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Monitor Stuff

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Monitor Problem:

When I heard that the video output wasn't right, I assumed it was too low. 

Rick Meyette says the problem is that the Stun Runner board produces Too Much
video output voltage for the Sanyo Monitor. 

The way to fix it is to install the 3.3K resistors at R97, R108, and R112.
Heretofore they were not loaded in order to boost the video output.

With these resistors loaded, the maximum video output should be 3.0 volts.
If it isn't we will adjust the value of the resistors until it is.

There may be a problem with threshhold brighness values. To wit:

		Wells-Gardner		Sanyo
		-------------		-----			
Max Video	3.5 Volts (255 DAC)	3.0 Volts (255 DAC)
Gray		1.5 Volts (85 DAC)	1.5 Volts (102 DAC)
Threshhold	1.0 Volts (42 DAC)	1.0 Volts (51 DAC)
Min Video 	0.5 Volts (0 DAC)	0.5 Volts (0 DAC)


The Sanyo cannot be adjusted to work with Wells-Gardner video levels.
Meyette say the Wells can be adjusted to work with Sanyo levels. I suggest
we use Sanyo levels.

Let's plan on adding the resistors to a board and connecting it to a
Sanyo monitor. It may be necessary to adjust the gray levels in software.


	Jed
Message 1 of 1

Apr 12, 1989