KVM cards

[bscott at ntisys.com]

On Mon, 7 Oct 2002, at 10:08pm, mod+gnhlug at std.com wrote:
> I can't remember ever hearing of such a thing - all this would really
> amount to is something on the order of a 1-port KVM switch implemented as
> (say) a PCI card, right?

  That would work if your laptop had a PCI slot.  Which it don't.

  It also would not work because a laptop display does not have a
analog-to-digital converter -- the frame buffer is connected more-or-less
directly to the dot matrix [1].

  That being said, you could do what you -- and I -- want in one of two
ways:

  (1) Video capture (and keyboard and mouse generation).  The display data
would have to go through the system bus, and possibly be processed by the
host OS, too.  This would mean you could (in theory) put the KVM in a window
on your own desktop.  VNC-over-VGA, anyone?  :)

  (2) Add the analog-to-digital circuits present in non-laptop flat panel
display, along with some supporting logic to do the KVM switching.  This is
actually largely the same thing as #1 above; it simply does it all in
hardware.  You gain performance, but lose the KVM-in-a-window trick.

  Alas, this is all academic; I know of know such laptop that supports such
functionality.  Nor do I know of a CardBus card which implements option #1
(which is likely the most feasible way of doing this).  The best I have seen
was an easy-to-carry flat-panel-and-keyboard kit.  Which beats lugging a CRT
around, I suppose, but not by much.

> ... please don't bother suggesting that I consider using serial consoles
> or any other such civilized solutions that one might expect on machines
> designed by/for grownups - we're talking about PeeCee's here...

  Are we talking PeeCee's running Linux?  If so, setting up serial console
support is trivial.

  If we are talking MS-Windows, well, you're screwed regardless of hardware
support.  (For example, NT runs on the Alpha, and the Alpha's serial console
is just as useless with NT as it would be on a PeeCee.)

  Also, and FWIW, most decent "server" PeeCee's these days have serial
console support built-in to the firmware, too.

Footnotes
---------
[1] Okay, that is a lie, but it will do for purposes of this discussion.

-- 
Ben Scott <bscott at ntisys.com>
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