VerticalRefresh on LCD, does it exist? - Hardware

This is a discussion on VerticalRefresh on LCD, does it exist? - Hardware ; I have read this monitor-specifics. Horizontal Refresh (kHz) Vertical Refresh (Hz, only cathode-ray tube) Can someone explain that strange declaration?...

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  1. VerticalRefresh on LCD, does it exist?

    I have read this monitor-specifics.

    Horizontal Refresh (kHz)
    Vertical Refresh (Hz, only cathode-ray tube)

    Can someone explain that strange declaration?




  2. Re: VerticalRefresh on LCD, does it exist?

    toni wrote:
    > I have read this monitor-specifics.
    >
    > Horizontal Refresh (kHz)
    > Vertical Refresh (Hz, only cathode-ray tube)
    >
    > Can someone explain that strange declaration?


    The interface between the monitor and the PC, let it be VGA or DVI still
    transmit data "serially" and thus defines a vertical and horizontal
    refresh rate. For most LCDs the vertical refresh rate is 60Hz, though,
    some of them even re-sample the signal to 60Hz while others can
    synchronize to higher frequencies. Thus, playing with the vertical
    refresh rate on a digital monitor doesn't do very much. They don't
    flicker in first place...

    So long,
    Thomas

  3. Re: VerticalRefresh on LCD, does it exist?

    On 2007-07-01, Thomas Richter wrote:
    > toni wrote:
    >> I have read this monitor-specifics.
    >>
    >> Horizontal Refresh (kHz)
    >> Vertical Refresh (Hz, only cathode-ray tube)
    >>
    >> Can someone explain that strange declaration?

    >
    > The interface between the monitor and the PC, let it be VGA or DVI still
    > transmit data "serially" and thus defines a vertical and horizontal
    > refresh rate. For most LCDs the vertical refresh rate is 60Hz, though,
    > some of them even re-sample the signal to 60Hz while others can
    > synchronize to higher frequencies. Thus, playing with the vertical
    > refresh rate on a digital monitor doesn't do very much. They don't
    > flicker in first place...
    >
    > So long,
    > Thomas


    What about setting a resolution of the LCD to be different than the
    "native" mode? I've found that the setting of 1024x768 rather than
    1280x1024 will allow a vertical rate of 75 hz instead of only 60 hz
    in 1280x1024 mode. Is it a "real" vertical rate?

    Why a lower resolution? Because some of us no longer have as good
    eyesight when younger & the large monitors' have the text too small.

  4. Re: VerticalRefresh on LCD, does it exist?

    Hello,

    student a écrit :
    >
    > What about setting a resolution of the LCD to be different than the
    > "native" mode?


    It is usually considered a bad idea because it forces the monitor
    electronics to interpolate the picture to the LCD native resolution, and
    the quality result can be very poor. LCD monitors are intended to be
    used at their native resolution.

    > I've found that the setting of 1024x768 rather than
    > 1280x1024 will allow a vertical rate of 75 hz instead of only 60 hz
    > in 1280x1024 mode. Is it a "real" vertical rate?


    I don't know. Anyway a higher frequency won't have any benefit.

    > Why a lower resolution? Because some of us no longer have as good
    > eyesight when younger & the large monitors' have the text too small.


    A better solution is to increase the font size instead of decreasing the
    display resolution. Modern OSes allow it. Besides, displaying a 1024x768
    picture on a 1280x1024 native screen causes a vertical compression of
    the picture due to the different aspect ratios (Hres/Vres).

  5. Re: VerticalRefresh on LCD, does it exist?

    On Sun, 01 Jul 2007 11:11:23 -0500
    student wrote:

    > Why a lower resolution? Because some of us no longer have as good
    > eyesight when younger & the large monitors' have the text too small.


    In a correctly configured environment[1], changing the resolution will
    change the quality of the image, but won't change the size of windows,
    text and pictures. That's, lowering the resolution may make it harder
    to read the text.

