Document revision date: 10 November 2000

Some default characteristics of the keyboard attached to the server system can be modified. These include keyboard operations, such as keyclick and bell volume and autorepeat, as well as how the keyboard keys are mapped to keyboard independent symbols used by client applications.

All of the keyboard settings in this section are overriden by the Session Manager. Setting these symbols takes effect before the user logs in or if you are not using DECwindows Session Manager.

DECW$DEFAULT_KEYBOARD_MAP

You can specify the language for which your keyboard is designed.

Valid values for DECW$DEFAULT_KEYBOARD_MAP are the file names (without file type) in the SYS$COMMON:[SYS$KEYMAP.DECW.SYSTEM] and SYS$COMMON:[SYS$KEYMAP.DECW.USER] directories.

The following symbol definition changes the keyboard layout to a Dutch typewriter layout:

Example

$ DECW$DEFAULT_KEYBOARD_MAP == "DUTCH_LK201LH_TW"
      

For a list of keymap names, see Table B-1.

DECW$SERVER_BELL_BASE_VOLUME

This parameter determines the volume of the bell sound in a keyboard. Values are from 0 to 100, with 100 being the loudest. The default volume level is 50.

The following logical definition sets the volume to one quarter of full volume:

Example

$ DEFINE/SYSTEM DECW$SERVER_BELL_BASE_VOLUME 25
      

DECW$SERVER_KEYCLICK_VOLUME

This parameter determines the volume of the click sound in a keyboard. Values are from 0 to 100, with 100 being the loudest. The default is 0.

The following symbol definition sets the volume to one quarter of full volume.

Example

$ DEFINE/SYSTEM DECW$SERVER_KEYCLICK_VOLUME 25
      

DECW$SERVER_ENABLE_KB_AUTOREPEAT

Keyboard autorepeat is an option that causes a character to repeat itself automatically while that character key is pressed. You can enable this option by specifying True for this parameter.

The following logical definition enables keyboard autorepeating of typed characters:

Example

$ DEFINE/SYSTEM DECW$SERVER_ENABLE_KB_AUTOREPEAT T
      

DECW$SERVER_MAIN_KB_UPDOWN (VAX Only)
<vax_ps_section> <vax_br_section>

On VAX systems, this parameter defines whether the server receives reports of the down and up movements made by pressing the main keyboard keys. When set to False, the keyboard driver reports a key release immediately after any main keyboard key is pressed. When set to True, key releases are not reported until a key is physically released.

The following logical definition causes main keyboard key presses to be reported to the server:

Example

$ DEFINE/SYSTEM DECW$SERVER_MAIN_KB_UPDOWN T<endsection>
      

Use the symbols in this section to modify mouse pointer characteristics. All the mouse pointer settings in this section are overriden by Session Manager. Setting these symbols takes effect before the user logs in or if you are not using DECwindows Session Manager.

DECW$SERVER_MOUSE_ACCELERATION

This parameter defines the relationship of mouse movement to pointer movement. The possible values are as follows:

2 (fast)
1 (medium)
0 (slow)

The following logical definition causes the pointer to move at the fast speed in relation to your mouse movements.

Example

$ DEFINE/SYSTEM DECW$SERVER_MOUSE_ACCELERATION 2
      

DECW$SERVER_MOUSE_THRESHOLD

This parameter defines the minimum motion of the mouse (in pixels) at which time the DECwindows server is notified of the motion. The default is 4 pixels.

The following logical definition causes the mouse to be very sensitive to movement, resulting in the report of movement to the DECwindows server.

Example

$ DEFINE/SYSTEM DECW$SERVER_MOUSE_THRESHOLD 1
      

The display server uses a color database file to translate color names passed to the server from client applications into RGB values. Use the symbols in this section to modify color database characteristics.

DECW$RGBPATH

This parameter defines the RGB database file-name to be used with the server. The default name is SYS$MANAGER:DECW$RGB.DAT:

The following symbol definition changes the file name value to DECW$RGBPATH.DAT.

Example

$ DECW$RGBPATH == "SYS$MANAGER:DECW$NEWRGB.DAT"
      

The Screen Saver feature causes the monitor to go blank after a specified length of time (10 minutes by default) during which no user input occurs. Note that the actual value is specified in seconds.

Optionally, the server displays a black or white X of a random size and location on the screen when the screen saver timeout expires. A second parameter specifies the interval after which the Screen Saver pattern is repainted. This Screen Saver is not recommended for normal use because the screen background remains visible.

