[mythtv-users] MythTV through a KVM Switch

[John Welch]

For the last few months I have had a Linux box, primarily being used
as a MythTV frontend, connected up to a Samsung 26" LCD HDTV.  The
video card in the system is an FX-5200.  Recently I have had the
occasion to also connect up a Mac Mini to this TV.  Now, when I first
got the TV I was not able to get it working with the Myth box when
connected up via a DVI-HDMI cable.  After reading in the TV
documentation that the HDMI input did not support a PC connection I
moved on to connecting up via the VGA port.  After a little tweaking
everything worked fine.  When I connected up the Mac Mini just for the
heck of it I once again tried using a DVI-HDMI connection, and was
pleasantly surprised to find that it worked.  So, I had both systems
connected to the TV through different inputs.  Not wanting to keep two
mice and keyboards around I decided to purchase a KVM switch.  At the
time I shopped around I was not concerned with the video part of the
switch, and was more concerned with getting something that I could use
with both the Mac and the Linux boxes as far as the keyboard and
mouse.

Right off the bat when I connected the Mac Mini to the TV I was not
getting it to display to the full resolution of the TV, which is
1366x768; instead I was getting 1280x720.  The text on the Mac Mini
was also not as sharp as on the Linux box connected up to the VGA
port.  I thought I would be able to make some adjustments to correct
this.  However, after playing around with some settings and doing some
searching about on the web I am convinced that I am not going to be
able to get as good of a picture on the DVI/HDMI input as I am on the
VGA input.  So, now I've decided to try to get both systems connected
up via the VGA input using the KVM switch.  The Mac Mini works fine.
I am now able to get the maximum resolution and the picture is much
sharper.   However, my problem is on the Linux/Myth side of things.
The system boots up fine.  The only noticeable difference is that some
of the startup text is a little bigger than it was when I had the
system connected directly to the VGA port of the TV, but it is
actually a little clearer.  When I login to my KDE desktop everything
looks the same, as the text and icons are the same size.  But when I
fire up the Mythfrontend and go to Watch Live TV this is where I see a
difference.  Before I made the connection change standard TV channels
would show up in the standard 4:3 ratio and I would have to adjust the
Myth settings to 16:9 to fill the screen.  HD channels would
automatically fill the whole screen.  This is the behavior I would
expect.  Now when I view standard TV channels the whole screen fills
up, and when I view HD channels I get big black bars on both the top
and bottom of the screen.  I'm not seeing any errors related to the
display, and it still appears to be at 1366x768, but something has
obviously changed with how the box is recognizing the TV.  I booted up
the system while directly connected to the VGA port and then swapped
the cables over to the KVM and everything worked the way it should.
So, I'm pretty sure that the KVM is capable of handling the full
resolution.

Anyone have any clues about what settings I need to adjust to get
things working properly through the KVM switch?  Alternately, I know
it's way off the MythTV topic, but if anyone has any ideas about how I
can get the Mac Mini working at full resolution with the DVI-HDMI
connection I'd be willing to go that route also.

TIA,
John