Re: Query: Set screen color depth on a per-user basis via GDM?

["Guillermo S. Romero / Familia Romero" <famrom idecnet com>]

jonathan searle ntlworld com (2001-02-04 at 2022.05 -0000):
> We did consider using CTRL-ALT-PLUS/MINUS to cycle through
> preconfigured system-wide color depths, but this proved too unwieldy and
> confusing, especially as the students are not very linux literate.

IIRC that does not provides color depth change, but "hardware zoom".

> Does anyone know if it's possible and how I should go about setting
> it up?
> Or is there a more elegant way of doing this?

Launch multiple X servers with GDM, each using different bpp. I have
not tried it, but I guess it should work fine.

Edit gdm.conf, and change [servers] area to get something like this:

---8<---
[servers]
0=/usr/bin/X11/X -bpp 32
1=/usr/bin/X11/X -bpp 8
--->8---

That way you will have one in 32 bpp (24 bit color), and another in 8
bpp. You will switch from one to another with Alt + Ctrl + F# (#
probably 7 and 8).

They will have to login two times. Uumm, worst case would mean that
you can not run Gnome, but another system, a plain wm (Gnome and
related software seems to be a bit flaky about exceeding disk quota,
simulateneous sessions and other situations that other software
handles more nicely).

Another option would be using Xnest, supposing your systems allows
having a Xnest at 8 bits running inside the true X server at 24 / 32.

GSR