    [1] At least this is my opinion:

    deschutes ~ # grep DisplaySize /etc/X11/xorg.conf
    DisplaySize 380 300

    But of course YMMV :-)



    --
    Nuno J. Silva
    Lisbon, Portugal
    Homepage:
    Registered Linux User #402207 - http://counter.li.org

    Using Claws Mail 2.9.2

    Gentoo Base System release 1.12.9
    Linux 2.6.17-gentoo-r7 i686 Pentium II (Deschutes)

    -=-=-
    Win95 is not a virus; a virus does something.
    -- unknown source

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  6. Re: VerticalRefresh on LCD, does it exist?

    On 2007-07-01, Pascal Hambourg wrote:
    > Hello,
    >
    > student a écrit :
    >>
    >> What about setting a resolution of the LCD to be different than the
    >> "native" mode?

    >
    > It is usually considered a bad idea because it forces the monitor
    > electronics to interpolate the picture to the LCD native resolution, and
    > the quality result can be very poor. LCD monitors are intended to be
    > used at their native resolution.
    >
    >> I've found that the setting of 1024x768 rather than
    >> 1280x1024 will allow a vertical rate of 75 hz instead of only 60 hz
    >> in 1280x1024 mode. Is it a "real" vertical rate?

    >
    > I don't know. Anyway a higher frequency won't have any benefit.
    >
    >> Why a lower resolution? Because some of us no longer have as good
    >> eyesight when younger & the large monitors' have the text too small.

    >
    > A better solution is to increase the font size instead of decreasing the
    > display resolution. Modern OSes allow it. Besides, displaying a 1024x768
    > picture on a 1280x1024 native screen causes a vertical compression of
    > the picture due to the different aspect ratios (Hres/Vres).


    Have been trying out the native resolution. X doesn't allow much
    changeing of fonts in various windows places or dialoges; firefox doesn't
    allow much font changing in the title/menu/selection; opera does more but
    still some boxes have a tiny text & some boxes/windows ignore the larger
    setting for the text.

    WinXP does better in general but still in some dialoges (e.g. display
    properties) are still in the "native" tiny faded (?) text size.

  7. Re: VerticalRefresh on LCD, does it exist?

    On Sun, 01 Jul 2007 14:58:34 -0500
    student wrote:

    > >> Why a lower resolution? Because some of us no longer have as good
    > >> eyesight when younger & the large monitors' have the text too
    > >> small.

    > >
    > > A better solution is to increase the font size instead of
    > > decreasing the display resolution. Modern OSes allow it. Besides,
    > > displaying a 1024x768 picture on a 1280x1024 native screen causes a
    > > vertical compression of the picture due to the different aspect
    > > ratios (Hres/Vres).

    >
    > Have been trying out the native resolution. X doesn't allow much
    > changeing of fonts in various windows places or dialoges; firefox
    > doesn't allow much font changing in the title/menu/selection; opera
    > does more but still some boxes have a tiny text & some boxes/windows
    > ignore the larger setting for the text.


    When you want a more generalized effect, you may want to play with the
    setting I mentioned in another post, telling X your screen is smaller
    than what it really is will make things bigger.

    The setting, in xorg.conf, is inside the monitor-related section,
    here's an example from my xorg.conf:

    Section "Monitor"
    #ViewSonic VA902 19'' 1280x1024
    Identifier "Monitor0"
    DisplaySize 380 300
    HorizSync 30.0 - 82.0
    VertRefresh 50.0 - 75.0
    Option "DPMS"
    EndSection

    The syntax is: DisplaySize width height
    Values are measured in millimetres.


    But in Firefox you will need to change a setting. Don't ask me why.

    Write about:config in the address bar, and write:

    If using Firefox 1.5: browser.display.screen_resolution


    If using Firefox 2.0: layout.css.dpi


    Then change the value to 0 if you want Firefox to use the X server dpi
    setting. -1 will use the X server one *or* 96, "whichever is greater".
    You may also enter the desired dpi directly here (positive values are
    used as dpi).

    You can always check the actual resolution (in dpi) and the dimensions
    using:
    xdpyinfo | grep resolution
    xdpyinfo | grep dimensions

    --
    Nuno J. Silva
    Lisbon, Portugal
    Homepage:
    Registered Linux User #402207 - http://counter.li.org

    Using Claws Mail 2.9.2

    Gentoo Base System release 1.12.9
    Linux 2.6.17-gentoo-r7 i686 Pentium II (Deschutes)

    -=-=-
    “As we enjoy great advantages from the inventions of others, we should
    be glad of an opportunity to serve others with any invention of ours,
    and this we should do freely and generously.” -- Benjamin Franklin

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  8. Re: VerticalRefresh on LCD, does it exist?

