GroovyMAME on PDP-V402

[nakedarthur]

First off, thanks so much for GroovyMAME Calamity! I've been using it for a couple months now on a PVM and consumer CRT and it's really incredible.

I recently ran into a Pioneer PDP-V402 locally, and always hearing they're great for shmups I went ahead and grabbed it. It's a unique plasma screen in that it has a 4:3 native 480p resolution, accepts both VGA and RGB sources, and features a linedoubler for 15khz sources with no input lag (from what I can tell).

Most games run perfectly on it, but I'm having issues with a few that run at lower refresh rates like Mortal Kombat, DonPachi, R-Type, Raiden II, etc. On these games the TV gives me a "Out of Range!" error. Interesting enough, if I replace DonPachi's modeline with the one from Mushihimesama that runs at 60hz, it works fine (aside from some seemingly juddery scrolling).

I guess my question is two fold. One, is there a tool you recommend where I can easily generate compatible modelines so I can incrementally lower the refresh and see where its giving out? Second, Fudoh over at shmups said it may be more lenient with VGA signal, and to try possibly linedoubling in MAME for a 480p signal and outputting at 31khz. Is that something GroovyMAME is capable of?

Thanks!

[nakedarthur]

Quick update: I went into VMMaker.ini, changed display type to VGA, re-ran it, rebooted computer, then in mame.ini I changed the display type to arcade_31. I'm now able to run DonPachi, DodonPachi, and ESP Ra.De double scaled at 57.5hz! Unfortunately some other games like Mortal Kombat and Raiden still aren't working. I just saw the option for LCD panel and custom frequency ranges, so I guess I will try that next.

There's something strange I noticed when I was testing though. After the computer restarted from VGA VMMaker changes it defaulted the desktop to odd resolution like 640x768. If I run Groovymame when set to that desktop res I get perfect double-scaled at original refresh rate. However, I wanted the desktop to be a normal 640x480, and after I changed it with ArcadeOSD, DonPachi began detecting at 640x512@60hz instead of 640x480@57.5hz. Any idea why it'd do that?

[haynor666]

From here http://shmups.system11.org/viewtopic.php?f=6&t=43256 I read that might not work with PAL singals (if You are in USA) so anything below 59 Hz might not work.