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Re: Multinorm TV woes - no NTSC color display



Linards Ticmanis wrote:
David Wilson schrieb:


But my computer is a II+, not a IIe. What is the difference between NTSC
II+ motherboard and PAL II+ motherboard beyond the jumpers and the quartz?

Apart from the jumpers and the main oscillator frequency, nothing.
Making the changes you have done should return the board to NTSC
functionality. Have you tried tweaking the Color Tone variable
capacitor (C3)?


Hello David,

Yes, I did. Didn't produce any visible change whatever. That capacitor
modifies the color burst phase, not the phase of the visible picture
itself, right?

That's right.  And it doesn't modify the *frequency* at all, so
it would not affect detection of the color burst.

I see two possibilities--1) the 14MHz crystal you installed is just
enough out of tolerance that the monitor does not recognize the burst
as a color burst, or 2) the monitor is applying some strict criterion
to the video signal that the Apple does not conform to.  (This is more
of a problem with monitors that use digital decoding.)

-michael

New, faster SUDOKU v2.0 solver for Apple II's!
Home page:  http://members.aol.com/MJMahon/

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