PEPP VNC Usage Tips

This page gives you more information about a few details of running VNC to display real-time seismic data.  It provides a few tips peculiar to this setup that are not found in the standard VNC documentation.

Display colors:

You may encounter display inconsistencies that could cause some antelope applications to crash.  The problem is that most older computers used "8 bit" color displays while newer hardware will commonly use "full color = 24 bit" displays.  Currently some antelope applications don't handle this cleanly and may not start up.  If you have this problem and have a 24 bit display you should try starting the vncserver using the "-depth" arguments:

vncserver -depth 24 -alwaysshared -dontdisconnect

which enables "full color" mode.  If that doesn't work, the best advise is to experiment with changing the settings on the display on your local machine and try to find a permutation that works.

Connection Speed:

We have successfully used vnc to display real-time data on a modem with as little as 22.8 kbaud speed.  It can, however, be painful at this minimal rate.  The best advise if you have a slow speed connection is to try not to do anything too interactive, but just leave the display running and be patient if you need to interact with the display.  On a slow display you will most notice that the mouse may not directly track the original screen pointer, but shows a small dot instead.  This is a vnc feature used to minimize display updates, but it can be confusing.

Interacting with X window objects:

The real-time display you are viewing in this procedure is based on a package called X windows.  You are basically displaying windows from one window system on another.  This means the windows have a distinct hierarchy you must keep in mind.  That is, window inside the vnc viewer window are controlled by the vncserver while those outside that window are controlled by your local window manager.  This can be confusing because you may find point/click interactions are slightly different between the two systems.


First some definitions.

mb1 = "mouse button 1"  = left mouse button
mb3 = "mouse button 3" = right mouse button on a 2 or 3 button mouse.
hold = means hold down button and release (e.g. mb1/hold means point, hold down mb1, and drag as desired, then release)
click = click on a feature

Now some basic X windows manipulations:

1.  The top bar on a window is special in this window manager.   If you position the mouse pointer over the top bar of a window the following can be done:

mb1/click will bring the window to the front
mb1/hold can be used to move a window to a different position on the display

2.  To resize a window position the mouse pointer over any corner of the window and wait for the cursor symbol to change to a circle.  Then use mb1/hold to resize the window.

3.  Most, but not all, menu's are accessed by pointing the cursor at the entry (e.g. File in orbmonrtd) and using mb1 like most window managers today.  A detail is that some menus pop up on a click and stay while others require a hold/drag operation, but we assume most people know how to handle this type of annoying variation.  

4.  mb3/click on the top bar of a window will bring up a menu that controls that window's visibility.  You will find an entry there to close down the window.  This is a non elegant way to kill a process if you can't grab the quit menu for some reason.

5.  You iconify a window by pointing at the small box in the upper right corner of a window and depressing mb1.

6.  To deiconify a window, double click the icon on the desktop.