Precedence Network Computer and NetManager
Displays/Graphics

  1. How do I alter the screen mode (e.g. colour depth) on the NCs

    Edit the file !NFSBoot.Custom.AllNCs.!Run and alter the line that says Set Screen$Mode to contain details of the mode. This should be one of: In addition, you may put the letter "f" on the line to force a higher refresh rate (i.e. 75Hz vs 60Hz). An example line is "x800 y600 c256 f". N.B. The 75Hz refresh-rate is not a standard SVGA rate and so some displays will fail to show it (e.g. projectors, large screen TVs, some TFTs).

    If you want some of the NCs to use a different mode, then copy the AllNCs directory as the hostname of the NC (as reported when the NC boots up) into the same directory. You can then edit the Screen$Mode line for that particular NC. Make sure that the contents of the Custom directory are public read

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  2. How do I use an NC with a TV?

    You must have the monitor unplugged when using the composite video out, otherwise the NC will use the screen mode stored in CMOS by default (VGA or SVGA) which will not be suitable for TV use.

    You should also make sure that you have applied all the hotfixes as work has been done to make the integration of NCs with TVs even easier. The default mode on a TV is 768 x 576 (interlaced). This is an overscan mode with no borders which means that the picture will extend of the edges of the screen. Some applications are aware of this (notably NCFresco and NCWriter) and will adjust their displays accordingly. Most applications (including all RISCOS applications) are not aware and so anything at the extremes of the display may not be visible. Therefore, it is often better to run in 640 x 480 (interlaced) in which screen borders will be displayed. (For the historically minded, this is similar to the distinction between modes 12-15 and modes 33-36).

    If all the latest hotfixes have been applied (notably hotfix 166), the behaviour on a TV has been extended. Previously the value of the Screen$Mode variable described above was ignored. This has been altered so that you can specify a resolution to be used on a TV as well as a resolution to be used on a monitor. To activate this behaviour you need to put the letters tv in the ine that sets the Screen$Mode variable for that NC. If the letters tv are not present, the default mode on an NC will be 640x480 (was 768x576 prior to hotfix 166). After the letters tv, you can specify another resolution in the same way as the first. For example:

    1. Set Screen$Mode x800 y600 c256
      Monitor: 800x600 (256 colours)
      TV: 640x480 (256 colours)
    2. Set Screen$Mode x640 y480 c32k
      Monitor: 640x480 (32000 colours)
      TV: 640x480 (32000 colours)
    3. Set Screen$Mode x800 y600 c256 tv
      Monitor: 800x600 (256 colours)
      TV: Attempt 800x600 (256 colours) will fail as TV is not capable of that resolution and so NC will stay in the default 768x576 (32000 colours)
    4. Set Screen$Mode x800 y600 c256 tv x640 y480 c32k
      Monitor: 800x600 (256 colours)
      TV: Attempt 640x480 (32000 colours)
    5. Set Screen$Mode x800 y600 c256 tv x640 y256 c256
      Monitor: 800x600 (256 colours)
      TV: Attempt 640x256 (256 colours). N.B. This is non-interlaced and will not flicker

    The display on a TV will be clear, but will be flickery in all applications besides NCFresco and NCWriter. This is due to the interlacing displaying horizontal lines only on every alternate frame (NCFresco and NCWriter use a technique called anti-twittering to reduce this). By choosing a low resolution non-interlaced display such as in example 5), the display will not flicker (at the expense of a loss of resolution). Alternatively, to remove the flicker all together, you can purchase a PAL converter which plug in between the NC and a monitor and converts the signal to work on a TV. This will remove the flickering at the expense of making the display more blurred.

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  3. How do I get the NCs to blank the screen after a certain time?

    1. Log onto an NC as ncadmin
    2. Choose Edit the boot sequence
    3. Choose Click here to open the directory
    4. Shift double-click on !NFSBoot
    5. Shift double-click on PreDesktop
    6. In the window, go down until you see a line that reads: 
      %Configure WimpAutoMenuDelay 30
    7. Add the following line to the file: 
      BlankTime 300
      Replace 300 by your chosen delay for blanking in seconds if you wish
    8. Save the file

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