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Re: RGB Card Question



Jorge ChB wrote:
Michael J. Mahon <mjmahon@aol.com> wrote:


I'd suspect that the colour burst being absent in the middle
of a frame would produce pretty bizzarre results.


Like for example ?
I ran the program above and nothing "bizarre" came on the screen.

I didn't say something bizarre *would* happen, only that it *could*
happen, because it is completely outside the NTSC specification.


Yep, the most "bizarre" thing that could happen is a switch from color
to monochrome, or viceversa...

No--actually, loss of color sync could result in some "rainbow"
displays for part of a frame as the monitor color reference
oscillator tries to get back into phase lock.

The "trajectory" of phase lock during reacquisition can be
chaotic, so, with the "right" timing, wierdness can happen.

Some monitors may incorporate circuitry to detect solid phase
lock of the reference and disable chroma processing until it
is achieved, but I'd be surprised to find this in non-professional
monitors.

-michael

Parallel computing for 8-bit Apple II's!
Home page:  http://members.aol.com/MJMahon/

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