DECW$SERVER_SCREEN_SAVER_PREFER_BLANKING

This parameter determines the method by which Screen Saver is performed. When the value is True (the default), the DECwindows server causes the video device driver to turn off the video signal when the Screen Saver timeout expires. When the value is False, the DECwindows server blanks the screen when the timeout expires.

The following logical definition causes the screen to be cleared when the Screen Saver timeout expires.

Example

$ DEFINE/SYSTEM DECW$SERVER_SCREEN_SAVER_PREFER_BLANKING F
      

DECW$SERVER_SCREEN_SAVER_TIMEOUT

This parameter defines the initial time (in seconds) before the screen saver is activated, after which the screen saver interval takes effect. The default is 600 seconds (10 minutes).

The following logical definition causes the initial screen saver time to be 1200 seconds(20 minutes):

Example

$ DEFINE/SYSTEM DECW$SERVER_SCREEN_SAVER_TIMEOUT 1200
      

DECW$SERVER_SCREEN_SAVER_INTERVAL

This parameter defines the number of minutes the server waits before repainting the screen background. The Screen Saver option rearranges the screen pixels after 10 minutes to avoid burning the screen phosphor. Some servers use nonblanking screen savers, such as swimming fish or logos. The default is 600 seconds.

The following logical definition causes the background screen to be repainted in 420-second (7-minute) intervals:

Example

$ DEFINE/SYSTEM DECW$SERVER_SCREEN_SAVER_INTERVAL 420
      

In general, it is the responsibility of the client application to restore occluded regions of the screen once they are exposed. However, the display server has several techniques available to perform this operation on behalf of the client. These are the backing store and save under options.

Backing store saves portions of windows in server memory just before they are obscured. Later, when the portions are exposed, the server can repaint them without involving the client. This can drastically reduce the time required to repaint, particularly for windows containing complex graphics or for environments where the client/server link is slow.

Save under is a similar mechanism where just prior to painting a window, the server saves the portion of the screen that is about to be obscured.

Both of these mechanisms are available by default and can be set on a window-by-window basis. Heavy use of these mechanisms does increase the memory requirements of the server. You may want to disable these features when debugging client applications to ensure that the application handles all expose events properly.

DECW$SERVER_DEFAULT_BACKING_STORE

You can enable this option in three types of window states. The following table lists possible values for the symbol and their meanings:

Value	Meaning
2	Enable backing store at all times
1	Enable backing store only when window is mapped
0	Indeterminate; depends on the server and the device being used

The value for DECW$SERVER_DEFAULT_BACKING_STORE can be overridden in applications on a per-window basis.

A True value for DECW$SERVER_DISABLE_BACKING_STORE causes the backing store option not to be used.

The following logical definition causes the server to save and restore windows when the windows are mapped to the screen.

Example

$ DEFINE/SYSTEM DECW$SERVER_DEFAULT_BACKING_STORE 1  
      

DECW$SERVER_DISABLE_BACKING_STORE

Use this parameter to disable backing store support. The default value is False so that backing store is enabled by default.

When DECW$SERVER_DISABLE_BACKING_STORE is set to True (disable backing store), restart the server, at which time the backing store option is disabled. Thereafter, to reenable backing store, deassign or redefine DECW$SERVER_DISABLE_BACKING_STORE and restart the server.

If your application window comes up blank, then the application is incorrectly requesting backing store but is also waiting for an expose event to begin processing. Either modify your application so that it does not request backing store, or set DECW$SERVER_DISABLE_BACKING_STORE to True and restart the DECwindows server.

The following symbol definition disables backing store:

Example

$ DECW$SERVER_DISABLE_BACKING_STORE == "T"  
      

DECW$SERVER_DISABLE_SAVE_UNDER

The save under option records window information that may be hidden when another window is placed on top. You can disable this option by specifying True for this parameter.

The save under option is similar to the backing store option, but only the occluded portions of windows are saved by the server so that when that portion of the window becomes visible, the server redraws that portion of the window.

The following symbol definition disables the server's save under option:

Example

$ DEFINE/SYSTEM DECW$SERVER_DISABLE_SAVE_UNDER T
      

The display server creates a log file into which it writes informational and error messages to aid in troubleshooting problems. The log file is called SYS$MANAGER:DECW$SERVER_n_ERROR.LOG, where n is the server number (usually 0).

The display server uses a condition handler to trap error conditions (such as an access violation) that might otherwise cause the display server to stop. If the condition handler detects a nonfatal error, it tries to allow the display server to continue. The condition handler always records the error in the error log file. If the condition handler detects errors for a single client (2 by default), it disconnects the client.

