monitest - Monitor test program
monitest is intended to test ggi drivers (during development) and the
optical quality of monitors (later). Don’t be too disappointed if you
find a weakness in your monitor, mine is probably worse than yours.
The main feature is a test screen like broadcast in former days before
24 hour TV programs. It is used to test geometry and resolution of the
Also included are several test screens for testing moiree effects, the
horizontal and vertical screen resolution, and colour convergence.
You will be able to switch resolution on the fly, to find out
interactively what modes the driver supports and how much of this your
card/monitor can do with acceptable quality.
Specify the mode to use
The basic grid is white on black and has sixteen times twelve fields.
On a tube with 4:3 ratio each one should be square, even if the pixel
size of the screen does not have 4:3 ratio. The lines are one pixel
wide. They should be straight, even in the corners, and not have
There is a big circle in the middle and smaller circles in each corner.
They are round pixelwise, so they should be circles if the screen size
ratio (width:height of visible area) is equal to the pixel ratio. It
usually should be 4:3. So the best sizes for testing are 320x240,
640x480, 800x600 and up.
In each corner there is one box with vertical stripes. These are one
pixel wide, with one pixel distance, so you get maximum signal
frequency and can see how well your monitor and video card handle the
The middle field has eight solid blocks with the eight colours, i.e all
combinations of the red, green and blue signals turned on and off.
Below it there are four fields with vertical stripes as in the corners,
but in white and the three basic colours red, green and blue. Below it
there is a bar with these four colours red, blue, green and white
blending from full intensity (left) to zero intensity (right), i.e.
In the middle the current resolution is printed. Maybe horizontal and
vertical frequency will be printed too, if I can get the information,
which is not (yet) implemented in the LibGGI API.
Convergence means how well the red, green and blue picture are aligned.
This is tested by painting a grid of red, green and blue + signs. They
should be aligned properly where they touch. Usually they don’t...
There are four patterns like this, rotating the colours. Press space to
switch forward, or press q to quit anytime.
Once again there are several screens, press space to step thru them.
Vertical white stripes with width 1, 2, 3 and 4 pixels. See what the
highest dotclock is the monitor can handle.
Horizontal stripes with width 1 and 2 pixels. See how well the scan
lines are separated.
Three stars of black lines on white, with a width and space (at the
sceen borders) of 1 and 1, 1 and 5, 2 and 10 respectively. Watch for
colour changes, and once again you can see the maximum frequency your
monitor can do.
Vertical bars in red, blue, green and white, with the width of 4, 3, 2,
1, 2, 3 and 4 pixels for bar and space. See whether there is a
difference in resolution between the colours. And watch, again, for the
I don’t know whether these tests work, my monitor is rather good in
this respect. Please gimme some feedback!
If there is interference between the monitor mask and a grid displayed
on the monitor, a change of colours can be seen, and is sometimes very
annoying. There are three tests present, each one comes in the four
colour combinations black, red, green and blue on white background :
vertical stripes, one dot wide, with one dot space; white dots on
colour ground, spaced two and two (run testscreen with a really low
resolution to see what I mean :-); a chessboard.
FLAT PANEL TEST
This test allows you to drag a coloured rectangle around, looking for
pixels that are always on or off, which is, as far as I know, the most
common failure of flat panels.
The rectange is moved using the mouse or the arrow keys.
The color of the rectange can be changed by pressing the primary mouse
button (usually the left one) or <Space>, cycling through (black,
red, green, blue, white) or by pressing a number between 0 and 4 or the
first letter of the colour (b is blue).
Dragging with the second button pressed changes the size of the
rectangle. Every other key terminates this test.
BUGS AND LIMITATIONS
· If you switch depth, the program might crash badly. This will be
solved once I figure out mode checking or using a target that
(opposed to the X targets) supports that.
monitest was written by Hartmut Niemann.