IBM 5151 (MDA display) - common faults / gotchas?

[drlegendre .]

Persistence is directly related to beam intensity.. does it still linger so
long when its dimmed down?

Otherwise, I don't see any way for the phosphor chemistry to change much
over time, being hermetically sealed up in there. If anything, I'd expect
persistence to +diminish+ with age, as the materials deplete (if such
action occurs).

But like most chemical / physical processes, temperature may well have a
notable effect. Longer persistence when cold would make sense, in that
instance.

On Tue, Nov 11, 2014 at 4:42 PM, Ali <cctalk at fahimi.net> wrote:

> > I'd forgotten about the long persistence phosphor in the CRT until Tony
> > mentioned it - is it highly temperature-dependent
>
> It does take a very long time although 20 seconds seems a bit extreme. The
> first time I turned one on after not having used one for over a decade I
> was
> surprised as well.
>
> -Ali
>
>