> 
>    PCVT seems to know how to get the video back in the right mode (it
>    does so when you switch to a text vt).
> 
> No, it doesn't.  It relies on the X server to do that.
> 
> This is really part of a larger problem, that the interface between
> the `console' driver and the X server sucks.  In AIX there is (or
> perhaps was; they were talking about removing virtual terminals) a
> mechanism for the system to forcibly reclaim the terminal if the X
> server became unresponsive.  This may be one of the few things AIX got
> right.
> 
> Of course, this is easy to do under AIX, where the system already
> needs intimate knowledge of the video adapter.  We've been trying to
> avoid that on PCs because there are just *so many* different video
> non-standards, but I think it's inevitable that we need to `bite the
> cannon ball' some day.
> 
> Maybe we can have a default pccons-like driver, and make the
> device-specific code loadable; this would allow new devices to be
> `supported' without requiring people to rebuild their kernels.  This
> goes along with some of my other goals; namely making the terminal
> emulation machine-independent, and using mostly the same `console'
> code in all of the ports.
> 
At one point in Mach there was an ioctl that the X server would make to
"intern" a reset string of ioports and values to write. This would be
setup when the Xserver starts so that if it dies, the kernel can "play"
this reset string to the display device and clean it up.

I'm not sure if this is still in Mach and the associated Xserver.


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 John Brezak                    UUCP:     uunet!apollo.hp!brezak
 Hewlett Packard/Apollo         Internet: brezak@ch.hp.com
 300 Apollo Drive               Phone:    (508) 436-4915
 Chelmsford, Massachusetts      Fax:      (508) 436-5140