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Conference bulova::decw_jan-89_to_nov-90

Title:DECWINDOWS 26-JAN-89 to 29-NOV-90
Notice:See 1639.0 for VMS V5.3 kit; 2043.0 for 5.4 IFT kit
Moderator:STAR::VATNE
Created:Mon Oct 30 1989
Last Modified:Mon Dec 31 1990
Last Successful Update:Fri Jun 06 1997
Number of topics:3726
Total number of notes:19516

2189.0. "Client/Server question" by INFACT::DATZMAN (Indianapolis Field Applications Center) Fri Feb 02 1990 12:49

    Consider this:
    
    I have a DECwindows application that runs on a VAX 9000 and the display
    is redirected to a VS 3100.  If my application on the 9000 displays
    a color image (I am using the IDS$WIDGET_DEMO program from the DECimage
    product), what is actually being transferred over DECnet to the VS
    3100?  The VS3100 is a standalone node on the Ethernet.
    
    Is the whole image being sent over the net to the server or what?
    
    Thanks
    
    Dick
T.RTitleUserPersonal
Name		DateLines
2189.1PSW::WINALSKICareful with that VAX, EugeneFri Feb 02 1990 18:345
If the image is an array of pixel values, then the whole image is being
transferred over the net to the server 3100 system.  How could it be otherwise?
The client application that generates the data is on the 9000.

--PSW
2189.2What about X terminals?INFACT::DATZMANIndianapolis Field Applications CenterSat Feb 03 1990 18:205
    OK, that makes sense.  Now, how much more work, if any, is the 9000
    going to do if the server is not a workstation but an X terminal ala
    VT1000?
    
    Dick
2189.3No DifferencesCADSYS::SLATERTomorrow, you can be anywhere...Sun Feb 04 1990 09:1926
>    OK, that makes sense.  Now, how much more work, if any, is the 9000
>    going to do if the server is not a workstation but an X terminal ala
>    VT1000?
    
    Essentialy no difference - an X server is an X server, and the client
    on the 9000 can't tell the difference no matter if it is a high end
    VAXstation or a low end X terminal. The same information goes out
    over the "wire".

    Looking closer, there are minor differences. The first is server
    cababilities in terms of screen size (pixels in x and y) and depth
    (number of planes (colors or shades of gray)). If your IDS Image
    Widget client on the 9000 has to dither a color image to use fewer
    colors because your server can't support as many as you VAXstation,
    then the client has to do more work (I understand our future X terminal
    will not support color in the first version).

    Also, there may be minor differnces in packaging the information for
    transport, which for your purposes are probably negligable. Currently
    we support Local, DECnet and TCP/IP transports, and the future X
    terminal will support another. The information remains the same, the
    packets it is transported in (the envolope) my vary slightly.

    But again, basically, the client does the same work to provide
    information to display on the the X Server, pretty much independent of
    the nature of the X server...Ken