[SGVLUG] SCALE5x Booth - Volunteers and Ideas: LinuxDoc and DumbTerminals

[juanslayton at dslextreme.com]

> > Dustin Laurence wrote:
>
> > > What would be rather cool would be a computer running full multiple
graphical terminals, like has been advocated for schools.
> > >
> > > I don't know a think about it, though.
> >
> On Mon, Dec 25, 2006 at 11:25:25AM -0800, Jeff Carlson wrote:
> > Ooh.  I heard about something like this.  Basically, one computer with
multiple video cards (or dual-output cards), and multiple USB
keyboards
> > and mice.  Each video output is paired to a keyboard and mouse (as
opposed to a normal multi-head display) and thus they become terminals
to the computer.
> >
> > I think that would make a very viable demo.

At first I was amazed at this but then on further consideration didn't
really believe it.  Then I searched the Internet and found that my doubts
were partly correct.  The problem is that by design, the USB and monitor
cables are for short distances only, like a few feet.  So that rules out
connecting a lot of monitors and keyboards to one PC.  But what is "a
lot"?

It's claimed that one can connect 9 additional monitors and keyboards to
one PC.  I guess it might look like a table with the the computer in the
center.  The commercial name is "userful" and it costs about $100/seat
(retail).  So it's not free but they let you try out a
2-user system free.  Is there any free alternative?

This setup is a genuine GUI dumb terminal since monitors and keyboards
have nil computing power.  The other alternative, the Linux Terminal
Server Project (ltsp), uses low-power computers at each workstation so one
could call them smart-terminals (but people sometimes also call them "dumb
terminals").  Since low-power computers (low in both
computing power and electric power) are cheap these days, it's not too
much more expensive than the direct connection which requires a number of
video cards.  And with ltsp you can locate these smart-terminals (AKA thin
clients) a long ways away from the server.  Also, old used computers that
are nearly free in cost (except for the electricity to run them) can be
used as thin clients.

One question.  For the direct connection, is there a server?  I don't
think so since keyboards and monitors aren't computers and can't
possibly be clients.  And without clients, you can't have a server. That's
the way it was with old dumb terminals in the 1970s and 1980s. It's just
multiuser.

Since both schemes use Xwindow, you likely will not be able to get a
text-console screen (virtual terminal) although there's always xterm.

			David Lawyer


     One free alternative would be 'xephyr.'  Go to www.c3sl.ufpr.br, then
click on 'our projects,' 'multiterminal,' and 'more' in turn. 
Someone would have to do a bit of work to set this up.

     If you just want multiple keyboards feeding terminal, I can give your
20 usb boards, each printing to a separate area of a common display.

John Slayton