When the condition handler recovers from an error, the display server may lose track of some resources, such as memory. Therefore, after a number of these exceptions (10 by default), the condition handler broadcasts a message to all users on the workstation indicating that the display server may be running in a degraded mode and suggests that the display server should be restarted. If you see a message like this, restart the display server at the next convenient opportunity. See Section 2.2.1 for instructions for restarting the server.

DECW$SERVER_BUG_COMPATIBILITY

Inconsistencies between pre--X11 R4 servers and the X11 protocol allowed some undefined bits to be set in some X requests. By strictly enforcing this part of the protocol, however, some applications that set undefined bits no longer worked. By setting bug compatibility to True (default), the server will continue to allow these applications to work; however, the applications should be recoded to comply with the X11 protocol.

The following symbol definition allows pre--X11 R4 servers and X11 protocol applications to function correctly:

Example

$ DECW$SERVER_BUG_COMPATIBILITY == "T"
      

DECW$SERVER_DUMP

By setting this parameter to True, it adds the /DUMP qualifier to the DCL command RUN, which causes a process dump if the server crashes. Specifying True also automatically disables the server condition handler (sets DECW$SERVER_DISABLE_CH to True).

The following logical definition adds the /DUMP qualifier to the DCL command RUN and disables the server condition handler:

Example

$ DEFINE DECW$SERVER_DUMP T
      

DECW$SERVER_ERROR_LOG_TO_KEEP

This parameter defines the number of versions of the error log file to save. The default is two versions.

The following symbol definition causes the DECwindows server to save the three most recent versions of the error log file:

Example

$ DECW$SERVER_ERROR_LOG_TO_KEEP == "3"
      

DECW$CLIENT_ERROR_THRESHOLD

This parameter defines the number of protocol errors generated by a single client above which the client will be terminated. The default is one protocol error.

The following logical definition causes the DECwindows server to terminate a client after 10 or more protocol errors have been generated:

Example

$ DEFINE/SYSTEM DECW$CLIENT_ERROR_THRESHOLD 10
      

DECW$SERVER_ERROR_THRESHOLD

This parameter defines the total number of server errors you allow (10 by default) before reporting the following message:

Server internal runtime error threshold exceeded (code = %x), server performance may be degraded.

The symbol %x is replaced by the condition code (in hexadecimal) that forced the error. The most typical value is "c", specifying an access violation.

The following message is also broadcast to all logged-in terminals:

DECW$SERVER_ERROR: internal runtime error threshold exceeded. Performance may be degraded, restart DECwindows software when convenient by @SYS$MANAGER:DECW$STARTUP RESTART.

After every five server errors that exceed the threshold, the following message is sent to the SYS$MANAGER:DECW$SERVER_0_ERROR.LOG log file and broadcast to terminals connected to the server:

Server performance still degrading...

Three categories of errors are handled by the condition handler of the server which are reported to the log file.

• Errors that count toward the client error threshold
  • If the error count is less than the client error threshold, the following error is reported:

    opcode %d is ignored due to internal runtime error %x for client %d (#error = %d)

  • If the error count equals or exceeds the client error threshold, the following error is reported:

    Client %d has made too many runtime errors (%d), its connection is marked for termination

• Errors that disconnect a client

  Client %d has been disconnected due to unrecoverable runtime error %x detected while processing opcode %d

  
  Or, if the server is processing an opcode for a server extension, the following message is displayed:

  Exception trapped while processing extension opcode %d (extension id=%d)

• Errors that terminate the server

  Unrecoverable server internal error (error code = %d) found, terminating all connections. . . . List of active images and call chain at time of the error . . . ** SERVER INTERNAL RUNTIME ERROR ENCOUNTERED, SERVER HAS JUST CRASHED!! ** ********************************************

The following logical definition causes the DECwindows server to report a system degradation message after 20 server errors have accumulated:

Example

$ DEFINE/SYSTEM DECW$SERVER_ERROR_THRESHOLD 20
      

DECW$SERVER_CONNECT_LOG

This parameter specifies whether normal client connect/disconnect messages get logged to the server error log file. By default, all successful connect/disconnect messages are not logged, which results in an increase in server performance.

The following symbol definition causes the server to record client connect/disconnect messages in the SYS$MANAGER:DECW$SERVER_0_ERROR.LOG server error log file.

Example

$ DECW$SERVER_CONNECT_LOG == "T"
      

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