Monitor fed by VGA and DVI-D thru KVM

Tech Zero wrote:
Reality folded in on itself, and somewhere the following words from
"Jaz" appeared in history:

One last thing, when I mentioned "adapters" I was only referring
to a connector format change from 15-pin d-sub to DVI-I. This
simply lets me plug a VGA cable into a DVI-I port on the KVM
switch. These adapters are everywhere -- one comes included with
almost all DVI video cards.

Just to add to Paul's comments, at the "bolts" side of things as it
where... The adapters that DVI-I cards have a male DVI-I connector
with a female sub-D VGA at the other end, so to put it bluntly *the
genders don't match there mate.

Simple Rules:
- Video cards have female connectors
- Monitors have male connectors
- Video cables only go in one direction

This was origonaly done to differentate serial ports from video ports
back in the CGA days, since they used the same style connectors.

Video have as evolved since then but the gender diffrences remain.


That said, there are DVI-A cables out there that may work; thay have
a male VGA connector at one end and a female DVI-A connector at the
other... But I don't know if they have nay issues...

Most HD15 VGA cables seem to be Male-Male. Some KVM switches are Male
(Tripplite) which require a M-F cable, but... Anyway, I beliave all
video cables are functionally bidirectional -- if the gender doesn't
match then a gender-changer is in order.

I spoke with a very knowledgable fellow at Lindy Computer Connection
Technology Inc, specifically about their #41219 cable, and they said
that what I'm trying to do should work, at least with their own KVM.
They also said that the generic DVI-I-to-HD15(vga) adapters that you
typically use for changing a video card's DVI-I output to HD15 for
your VGA monitor, are bidirectional, and should 'do the right thing'
on the KVM's output (testing using a VGA monitor -- without the
splitter).

I hope this is true, since I can imagine there could be lots of issues
with various signals like you describe, such as monitor type/
manufacturer, etc. Certainly this could be be the culprit. Any takers?

Over the past week I emailed and phoned TRENDware to get the final
word on whether this is a digital-only or analog/digital switch, and
they maintain that it's indeed DVI-I analog/digital. I asked if it's
possible that something might have been lost in translation with the
Taiwanese manufacturer's specification sheet and that it may not
actually be DVI-I, but DVI-D instead. They said 'No'. Hmmm... I
suppose that aside from cabling problems, it's possible that my switch
is faulty and needs to be replaced.

Another problem I see is with the DVI source PC -- it starts up in
analog mode if that port is not active at boot-up. Sheesh! Is there no
end to these issues?! Might this be a shortcomming of the DVI
standard? Shouldn't the KVM switch provide the needed signal to the
DVI source so that it doesn't default to VGA mode? (and because this
KVM doesn't pass analog, the monitor is blank).

Well, perhaps the best thing to do at this point is to go all DVI-D/I.
The reason I didn't in the first place is that two of the old PCs
simply don't have the option of changing cards (built-in VGA) -- they
have needed stuff on them I and don't want to spend the effort in
moving application and data to new systems.

--Jaz
(Please excuse the 'burp' when replying (b))