Slightly tilted XY Gravitar Monitor and Dragon's Lair timing issue

John566

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Slightly tilted XY Gravitar Monitor and Dragon's Lair timing issue

I'm thinking about picking up a few games today and was hoping to get a bit more insight into how hard these issues may be to fix.

Gravitar:
-The picture looks bright and very colorful but it is slightly tilted. Can I fix this by rotating the deflection coil a little bit? How much do I risk messing up the convergence?
-The Gravitar occasionally boots so that the image is fairly distorted; hard to describe. Turning it off and back on seems to fix the problem. Any ideas how serious this is?
-My memory of XY vector games is that the lines were very sharp lines. This Gravitar, and a Space Duel I'm also considering, both look fairly jagged almost like raster graphics. Is my memory wrong or is there something wrong with the machines? Looking at razor sharp resolutions on phones and tablets the last few years has likely spoiled me.

Dragon's Lair/Space Ace
-This cabinet is a Space Ace that I believe was converted from a DL (blue art). It comes with both Laser Disks and the circuitry to work with both. When the gentleman who demoed it for me yesterday was playing it, the game seemed to kill him when it shouldn't have. I know that DL's timing can be tricky and maybe he was off but I wanted to make sure this wasn't something to watch out for (input timing being off).

Thanks to any and all input!
 
Gravitar:
-The picture looks bright and very colorful but it is slightly tilted. Can I fix this by rotating the deflection coil a little bit? How much do I risk messing up the convergence?

If you don't move the yoke forward or backward at all when you loosen the clamp to rotate it, you minimize (but don't eliminate) the risk.

-The Gravitar occasionally boots so that the image is fairly distorted; hard to describe. Turning it off and back on seems to fix the problem. Any ideas how serious this is?

Clean legs of socketed chips as first step.

-My memory of XY vector games is that the lines were very sharp lines. This Gravitar, and a Space Duel I'm also considering, both look fairly jagged almost like raster graphics. Is my memory wrong or is there something wrong with the machines?

B&W games are razor sharp because the phosphor coating on the tube is continuous. The phosphor coating of color tubes is divided into RGB trios so, for example, a red line will be interrupted by the unlit green and blue phosphors. Medium res Amplifone tubes have smaller trios packed closer together than WG6100 tubes and will therefore have sharper, more solid-looking lines. Best case is a diagonal line; worst case is a line that is just a few degrees away from being vertical (or horizontal). So fixing the tilt may help with the jaggies/stairsteps.
 
-My memory of XY vector games is that the lines were very sharp lines. This Gravitar, and a Space Duel I'm also considering, both look fairly jagged almost like raster graphics. Is my memory wrong or is there something wrong with the machines? Looking at razor sharp resolutions on phones and tablets the last few years has likely spoiled me.

When I converged the WG6100 on my Tempest I found that if you focus the image as tightly as possible the lines will always have a jagged appearance as they cross the curve of the screen (this seemed esp. true on the horizontal lines). You will also make it nearly impossible to get a perfect convergence as the overlap of the 3 colors becomes razor thin.

I found that by defocusing the monitor just a bit the convergence was much better and the lines looked full and solid instead of jagged. YMMV but if you are seeing lots of jaggies it might be worth a try.
 
When I converged the WG6100 on my Tempest I found that if you focus the image as tightly as possible the lines will always have a jagged appearance as they cross the curve of the screen (this seemed esp. true on the horizontal lines). You will also make it nearly impossible to get a perfect convergence as the overlap of the 3 colors becomes razor thin.

I found that by defocusing the monitor just a bit the convergence was much better and the lines looked full and solid instead of jagged. YMMV but if you are seeing lots of jaggies it might be worth a try.

Seconding this, I back off the focus a hair on all color vectors and it makes for a great looking image.
 
I was able to rotate the Gravitar's picture by loosening the bolt and rotating it a tiny bit. I also defocused the Gravitar and Space Duel slightly and that really helped. The Gravitar has been behaving lately but I'll give the leg cleaning a shot if it starts do distort the graphics again. Thanks for all the great feedback!
 
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