    On 2007-07-01, Nuno J. Silva wrote:
    > --Sig_gyYqHVuTBI2i.IK2SDg05lC
    > Content-Type: text/plain; charset=UTF-8
    > Content-Transfer-Encoding: quoted-printable
    >
    > On Sun, 01 Jul 2007 14:58:34 -0500
    > student wrote:
    >
    >> >> Why a lower resolution? Because some of us no longer have as good
    >> >> eyesight when younger & the large monitors' have the text too
    >> >> small. =20
    >> >
    >> > A better solution is to increase the font size instead of
    >> > decreasing the display resolution. Modern OSes allow it. Besides,
    >> > displaying a 1024x768 picture on a 1280x1024 native screen causes a
    >> > vertical compression of the picture due to the different aspect
    >> > ratios (Hres/Vres). =20

    >>=20
    >> Have been trying out the native resolution. X doesn't allow much
    >> changeing of fonts in various windows places or dialoges; firefox
    >> doesn't allow much font changing in the title/menu/selection; opera
    >> does more but still some boxes have a tiny text & some boxes/windows
    >> ignore the larger setting for the text.

    >
    > When you want a more generalized effect, you may want to play with the
    > setting I mentioned in another post, telling X your screen is smaller
    > than what it really is will make things bigger.
    >
    > The setting, in xorg.conf, is inside the monitor-related section,
    > here's an example from my xorg.conf:
    >
    > Section "Monitor"
    > #ViewSonic VA902 19'' 1280x1024
    > Identifier "Monitor0"
    > DisplaySize 380 300
    > HorizSync 30.0 - 82.0
    > VertRefresh 50.0 - 75.0
    > Option "DPMS"
    > EndSection
    >
    > The syntax is: DisplaySize width height
    > Values are measured in millimetres.
    >
    >
    > But in Firefox you will need to change a setting. Don't ask me why.
    >
    > Write about:config in the address bar, and write:
    >
    > If using Firefox 1.5: browser.display.screen_resolution
    >
    >
    > If using Firefox 2.0: layout.css.dpi
    >
    >
    > Then change the value to 0 if you want Firefox to use the X server dpi
    > setting. -1 will use the X server one *or* 96, "whichever is greater".
    > You may also enter the desired dpi directly here (positive values are
    > used as dpi).
    >
    > You can always check the actual resolution (in dpi) and the dimensions
    > using:
    > xdpyinfo | grep resolution
    > xdpyinfo | grep dimensions
    >
    > --=20
    > Nuno J. Silva
    > Lisbon, Portugal
    > Homepage:
    > Registered Linux User #402207 - http://counter.li.org
    >
    >

    Thanks, will try it.

    Now wondering if I should do something with the console mode
    as I boot into text mode & after mail & news, I go into
    X. Have been setting grub to go into 800x600.l


  9. Re: VerticalRefresh on LCD, does it exist?

    >> You can always check the actual resolution (in dpi) and the dimensions
    >> using:
    >> xdpyinfo | grep resolution
    >> xdpyinfo | grep dimensions


    I normally change the -dpi ### option that X starts with to increase font
    size. Granted that it doesn't work for all apps. The larger the dpi,
    the larger the fonts. There's various places to set it, depending on how
    you startx. startx -- -dpi 100. Or for kdm, it's in the /etc/kde3/kdm/
    kdmrc file. Recalling from memory, so don't quote me on it. It should
    be on the line that includes -nolisten tcp and whatever other options are
    passed to X when it starts.

    I also have multiple resolutions available in my modes. That way if I
    need to magnify, I just Cntrl+Alt+Keypad-Minus(or plus). A little
    trickier on laptops, Fn+Scroll, then Cntrl+Alt+[-]. Just don't forget to
    Fn+Scroll again when you want to type again. Not that my eyesight is all
    that bad yet, but sometimes when you first wake up in the morning, you
    need a little help.


