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Re: This can't be true...
Jorge Chamorro wrote:
Michael J. Mahon <mjmahon@aol.com> wrote:
And I'm pretty sure that the exact duration or position of the Apple
color burst is not the real problem--I suspect it is the slight
departures from standard scan frequencies/durations, as Scott reported.
It depends.
If the problem is lack of color, then the culprit is more likely color
burst related.
If it doesn't lock to it, then the problem is more likely related to the
timing or to the "custom" shape of the Apple II vertical
sync/equalizing/serration pulses during vertical blanking.
Maybe...but recovery of the burst requires prior phase lock to
the horizontal sync, so things are a bit intertwingled.
I do agree that if the burst frequency is off by much, you won't
get any color, but the Apple burst frequency is right on, unless
the 14.31818MHz crystal has drifted with age (which they do).
I have an Apple ][+ that has drifted enough that it no longer
produces color images on an analog monitor! (I really should
get around to replacing that crystal...)
Macrovision did a fortune with this...
They sure did--but they inserted some big *very white* pulses in
the vertical blanking interval, and didn't fiddle with the timing
of what was already there.
-michael
Music synthesis for 8-bit Apple II's!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
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