Rastergraf Topaz, User Manual

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Rastergraf
5-14 Programming On-board Devices and Memories
5.4.1 Application Note: Adjusting the Timing Parameters
Most monitors have adjustments for Horizontal Frequency, Horizontal
Position, Horizontal Size, Vertical Frequency, Vertical Position and
Vertical Size. It is recommended that the monitor adjustments be tried
before trying monitor settings not in accord with the monitor data sheet.
Rastergraf’ SDL software allows you to define the timing parameters in
one of two ways:
a) you tell SDL that you are using a multiscan monitor. You specify the
display active width and height (e.g., 1600 x 1200) and the Vertical
Frequency, and the program figures out the rest.
b) you tell SDL exactly what you want the timing to be. You specify:
•
vertical frequency in Hz
•
vertical blanking in milliseconds (ms)
•
vertical front porch in ms
•
vertical sync width in ms
•
horizontal blanking in microseconds (us)
•
horizontal front porch in us
•
horizontal sync width in us
•
display width and height
•
The program derives the horizontal frequency from this information.
Ordinarily, you should be able to use the monitor’s data sheet to obtain a
satisfactory display. However, it may be that adjustments are required.
This section gives you some advice on how to do this. You can also send
Rastergraf a filled-in copy of the parameters sheet which follows this
section.
Declaration
Rastergraf is dedicated to making your application work. We can assist in
determining special video timing parameters for specific monitors and
other output devices. If you need help it would be very useful if you can
gather the data requested in the following form before calling us.