  10. Re: VerticalRefresh on LCD, does it exist?

    On 2007-07-02, Shadow_7 wrote:
    >>> You can always check the actual resolution (in dpi) and the dimensions
    >>> using:
    >>> xdpyinfo | grep resolution
    >>> xdpyinfo | grep dimensions

    >
    > I normally change the -dpi ### option that X starts with to increase font
    > size. Granted that it doesn't work for all apps. The larger the dpi,
    > the larger the fonts. There's various places to set it, depending on how
    > you startx. startx -- -dpi 100. Or for kdm, it's in the /etc/kde3/kdm/
    > kdmrc file. Recalling from memory, so don't quote me on it. It should
    > be on the line that includes -nolisten tcp and whatever other options are
    > passed to X when it starts.
    >
    > I also have multiple resolutions available in my modes. That way if I
    > need to magnify, I just Cntrl+Alt+Keypad-Minus(or plus). A little
    > trickier on laptops, Fn+Scroll, then Cntrl+Alt+[-]. Just don't forget to
    > Fn+Scroll again when you want to type again. Not that my eyesight is all
    > that bad yet, but sometimes when you first wake up in the morning, you
    > need a little help.
    >

    Will check out startx parms; found that my xorg.conf is about the same
    as the other poster's conf; i.e. resolution is 382 302 with the
    DPMS option.

    Found that I can somewhat change some fonts (menu, menupopup, menuitem, etc
    using my userChrome.css. I do need to experiment more here as thought that
    "font size" is not the same as "font point" regarding 'sizes'.

  11. Re: VerticalRefresh on LCD, does it exist?

    Pascal Hambourg wrote:

    > Hello,
    >
    > student a écrit :
    >>
    >> What about setting a resolution of the LCD to be different than the
    >> "native" mode?

    >
    > It is usually considered a bad idea because it forces the monitor
    > electronics to interpolate the picture to the LCD native resolution,
    > and
    > the quality result can be very poor. LCD monitors are intended to
    > be
    > used at their native resolution.

    [snip]

    Agreed. LCD monitors don't work like CRTs. But you can get
    reasonable results with integer divisors of the native resolution.

    For example if the native resolution is 1280x1024 try putting,
    'Modes "1280x1024" "640x512" "320x256"' in your /etc/X11/xorg.conf
    file. Then control alt keypad_plus and control alt keypad_minus
    can be used to cycle through those resolutions on the fly.


    --
    Peter D.
    Sig goes here...

  12. Re: VerticalRefresh on LCD, does it exist?

    On 2007-07-03, Peter D. wrote:
    > Pascal Hambourg wrote:
    >
    >> Hello,
    >>
    >> student a écrit :
    >>>
    >>> What about setting a resolution of the LCD to be different than the
    >>> "native" mode?

    >>
    >> It is usually considered a bad idea because it forces the monitor
    >> electronics to interpolate the picture to the LCD native resolution,
    >> and
    >> the quality result can be very poor. LCD monitors are intended to
    >> be
    >> used at their native resolution.

    > [snip]
    >
    > Agreed. LCD monitors don't work like CRTs. But you can get
    > reasonable results with integer divisors of the native resolution.
    >
    > For example if the native resolution is 1280x1024 try putting,
    > 'Modes "1280x1024" "640x512" "320x256"' in your /etc/X11/xorg.conf
    > file. Then control alt keypad_plus and control alt keypad_minus
    > can be used to cycle through those resolutions on the fly.
    >
    >

    My xorg.conf does have the various resolutions.

    I looked up my display manual, LGE L1930B, & it stated that the resolution
    is 1280x1024 @ 60 hz AND 1280x1024 @ 75 hz; the LCD also has both DVI &
    VGA connectors. Don't recall what I did when I had VGA connections as
    I didn't think I changed the display to 75 hz; I do have the "near"
    current drivers for my ATI 9600xt.

    Still, both win & X only show 60 hz possible with the DVI connections.

    Not sure that it is a bad idea to have the electronics to do the
    resolution conversion; the HD TV does it when setup to do so instead
    of the "cable box" as the TV as per various postings on the AVSForum.



