Re: monitors & video cards

[P3D Andrew Woods <andrew@xxxxxxxxxxxxxxxxxxxxx>]

Greg Marshall wrote:
> Yes, a non-interlaced
> monitor will generally display an image from an interlaced
> source, but it may not get the interlace right.  That is, each
> field will show on top of the other rather than vertically
> offset (interlaced).

Sorry, this is simply not true.  An interlaced video signal determines
the position of the odd and even fields by the relative timing of the
horizontal and vertical synchronisation signals.  The monitor 
would need to do something extraordinary to defeat the interlacing
generated by the video source.

Larry Berlin wrote:
> The problem is in getting the signal interlaced in the first place since
> that isn't the way a computer handles the video signal.

This was my point exactly.  Whether or not your computer can do interlaced
display depends only upon the video card.  It's got nothing to do with the
monitor.

> unless you interlace the signal
> outside the computer, which some viewing systems do.

I would be surprised if this is the case, do you have any further information?

I wrote:
>The maximum refresh rate that a particular video card can generate
>for a specified resolution (640x480, 800x600, 1024x768) in either
>interlaced or non-interlaced format is determined by the maximum
>pixel rate of video card.

Larry Berlin wrote:
> While that may be true for some cards, I have tried the Total3D
> card on several different systems and monitors. Monitors are NOT all the
> same. 

Agreed!  Sorry if I did not progress to the next logical step but at
this point I was only referring to the maximum rate of the _video card_.
Of course the maximum refresh rate of your SYSTEM will be determined
by the limits of the video card _and_ the monitor.  

I still contend that what a manufacturer means when they say that
a monitor is "non-interlaced" is that the monitor has a high rating 
for horizontal frequency.  After having a look around the web at the
specs of various monitors I am yet to find one specifically advertised
at being "non-interlaced" - does anyone have any examples?

Cheers,
Andrew Woods.


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