VECTORLIST - The Mailing List For The Technical Discussion of Vector-Based Arcade Games

November_1999
RE: Vector Hardware


From: Clay Cowgill ( )
Date: Fri Nov 12 1999 - 13:36:17 CST


> What is the DAC08 doing in the circuit? So far as I can see from the
> schematics
> and MC1495 datasheets, it seems to me that the MC1495 multipliers perform
> the
> east-west correction (pincushion).
> As you can see from the circuit, the output current of the DAC08 is
> directly
> summed to that of the XY DACs.
> Maybe somebody could shine a light here? I am really trying to know how
> the AVG
> functions exactly...
>
That should perform the drawing scale control. (It varies the reference
voltage, which in turn results in the amplitude of the output from the 10 or
12-bit DACs changing. Smaller reference voltage = smaller output amplitude
= less deflection = smaller image on screen.

-Clay


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