Before I get too far into it, let me begin by pointing out that
your needs may best be met with X terminals or other inexpensive displays.
The product described below is most suitable if your performance
requirements outstrip an X terminal's ability to deliver, or if
you seek a cost savings by redeploying an existing stock of machines.
I solved this problem as a consultant to DEC for a large military bid.
We called the products SEATS.
SEATS includes software drivers and cabling to extend the
single-user nature of Digital Unix/ DECwindows to multiuser limited
only by the number of slots (6 for a turbochannel system). It uses
Digital-standard hardware for graphics, keyboard, and mouse. To add
a second user, a small pigtail cable ties into the onboard spare serial
ports. For up to 6 users, a Magma 8 port serial card is required.
In the final iteration of SEATS, we redesigned the ZLX turbochannel
graphics controller with a DEC mouse/keyboard port so that our product
would have a consistent, robust, hardware basis. All of the existing
DECwindows session management function is preserved. The users see
their DISPLAY variable set to :0.0, :1.0, :2.0, etc.
I spent some amount of personal time and expense marketing this idea,
but found virtually no interest in the marketplace. The turbochannel
window of opportunity is pretty much closed, oh well.
DEC CSS (Custom systems) and GPO (govt program office) were quite pleased
with this product. I believe that if a good sales opportunity came along
they would resurrect it.
Stuart Kreitman
Faster Raster Systems
>
> Hi all,
>
> We have two related problems that we somehow believe not to be unique.
>
> At our department the demand for work places (i.e. screen + keyboard)
> is somewhat out of sync with the demand for computing power so that at
> some times we have more computers than we can place on desks and at
> other times we are simply out of screens.
>
> 1) So, is it possible to attach more than one screen (with keyboard
> and mouse) to an alpha and have them act independently (as if we
> actually had more computers). I understand that you can put several
> graphic cards in, but is it possible to hook up several keyboards to
> one computer and make the computer associate them with different
> screens?
>
> 2) The other problem is that for reasons of reliable electricity and of
> cooling (and noise!) we try to keep the computers in the computer hall
> instead of in the offices. Now, the video signal from the graphics
> card doesn't travel far enough to pull the screens out far enough for
> more than a few offices, closest to the computing hall. We have been
> tinkering with the idea of building a video signal amplifier, but it
> seems (to the lay man) somewhat more conservative to pull the digital
> signals that go into the video card (from the bus) out and amplifying
> them, rahter than amplifying analogue signals. I believe I have seen
> Suns with graphic cards integrated into the screens where the graphic
> signal was brought in digital form over ethernet (or similar) from
> some distant computer hall where the actual boxes were stacked. Is
> there something similar for alphas? Did anyone think about or solve
> this problem before?
>
> Many thanks in advance,
>
> Simon.
>
> Simon Tardell, voice +46 8 162688 fax +46 8 347817
> Fysikum, Stockholms universitet simon_at_physto.se, tardell_at_particle.kth.se
Received on Mon Feb 19 1996 - 17:30:21 NZDT