Re: multi-game proto board

At 05:02 PM 5/2/97 -0800, you wrote:
>>So have you tried this? And all you get is the pincushion effect? No
>>problem with filling the entire monitor with vectors? That would make life
>>easier. Maybe the Sega Vector systems aren't using the full speed
>>capabilities of the GO-8 monitors. That would be nice.
>
>I haven't tried it myself-- others have though and the "distortion" effect
>was limited to an occasional miss-placed vector. You could probably drive
>the deflection section a little harder, or more likely just live with it.
>;-)

Well given the limited amount of current available with the +/- 25v supply,
how fast you can "charge" (for lack of better word) up the inductor is just
a matter of physics. The inductors act like a resistor while it's in a
state change. And given a fixed resistance (or in the case of the inductor,
reactance) value, the 25 volt power supply limit, limits the maximum current
available. For a stronger magnetic effect on the beam you need more current
through your yoke.
Driving it stronger will just cause it hit maximum speed a little faster.
It won't allow you to move the beam any faster than the maximum 25 volts
will allow. You end up with a current curve (if graphically mapped) that
looks like a clipped sawtooth wave. That harder you drive it, the steeper
to slope of the sawtooth, but it's still going to clip at the same place.

(This description is not directed towards you, Clay, but to others that may
be following this thread.)
 
But from your following explanation it might not be as big a deal as I
thought it was...

<explanation clipped, go back and read it though, a good description of the
vector system>

>The only "gotcha" as far as the slew rate is concerned when using it with a
>Wells Gardner monitor is parallel loads on the counters to the DACs.
>(Those can make a big deflection fast when the new position is latched in.)
>Otherwise, the max vector slew rate looks to be something the WG monitors
>can handle OK.

<more data clipping>

So it sounds like the real problem is how fast they move to a new screen
position to start a new vector. That explains the misplaced vectors.

So you can live with misplaced vectors, or crank up the voltage on the WG,
or (this might be the hardest, I guess) find yourself a GO-8 monitor (and
uh, fix it since you know it's going to be broken).

-Zonn
Received on Fri May 2 17:47:25 1997