Manual - Holdan.eu

800 x 600 60 Hz
H/V Start [ 88] x 23
There is a period of time between the end of the Horizontal Sync pulse and
the start of Active Video. This portion of the waveform signal is called the
“Back Porch”, a term originating with the television broadcasting industry and
its RS-170A specification. In practice, this will control where the video image
starts on the left side of the monitor without changing the width of the sync
pulse itself (another way to control where the image area starts). The two
parameters control where the back porch is positioned and they interact to a
degree.
By adjusting these parameters, you control the start of the
back porch (with respect to the trailing edge of Horizontal
Sync) and also its width. The place where the Back Porch
begins with respect to the Horizontal Sync pulse and the
width of the Back Porch have a direct bearing on where the active (visible)
portion of the image begins. Do not attempt this adjustment without monitoring
the results with an oscilloscope.
800 x 600 60 Hz
H/V Sync [ 128] x 4
There are standards for all current computer and broadcast resolutions that
specify the correct width of both Vertical and Horizontal synchronizing pulses.
If you are creating a special, non-standard resolution, you may wish to adjust
the pulse width to fit your new requirements. The H/V Sync screen is where
that is accomplished.
Like the H/V Start adjustment, you must use an
oscilloscope when making these adjustments so that you
know exactly how many milliseconds or microseconds of
pulse width you have created. The numbers shown are
relative numbers and not an actual time measurement.
800 x 600 60 Hz
Sync polarity
Sync can be either negative polarity or positive polarity. To further complicate
things, it is possible that you may want to make the Horizontal Sync polarity
different from the Vertical Polarity. This control allows you to make that
change. You have four possible selections:
+H+V
-H+V
+H-V
-H-V
[+H+V]