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Re: Problem 2: no color -Re: Vertical Sync Issues with modern TV
Mike Willegal wrote:
Ok,
Those old boards were designed to work as PAL or NTSC. Cut a couple
of traces and add some blobs of solder to convert. Didn't notice the
difference until I compared it to a "working" NTSC board.
New Problem:
I've changed the board back to NTSC, but now I don't get any color.
Tried two different TVs and an RF modulator. My other board of the same
vintage also doesn't exhibit any sign of color, either, though it never
had the issue with PAL sync timing. I do get shades of grey.
Besides the different sync frequency, NTSC needs the color burst
at the beginning of each line. I forget whether PAL needs that, but
even so it would likely be different.
It might be that a different jumper sets that. I had an apple2
schematic about 20 years ago, but I haven't looked at one since.
-- glen