoid this problem, minimize your system load during receive operations. If you have an 8250 or 16450 COM port (that is, a COM port that does not have a FIFO queue), you can install a newer COM port with FIFO capabilities, such as a 16550.

IMODEM limitations with Procomm Plus

The IMODEM file transfer protocol available with Procomm Plus for DOS is not reliable and should not be used with SCO Merge. The problems occur because IMODEM is a streaming protocol and has no built-in flow control. Using this protocol, the computer sending the file can transmit data faster than the DOS process under SCO Merge can receive it, and the file transfer fails. Instead of IMODEM, use a reliable protocol such as XMODEM, ZMODEM, or KERMIT.

Microsoft Diagnostics - MSD

If you run MSD and select the option to display drive information, MSD does not properly display the free space for the C drive. If you are running MS-DOS 6.22, the C drive is incorrectly displayed as a RAM drive.

GP faults with Windows applications

Many Windows applications can cause GP faults under Windows 3.1 if Windows is low on memory. For example, with Lotus 1-2-3 or Freelance, a GP fault is likely to occur anytime the available memory drops below 2600 KB. To determine how much free memory is available at any time, bring up the About dialog box from the Program Manager's Help menu.

Using CorelDraw's CorelShow

Viewing the slide presentation in CorelDraw 5 CorelShow on the Desktop results in a corrupted screen. To use the slide view function, run SCO Merge in full-screen mode.

Using Save As in FoxPro

If you use the Save As option to save files under different names too often, FoxPro prints the error message:

        Too many files open

Using Find File in Word for Windows

Each time you select the Find File option from the File menu, and then use the Search dialog box to select both the Include Subdirectories and Rebuild File List options, Word for Windows opens several files that it never closes. If this action causes you to exceed the open file limit, exit Word for Windows and restart it.

Browsing large drives in Paradox

When you browse a very large drive (such as from the root of the UNIX file system), Paradox opens one file for each directory it finds. If you exceed the open file limit, Paradox silently fails to find any remaining directories and files. Closing the browser closes the open files.

WordPerfect's Directory Tree

If you use WordPerfect's Directory Tree feature (File -> Open -> File_Manager -> Specify_File_Manager -> Directory_Tree) to look at a very large drive (such as the UNIX file system), WordPerfect may kill the session if the open file limit is exceeded. This is a symptom of the UNIX file system limit on open files. The only solution is to increase the MERGE_MAXOPEN value.

Looking at very large drives with WordPerfect's Directory Tree is not normally recommended because it can take a very long time.

Using Find File with Microsoft Office

The Find File feature of Microsoft Office uses up open file resources extremely quickly. When you reach the open file limit, finding additional files or opening new files may fail until you exit Office. We recommend that you avoid using the Office Find File feature or, if you must use it, search only a limited number of directories and periodically exit and restart Office to close the open files.

Extended memory managers

mrgxms.sys is the only extended memory manager that you can use with SCO Merge. Do not use himem.sys, xms.sys, or any other DOS extended memory manager produced by other vendors.

For more information on using extended memory managers, see ``Maximizing conventional memory for DOS'' in Chapter 4 of the SCO Merge User's Guide.

Increasing record-locking table sizes

A Windows sharing violation can occur if SCO Merge runs out of internal record-locking table space. SCO Merge attempts to warn you with a message indicating whether the File Table, the Open-File Table, or the Lock Table has run out of space.

To increase the table size:

1. Log in to the UNIX system as root.
2. Edit the file /etc/default/merge, increasing the value of the parameter that corresponds to the table that is out of space (the parameter named in the error message). The table types, their parameter names, and their default values are:

     Table Type        Parameter Name                   Default Value
     ----------        --------------                   -------------
     File Table        MERGE_RLOCK_FILETABLE_SIZE       512
     Open-File Table   MERGE_RLOCK_OPENTABLE_SIZE       768
     Lock Table        MERGE_RLOCK_LOCKTABLE_SIZE       1024
   

   Doubling the existing value for the table that is out of space is generally more than sufficient.

