FSR MAS-6100, Installation And Operating Manual

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MAS-6100 / MAS-6100A
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 specifi cation. 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.
NOTE:
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 800 x 600 60 Hz
H/V Sync [ 128] x 4 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 fi t your new requirements. The H/V Sync screen is where that is accomplished.
NOTE:
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 800 x 600 60 Hz
Sync polarity [+H+V] Sync polarity [+H+V]
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. There are four possible selections:
+H+V
-H+V
+H-V
-H-V