  13. Re: VerticalRefresh on LCD, does it exist?

    student wrote:

    > Have been trying out the native resolution. X doesn't allow much
    > changeing of fonts in various windows places or dialoges; firefox doesn't
    > allow much font changing in the title/menu/selection; opera does more but
    > still some boxes have a tiny text & some boxes/windows ignore the larger
    > setting for the text.
    >
    > WinXP does better in general but still in some dialoges (e.g. display
    > properties) are still in the "native" tiny faded (?) text size.


    Set your DPI to whatever you want.

    man xrdb

    set

    Xft.dpi: 120

    for bigger fonts

    Xft.dpi: 72 for smaller fonts

    and so on.

    Fiddle to your heart's content.

    --Yan

  14. Re: VerticalRefresh on LCD, does it exist?

    I've decided to use startx to set the dpi for X...thanks.

    Now, Back onto the topic/subject.

    Found that the ATI driver/software (ati control center) on windows
    offers a setting of a refresh rate of 75 hz as well as the "standard"
    60 hz; an option is included to set the 75 hz override for apps that
    want to refresh in 60 hz mode. The linux propriety drivers (amd/ati)
    don't have the same feature; both my winxp & linux drivers are "near"
    current (current is change for vista compatibility).

    A question arises for me in that does Nvidia drivers/software for
    the Nvidia cards have a similar feature for both windows & linux?
    Of course, this would be assuming that a 19" monitor spec allow for
    75 hz at 1280x1024. I would switch to Nvidia if the 75 hz use is
    available for both OSs as I will be updating my motherboard & cpu
    which also mean that it includes ram & video card.


  15. Re: VerticalRefresh on LCD, does it exist?

    on Monday 02 July 2007 02:51
    in the Usenet newsgroup comp.os.linux.hardware
    Nuno J. Silva wrote:

    > On Sun, 01 Jul 2007 11:11:23 -0500
    > student wrote:


    > In a correctly configured environment[1], changing the resolution will
    > change the quality of the image, but won't change the size of windows,
    > text and pictures. That's, lowering the resolution may make it harder
    > to read the text.
    >
    > [1] At least this is my opinion:


    Agreed. Unfortunately there are so many places that things can
    be configured that you should not be surprised when you find
    something misconfigured and something else misconfigured to
    "correct" the other misconfigured parameter(s).


    --
    sig goes here...
    Peter D.

  16. Re: VerticalRefresh on LCD, does it exist?

    on Wednesday 04 July 2007 02:19
    in the Usenet newsgroup comp.os.linux.hardware
    student wrote:

    > On 2007-07-03, Peter D. wrote:


    [snip]
    >> For example if the native resolution is 1280x1024 try putting,
    >> 'Modes "1280x1024" "640x512" "320x256"' in your /etc/X11/xorg.conf
    >> file. Then control alt keypad_plus and control alt keypad_minus
    >> can be used to cycle through those resolutions on the fly.
    >>
    >>

    > My xorg.conf does have the various resolutions.


    When you know what you are doing you can edit it.

    > I looked up my display manual,


    Excellent start.

    > LGE L1930B, & it stated that the resolution
    > is 1280x1024 @ 60 hz AND 1280x1024 @ 75 hz;


    If you are editing xorg.conf, "VertRefresh 60,75" means 60 or 70
    but "VertRefresh 60-75" means anything in the range 60 to 70.
    "man xorg.conf" for details.

    > the LCD also has both DVI &
    > VGA connectors.


    I don't know about DVI, but with VGA it is expected that any
    monitor can display the BIOS startup screen. What is that?
    640x512 or something even worse?

    > Don't recall what I did when I had VGA connections as
    > I didn't think I changed the display to 75 hz; I do have the "near"
    > current drivers for my ATI 9600xt.
    >
    > Still, both win & X only show 60 hz possible with the DVI connections.
    >
    > Not sure that it is a bad idea to have the electronics to do the
    > resolution conversion; the HD TV does it when setup to do so instead
    > of the "cable box" as the TV as per various postings on the AVSForum.


    If a logical screen line correspond to one and a half physical lines
    imagine what a fine series of black and white stripes would look like.
    Lines of black, white, black, white
    becomes black, gray, white, black, gray, white.


    --
    sig goes here...
    Peter D.

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