RE: ISA Vector card already done...

> > 1) the settling of the deflection amps can make the line "squiggly"
> at
> > the end
>
> Probably not, but the slowing down will cause increased brightness
> at the end. That's why Cinematronics targets a point way beyond the
> real end of the vector and then stops - the speed is more constant
> if you only draw for a portion of the charging time.
>
Well, something's causing it. :-) This is based on testing on a WG6100
monitor. This probably has more to do with the settling of my output
hardware though now that I think about it, so it's probably not the
monitor's fault. (I vaguely recall being able to "fix" it before on my
board.)

> > 2) the line might not travel in a completely straight line (a short
> > vertical deflection will reach "point B" faster than the long
> horizontal
> > deflection, so your "line" will be "L" shaped)
>
> That'll only happen if the R/C constant for X & Y are different.
> Remember,
> an RC circuit will reach the half-way point in a fixed amount of time,
> so
> if X and Y have the same RC constant they will both reach 1/2 way to
> the
> destination at the same time (also 1/4 of the way and any other
> fraction).
> That's why the components are high tollerance, any variation will
> cause
> curved vectors and the L shape clay speaks of. This combined with the
> critical timing of turning the beam off (cinematronics) is probably
> why
> Zonn can't get the vectors to line up perfectly.
>
Once again, my comment was based on direct observation while using the
WG6100. I was driving the Sega G-80 hardware with the color guns
hardwired "on" and jumping to new locations (seeing what the monitor
would do). So this is just a new X and Y Voltage instantly appearing
and seeing what the monitor "draws" to get to the new point. No other
integration hardware involved other than the behavior of the deflection
amps. I'd suspect it varies from monitor to monitor too...

-Clay
Received on Thu Mar 26 08:20:33 1998