3. Reboot the system.

File locking with NFS

The ability to take advantage of UNIX record locking when users and their DOS and Windows applications access shared files and databases is an important feature of SCO Merge.

However, it is turned off by default because file performance can be significantly slower when UNIX record locks are applied in an environment in which files are accessed and opened through NFS.

If file sharing is a concern, you should create separate drives for those portions of the UNIX file system that need to be shared and turn on the Unix Locking option through the Merge Setup utility.

DOS and Windows programs can perform file locking operations (called high locks) that are not supported over NFS. SCO Merge provides a workaround, which involves creating and using hidden directories (.lock_pci) in the directories where the files are being locked.

You can turn off the use of this workaround by setting a MERGE_AUTOCREATE_LOCKDIR variable to OFF in your UNIX environment or in the /etc/default/merge file.)

You can also create the hidden directories yourself as needed. If a .lock_pci subdirectory exists in a directory, it is used regardless of the setting of the MERGE_AUTOCREATE_LOCKDIR environment variable. The variable only governs automatic creation when a directory does not already exist.

File locking with LAN managers

You should avoid using SCO Merge, either locally or through NFS, to access files that other users are accessing through LAN Manager Client File System (LMCFS) and especially in conjunction with the Advanced File and Print Server (AFPS). File locking in this situation is not reliable.

NetWare support under SCO Merge

Most of the basic Novell NetWare 3.1x text utilities and commands are supported under SCO Merge, including the menu, pconsole, fconsole, syscon, printdef, printcon, and filer utilities and the userlist, atotal, whoami, flag, rights, and grants commands.

NetWare security is provided by the server, and no security violations are introduced by the lccipx.exe utility, which emulates the service supported by ipx.exe.

The following drivers (and versions) are supported:

	netx.exe	3.32
	vipx.386	1.11
	vnetware.386	2.04
	nwpopup.exe	2.00
	netware.drv	2.00

NetWare configuration

When you load netx (for example, in an autoexec.bat file) but do not install NetWare as the Windows network, DOS sessions started from Windows in enhanced mode do not work properly. They may fail to start, may cause a GP fault, or may start with a corrupted environment.

When you load netx, you must install NetWare as the Windows network even if you do not intend to access any NetWare drives from Windows.

When you install NetWare as the Windows network, you cannot use the DOS Merge Network Printing driver. (See ``The DOS Merge network printing driver'' in Chapter 2 of the SCO Merge User's Guide for more information.) In many cases, printing from Windows works fine without this driver. However, if you need to use the DOS Merge Network Printing driver, do one of the following:

• Do not load netx.
• Do not start DOS sessions from Windows.
• Run Windows in standard mode.

NetWare SPX limitation

Under NetWare 3.11, selecting the Print Server Status menu item from pconsole gives the following error message:

    Error PSATTACHTOPRINTSERVER returned error 65

Likewise, issuing the nver command gives a warning when it attempts to report the SPX version number of lccipx.exe.

NetWare and Microsoft Office

Microsoft Office will not install on a NetWare file system under SCO Merge. You must install Office on the UNIX file system.

Novell NetWare and PATH corruption

When you attach to a Novell NetWare 4.0.x server, the J drive path components (J:\dos and J:\merge) are removed from the PATH environment variable. This only happens on a 4.0.x server. Attaching to other versions of the Novell NetWare server does not cause this problem.

Limitations on wsupdate command

Do not use the /L option with the wsupdate command. This option can cause your SCO Merge session to hang.

When you choose to restart Windows either by using the Shut Down menu or after changing some configuration setting that requires restarting Windows, SCO Merge simply shuts down your session. You then need to restart Windows manually.

Using Acrobat Reader 3 from the Desktop

If you use the 16-bit version of Acrobat Reader 3.01 or any version of Acrobat Reader 3.0 in an X window on the Desktop, some color text may not be displayed properly.

To avoid this problem, use this application in full screen mode. To use full screen mode, make sure that Windows is installed with a VGA display driver. You can then start Windows either in the non-Desktop environment by typing the win command, or by invoking the Win utility in a Desktop environment and then zooming to full screen.

