C64 and display problems
Posted: Thu Oct 07, 2021 6:26 pm
What could be the reason:
with the luma signal: "the screen jumps 3 points vertically (such interlace but 3 points) - the lower frame is thin (the height of the text line, then it is not black, but the whole screen is stretched so that the lower frame is about 8-9 points)
after connecting the chrome:
the image quality deteriorates even more and you can see such colors as in a noisy photo from a digital camera.
Could it be the VIC 8565?
I connect it on the low side, not through the modulator
soft comes: sprites, etc., scrolling, etc.
here is a diagram (there is no modulator diagram, which can also be damaged and introduce interference)
I do not have an oscilloscope to watch the signals, maybe someone will intuitively throw a few possible damage and a method of diagnosis.
with the luma signal: "the screen jumps 3 points vertically (such interlace but 3 points) - the lower frame is thin (the height of the text line, then it is not black, but the whole screen is stretched so that the lower frame is about 8-9 points)
after connecting the chrome:
the image quality deteriorates even more and you can see such colors as in a noisy photo from a digital camera.
Could it be the VIC 8565?
I connect it on the low side, not through the modulator
soft comes: sprites, etc., scrolling, etc.
here is a diagram (there is no modulator diagram, which can also be damaged and introduce interference)
I do not have an oscilloscope to watch the signals, maybe someone will intuitively throw a few possible damage and a method of diagnosis.