> Our computers are more special, ie. conform to the original spec is > generally a "don't care" bit as long as the construction provides > colors, :-) > Also, if someone creates a pattern of black and white stripes on the > screen, one pixel of width each, he'll see a color gradient on top of > the stripes on composite displays... As explanation, the pixel > clock of > the PAL C64 is 16/9 the color subcarrier frequency. A series of black > and white pixels is therefore a square signal whose base frequency is > half that, in other words 8/9 of the color subcarrier frequency - very > close, almost equal. This signal will definitely be catched by the > chroma separator in the display, and get displayed as color. As this > signal'd be constantly shifting in reference to the PAL burst > (since it > is "slower" than that of PAL's nominal frequency), the result is a > gradient of constantly changing color. From the proportion, we could > also conclude that the gradient is periodic for 16 pixels. > > ...Now, imagine how that'd look like if the PAL reference phase was > unknown, or constantly shifting... :-DDD Someone should make some pictures, hint hint :-) Segher Message was sent through the cbm-hackers mailing listReceived on 2011-11-17 18:00:05
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