Re: Mk14 vdu
I'm trying to think of a way to prove that the shudder shift is regular and on a frame by frame basis rather than variable, on a line by line basis.
If I draw a test image which just consists of a number of one pixel wide vertical lines, then, if the whole frame is shifting back and forth I would expect that to the naked eye each vertical line would become two equally evenly lit transparent vertical lines lined up against each other.
If, on the other hand, the shudder is occurring semi randomly on a line by line basis then I would expect that both of the vertical side-by-side lines would shimmer like faulty striplights because for any given pixel line, the line might or might not be offset.
I'll prepare or generate such a test image - could be as simple as writing 0x01 to every screen RAM location - and see which effect I get.
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