View Single Post
  #4   Report Post  
Posted to
[email protected] is offline
external usenet poster
Posts: 475
Default Composite video from Compaq Armada e500.

On Sep 9, 9:25*am, Peter Easthope wrote:
On Sep 8, 9:10*pm, wrote:

BIOS is usually at 640x480 but Windows sets it much higher.

It was back in 2011-03 or so that I connected the Panasonic TV
to the Armada and have forgotten some details. *I did set X to
640x480 and find the display on the TV still not resolved.

How closely is the composite signal tied to the built-in video on
a laptop? *I wonder whether software can control composite
output independently of *VGA. *Even so I'd wonder what X could do
to make the TV image fail.

I do video for a living and I have no idea what those scope


The sweep is set at 1 ms and trigger coupling is to TV-H. *How
do you connect a scope to the composite output on a computer
and what is the usual display?

Thanks, * * * * * * * * * * * *... Peter E.

I hunted up the Compaq Armada docs from HP and they are not really
clear on the TV output. They say the unit puts out composite TV. Here
is a link to a Tektronix page showing SMPTE NTSC color bars on a
waveform scope. The amplitude is 1 Volt p-p into a 75 Ohm termination.
Amplitude is typically 2 Volts without the termination. Bandwidth is
4.5 MHz for standard def. Line length from H sync to H sync 63.56 uS

The actual picture on the monitor of SMPTE bars

BTW no standard def monitor ever looked exactly like that Wiki
picture. If you made that image full screen your scope should look
like the Tek waveform scope.

Since they say the output is composite I assume the connector is an
RCA but nowhere do they ever show the connector, just the closed door
on the front of the computer.