WAIT, PRINT and timeout

[StephenG1CMZ]

If the screen dims, is there a standardised button that will un-dim it?
Without doing anything else?
(Comparable to hitting Shift on a PC, which is often the least intrusive key to press).

Or will we need logic like:
Wait until tap (but ignore tap in this pixel, except maybe for calling MAKEBRIGHT).

And if a program wants to ensure the screen is bright, is there such a routine - or is writing something to the screen sufficient to un-dim (if so, can you write NULL?)

I don't yet have a Prime to check for myself.