Re: /dev/tty0 for alternate card?

From: James Simmons (
Date: Thu Jun 15 2000 - 10:22:16 EST

Have you tried Xinerama? By the way /dev/console is very important to
a XFree86 server. Unless you have the X server configured to use /dev/fb
the X server programs the video hardware in userland. Also the X server
needs to read the keyboard directly. This means the tty has to set the
keyboard into RAW mode. This requires using a special VT API to handle VT

> Are the tty's tty# only associated with the primary display?

Yes. Unless you use /dev/fb which can map a VT display to a different
video card. Note the current console system does not properly support
multiple keyboards. I'm working on code to handle this for the next
developement kernel.

> As far as BIOS is concerned, can there be only 1 display?

With most BIOS they have a hard time with multihead setups. Trust me I
have 4 video cards in my system and they are a pain to get to work
together. To support multihead you need to create video drivers that can
boot the video card without the help of the BIOS or the video ROM if the
card has it. This also makes the video driver work on multiple platforms.

> The documentation on the console_ioctl man page says that
> it's probably only accurate w.r.t. 1.x kernels (was last updated
> in 1995).

The console system has changed much in the last few years. The ioctl
haven't changed at all.

> Can tty output be "quenched" like appeared
> to happen without interacting with tty# (some other driver?)
> apparently the X server does not close stderr.

If you mean can video be displayed by some other way besides the userland
/tty solution then yes. Its called fbdev.

Q: Why did they deprecate a.out support in linux?
A: Because a nasty coff is bad for your elf.

James Simmons [] ____/|
fbdev/console/gfx developer \ o.O| =(_)= U

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