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Author Topic: "Signal Out of Range" message on LCD - but showing 15khz picture!  (Read 9210 times)

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Offline Zac67

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The monitor tells you to better use its native resolution since all TFTs can not produce sharp output in any other resolution. I'm pretty sure there's some menu item to get rid of this message.
 

Offline Zac67

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Re: "Signal Out of Range" message on LCD - but showing 15khz picture!
« Reply #1 on: May 30, 2007, 05:25:15 PM »
Most of our Belinea and NEC monitors have options for turning off OSD.

Clock and phase are parameters to adjust the timing of the video input to the (static) LCD matrix. Since it's a digital display (essentially a large memory chip where you can actually see the stored data bits), the analogue input needs to be digitized/sampled and if the sampling rate (clock) doesn't match or the sampling takes place between pixels (phase) the display is blurry and may even show noise (flickering pixels).

Because the Amiga's output timing is in no way common to the industry, you may have to adjust those values manually:
- if possible set the video output to the TFT's native resolution or something with a simple ratio, e.g. 800x600 for a 17/19" 1280x1024, makes roughly 2:3 (OK); 640x480 is 1:2 (better); very bad is 800x600 on a 15" 1024x768
- display something with high contrast & lots of detail, full screen, a lot of small text will do
- change the 'clock' value to get rid of vertical stripes
- change the 'phase' value to get the sharpest possible display
- if you're not using the native resolution, there's no way to get a really sharp picture

Because this is prone to error (even when done automatically) it's much better to use a digital DVI input - the display is always perfect.
 

Offline Zac67

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Re: "Signal Out of Range" message on LCD - but showing 15khz picture!
« Reply #2 on: June 03, 2007, 11:33:33 AM »
You're right in most parts. I think the reasons for not supporting 15kHz modes on LCD monitors are:
- composite/component video requires additional electronics, RGB input is not common outside of Europe (Scart)
- nearly all video sources are interlaced, proper de-interlacing (including removal of comb effects) requires lots of additional logic
 

Offline Zac67

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Re: "Signal Out of Range" message on LCD - but showing 15khz picture!
« Reply #3 on: June 04, 2007, 07:35:39 AM »
Quote

DonnyEMU wrote:
14.32Khz (or 15Khz rounded up) is essentially the same NTSC/PAL rate signal...


PAL & NTSC horizontal scan rates range from  15.625 to 15.75 kHz.  ;-)