What makes the 2D quality of Matrox better then other ?

[Slashhead]

Rylan and Rubank,
Take a look at the graphic below (the signal for one of the RGB channels). Made by myself with Excel
note: i mixed the colors black and white. White=750mV and black = 0V


Asume that we have 14 pixels that needs a certain color. Is the DAC signal for these 14 at a certain level all the time. I mean when there are several pixels in a row with the same color, is it necessary for the DAC that it reaches it's zero level after each pixel is finished ? Or hold the voltage as shown with the RED line, since the clock is switching between the pixels. When it works like this you may have blurry edges by color changes on the screen like the BLUE line is illustrating( a word document for example). In that case it makes sense to me that the quality of the filter is very important and also the output of the DAC.

So, I am off for the weekend now and will be back monday.
Thanks for all your answers this far it was very usefull to me.


[This message has been edited by Slashhead (edited 20 April 2001).]

[This message has been edited by Slashhead (edited 23 April 2001).]

[rylan]

As long as the brightness/color isn't changing on the screen, the DAC holds the output signals constant. So if you have full white (or full blue, full red etc) then those lines will be held up around 750mV. So, as you mentioned, if you have 14 pixels on a line (horizontal) that are the same, the dac output will just be held. But once you go change color or brightness, then the level just changes to what it necessary. If you looked at the video signal when you have a picture up in windows, it would be damned ugly, since the dac has to constantly swing all over the place to generate the appropriate colors and contrasts.

As you mentioned, one of the spots you can see the 'fuzzyness' is at the edges of text, as thats usually a full swing from black to white.

[Maggi]

<font face="Verdana, Arial, Helvetica" size="2">Originally posted by rubank:
Hi Maggi,

there seems to something wrong with your calculator,

or is it to much beer

rubank</font>

LMAO

nope, Rubank ... I used Powerdesk for a readout.

[rubank]

Maggi,
that´s cheating!

rylan,

I certainly don´t doubt you, but that means the video output is AM, yes?
Perhaps someone should try FM

rubank

[Rags]

Digital interface is going to put this all behind us.

I hope.

Rags

[rylan]

rubank: yeah, the video output signal is Amplitude Modulated.. heheh.. kinda funny when you think if it like that. I guess they never went to FM bacause it would require the CRT driving circuitry to be redesigned.

Yeah, DVI is where everything is going. DVI-I looks to be the best standard out there currently.. it allows for digital interfact to flat panels, but also has analog signaling lines for CRTs.