Is there some kind of machine monitor in Mandrake that can be activated by a hot key? It has twice happened now where my Mandrake machine entered a strange mode where the letter "o" on the keyboard turned the machine off. In the first instance, the system switched to a text screen much like the failsafe text mode. However, in the 2nd instance, the regular GUI remained.

By trial and error, I have since found that CTRL-ALT-<Fn> (for n = 0 to 7) will switch the screen to any one of 7 local TTYs, where TTY7 is the everyday GUI interface. So, you can have 6 text console sessions in addition to the GUI session. However, I still haven't found the answer to the question I put forth above and I have seen nothing anywhere that even comes close to describing this.

CTRL-ALT-F7 will switch to the X11/X.org screen.
CTRL-ALT-F1-F5 will switch to a console.

If CTRL-ALT-F7 does NOT bring up a graphical screen then your window manager or X has died unexpectedly.

This normally indicates a driver or agp driver issue.

If CTRL-ALT-F7 does bring up a graphic screen, but it looks "funny" then try CTRL-ALT-[+] or CTRL-ALT-[-] (that's plus or minus respectively) which will switch between different defined resolutions.

If "X" is going wacky on you from time to time, update/check your graphics settings, libs, drivers and resolution.

Also,CTRL-ALT-F6 also gives a console. CTRL-ALT-F8-F12 give a blank screen. My understanding is that all of this is a feature of linux in general and not just Mandrake. Is that true?

Interesting about CTRL-ALT-[+] and CTRL-ALT-[-]. X and the graphical interface are behaving fine and none of the above are occuring. It's just that this "machine monitor" like program shows itself, it has been twice now. It appears to be some kind of emergency recovery or debugging tool. I was wondering what hot keys bring that up.

This is true for all Linux distros, I believe.. And CTRL-ALT-F8 - CTRL-ALT-F12 are reserved for additional GUI sessions. If you start additional sessions, they will be assigned to these keys. I occasionally start a seconf X-window session, and hot-key to it using CTRL-ALT-F8.

I have never seen this, so I don't have any idea what it is or how to bring it up.

He may be talking about the dump you get from the sysreq key or the debug screen.

That would seem to fit the bill. But CTRL-ALT-SYSREQ, with or without the CTRL or ALT keys, does nothing. So, how would that screen come up?