On Thursday, 22 June 2017 11:00:07 UTC+1, Brian Gaff wrote:
I think the thing about crts was that since the controls were all basically
either magnets or waveforms fed to the scan coils, one always affected
another.

indeed

You cannot really screen one electon beam and only control that
one.

that has been done, but not in mass market sets. Early sequential colour systems involved doing that with a single gun tube.

The shadow mask was of course fixed

I saw one that wasn't. A weird viewing experience.

and one hoped the combined tolerances
of all the parts agreed enough that only minor adjustments were in fact
needed.

never true

the corners were always way out of course

they weren't

but apparently the eye
never noticed that much.

it did when they were

Why it took so long to phase out the CRT I shall never know as it was
obviously the week link in the chain.

cost.

I suspect it was the complexity of
driving such a flat screen display that only became feasible with large
scale integration and digital processing.
Brian