Chris' XFree86 stuff [was: Re: [plug] usbkeybd device under Debian?]

[Chris Caston]

On Tue, 2003-12-30 at 17:42, James Devenish wrote: 
> Hi,
> 
> Is this related to your previous message about your LTSP XFree86
> project?

Yes. That is what I am working on. Unfortunately I had to sell most of
my test machine to customer but I've put the drive in my main machine
and am now playing with that. I will be building another Athlon machine
when the wholesalers open again in January. This machine only has one
good USB port as well as a VIA USB2 PCI card. It does have some more
onboard USB ports available but I need to wire them up.

>  I wasn't really paying attention at the time. What is the
> aim/advantage of this project? I tried Googling for information about
> the XFree86 patches but I kept getting results about using multiple
> keyboards, multiple mice, etc. I assume you're looking for some sort of
> user-switching capability like with Windows and Mac OS?

Well the idea is to have one machine and multiple people using it
simultaneously. 
>  I've never tried
> this under UNIX without using VNC, but with Linux you can get a few
> users out of the virtual consoles. I can't come up with a really good
> example, but if you become root and run `startx -- :1`, 


That's a simple way of doing it but i've had problems with it. In KDE if
your using KDM you have have a start new session feature. Checkout:

"/etc/kde3/kdm/Xservers"

for: 

:0 local at tty1 /usr/X11R6/bin/X -dpi 100 -nolisten tcp vt7
:1 local reserve /usr/X11R6/bin/X -dpi 100 -nolisten tcp vt8
:2 local reserve /usr/X11R6/bin/X -dpi 100 -nolisten tcp vt9
:3 local reserve /usr/X11R6/bin/X -dpi 100 -nolisten tcp vt10  

> you will get a
> second X environment that is accessible via Alt-Ctrl-F8 (I think that's
> correct for Intel architectures). Not quite "perfect" for user switching
> because a user might forget to lock his/her screen before stepping away
> from the machine, and you will presumably only be able to support a
> small number of simultaneous users, but it sounds better than having
> multiple keyboards, at least. Not quite sure what your project needs,
> though.

It does need the multiple keyboards. I also found out that Linux supports USB speakers and headphones and they should
work in most apps! (:

If you want a better idea of what I am trying to do you may look at one Windows version called BeTwin from http://thincomputinginc.com

I eventually plan to actually rig this up so that it is part of an LTSP environment and each LTSP client can have multiple users.

There are many advantages to this such as less costs buying hardware and replacing failing compenants like memory and
 power supplies. The user environments will also be less noisy, less prone to theft and consume less power as Harry pointed out.

An LTSP client with 5 PCI video cards each having say 128-256mb of video card ram could possibly have the unused video 
card RAM pooled together as swap space. This could be very interesting.

In order to support this setup (different input devices for each virtual terminal) there needs to be some 
changes to the Linux console/TTY system. These are under developed and can be applied for 2.4 and 2.6 and the Ruby patch.

http://linuxconsole.sourceforge.net/

"Our charter is to clean up and properly maintain the Linux console/TTY sub system. There has been scattered work on the console and TTY layer going on for some time. This project will try to pull it all together into a coherent architecture from which we can generate clean patches for Linus and the core kernel team."

"Multi-desktop operation -- console instances running on multiple (possibly dissimilar) video cards and separate keyboards."

http://startx.times.lv/

You also need to make changes to XFree86 so that it doesn't hang or turn off the other unused video cards. The patches are available
and can be applied to XF864.3 as well as earlier versions.

There are also precompiled .debs on:

http://www.schuldei.org/debian/bruby/

I highly recommend checking the Linux console mailing list for more information. I will be working on implementing this
during my free time and I feel that it will help me to develop my Linux knowledge as well as work towards deploying this
exciting product that could bring Linux into many more places than previously possible.

regards,

Chris Caston


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