Alternatively, you can use the 32-bit version of Acrobat 3.01 in an X window, which does not exhibit the same problems.

Dr. Solomon does not work under SCO Merge

SCO Merge does not support installing or running Dr. Solomon under Windows.

Installing this application causes a special VxD to be configured such that the Windows session hangs every time it is started.

Problems with WordPad under Windows 95

WordPad under Windows 95 exhibits the following problem:

• WordPad does not properly display Write files (with extension .wri). The text in these files appears corrupted in some places which correspond to formatting instructions.

Normally, when a DOS or a Windows session (using the VGA display driver) switches into graphics mode while running in an X window, you will see a message telling you to zoom your session to full screen in order to continue.

Sometimes, SCO Merge does not detect that your session has switched into graphics mode, and the "need to zoom" message is not displayed while your session is suspended.

If your session hangs, and you suspect that it has changed the video mode (e.g. starting Windows from the Desktop opens a new window and then hangs), try zooming this session by selecting the Zoom option from the Window menu.

Unreliability of Internet Explorer support

Most versions of Microsoft Internet Explorer are unreliable under SCO Merge. Consequently, we recommend that you use Netscape Navigator as your Internet browser.

The following problems with Internet Explorer currently exist:

• Internet Explorer v. 3.02a (16-bit) and 3.03 (16-bit) fail with a message "Can't access the HTTP server". Internet Explorer v. 3.02 (32-bit) does not have this problem.

• News reader fails under Internet Explorer v. 3.01m (32-bit).

• Internet Explorer v. 4.0 fails to install under SCO Merge.

If you are running Windows 3.1 in an X window on a 32K-color X server, starting Paintbrush results in a general protection fault.

To work around this problem, run Windows in full screen mode by installing a VGA display driver instead of the Windows/X driver.

Using Windows 3.1 after SCO Merge upgrade

If you upgrade SCO Merge from a previous version, the following problems occur when running Windows 3.1:

• Some settings in your standard personal Windows session configuration are overwritten. If you modified your Windows session configuration and would like to keep those settings after an upgrade, make sure the configuration is correct before starting Windows.

• If you start a DOS session under Windows, you cannot exit it without killing the whole Windows session. To work around this problem, you will have to reinstall Windows.

Winstone 98 is not supported under SCO Merge.

The Winstone 97 high-end test suite is not supported under SCO Merge.

If you try running it, most applications will either hang the Windows session or generate a general protection fault. Also, copying the high-end test suite to the hard disk hangs your Windows session.

Other Windows 97 test suites are supported.

Problems running Netscape Navigator 4

The following problems have been observed while running Netscape Navigator under SCO Merge:

• Running the 16-bit version of Netscape Navigator 4.03, and trying to view the source for the current page (by selecting Page Source from the View menu), sometimes results in the Windows session crashing with a message:

          VM_DIED: dos: ERROR: The VM86 session died.
  

• When using the 32-bit version Netscape 4.01, WEB page background patterns are sometimes corrupted when you scroll through the page.

If you use Corel Presentation 7 to create a slide show, and then try to play it while running Windows in an X window, the window turns black until you click through all the slides in your presentation.

To work around this problem, play the slide show while running Windows in full screen mode. To do this, you need to install the VGA display driver under Windows.

Printing under Windows 95

When you set up a printer under Windows 95 using the Add Printer Wizard and then attempt to print for the first time, printing fails with the following error message:

There was an error writing to printer name

This happens when you print a test page from the Add Printer Wizard, or if you bypassed printing the test page, the first time you actually print a document. Printing works correctly after the first time.

Assertion failures using Word Internet Toolbar

If you install Internet Explorer that comes with Office 97 and make it your default web browser, using the Internet Toolbar from Word to open a URL may result in several "blue screens" with the message "PCIFSD: ASSERT FAILED". You can continue past these screens and establish a connection.

To avoid this problem, check the open in new window box when you specify the URL.