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Old 18 April 2013, 23:06   #2073
Join Date: Oct 2004
Location: Ioannina/Greece
Posts: 5,040

thanks for the tip, I played with the values you mentioned and got an approximation of what my monitor supports, I get no flashing pixels now


is it possible to add default VESA modes on the pre-configured list? If you take a look on the modes below (from my monitors specs sheet) , pc ones are referred to as "VESA" :

if those are indeed the exact VESA specs then it would be nice to have them available without micro-tweaking values... personally I did not find a combo for the 800x600@75hz mode that has those exact values, only close to those that seem to work OK...

I have found the following table that has detailed values on VESA modes, they seem to work fine with indivision for me:

source: , more timings here:

Jens is there a reason that the MK2 pixel clock values are not exact like on the table above? Or there is no reason to be exact values?
Also I notice there is no close value for 56.250 , 75.00 and 94.50 pixel clocks. I understand we still have a beta in our hands , just want to help

started cross-checking the default modes against the above table and found these differences:

640x480/60hz : difference in pixel clock , difference in vertical front and back porch
800x600/56hz: difference in pixel clock , horrizontal front and back porch , vertical sync and back porch
1024x768/75hz: difference in pixel clock , maybe 79.818 is better?
1024x768885hz: difference in pixel clock , the values jump from 92.6 to 96.2

after working with 800x600/75hz I found that setting the pixel clock to 49.094 gives a v-freq of 74.503hz and it works OK
setting it to 49.886 gives a v-freq of 75.705hz that has the moving pixels on the middle...
maybe my monitor needs exact 49.5 pixel clock to display an exact 75hz screen?

Last edited by keropi; 19 April 2013 at 00:14.
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