Re: monitors & video cards (was: JPS?)

[P3D Andrew Woods <andrew@xxxxxxxxxxxxxxxxxxxxx>]

Larry Berlin wrote:
> Most modern monitors are
> Non-interlaced. They refresh the entire screen each cycle. In fact some
> systems, this includes video accelerator boards and monitors, cannot handle
> interlacing the display itself.

Just to clear up some possible misunderstandings regarding monitors
and video cards...

A non-interlaced monitor is still capable of displaying interlaced video.
There is nothing inherent in the monitor which stops it from doing
interlaced video.
The "non-interlaced" probably means that it has high horizontal
frequency capabilities and is therefore able to cope with non-interlaced
modes in addition to the usual interlaced modes.  The horizontal
scanning frequency for non-interlaced modes is twice that of the
equivalent interlaced mode.

It is true that some video cards are incapable of switching to an
interlaced mode.  It is then necessary to use page flipping to 
display a field-sequential (frame-sequential) stereoscopic image.

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.

The maximum pixel rate of a video card is not normally specified
on the spec sheet.  What normally is specified is the max.
refresh rates the card is capable of generating for a specified
resolution and interlacing mode - but this is determined by the max
pixel rate of the video card.

Andrew Woods.


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