I also recall, vaguely, something about some adjustments in some 7K mainframes
to minimize things like readout jitter due to thermal heating of the vertical
position stages when the vertical has to make large and rapid changes in beam
position due to going from displaying readouts on screen to switching way off
screen to a trace way above or way below the screen. This is another "weak"
memory of mine. Maybe Dean has more on this . . .
Unfortunately, the IC vertical designs don't have a thermal compensation
adjustment. Again, the 7904 is an example, and my 7904s do suffer from
swimming readouts.
