Linux display help please

[BigV]

I have a problem. I recently improved my server room by swapping out three crt displays for three lcd displays. The room is MUCH cooler, and I have reclaimed a usable amount of real estate on the counters for keyboards and mice and notepads, etc.

Unfortunately, one group of servers that share a kvm switch (a couple of windows boxes and a linux box) does fine for the windows boxes but not for the linux box. The display (when that server is selected) reads "Cannot display this video mode". I swap out the lcd and swap in the crt, it comes up fine. To a text display, no gui.

I'm pretty sure the lcd display is functioning adequately, it works at at least 1024x768 as indicated by the windows boxes connected to it.

I don't think the resolution of the linux box is fixed at its current setting, whatever that may be. I'd be happy to change it to something more palatable to this display. But I don't know how.

So I'm asking:

1 -- How do I determine the current display settings?

2 -- How do I change the display settings?
2a -- for testing purposes.
2b -- for keepers.

Thanks in advance.