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Main => Monitor/Video Forum => Topic started by: snappleman on August 26, 2016, 06:18:24 am

Title: Input Lag/sync/scanlines running GroovyMame on a PC CRT monitor
Post by: snappleman on August 26, 2016, 06:18:24 am
Hi everyone, I asked this question on another forum and got some nice info which directed me here. This place is amazing and I spent the last few days reading as much as I could but it's just so much to take in (and I'm not very technical...) so I'm a bit overwhelmed with the info.

Basically what I want to do is use an old PC VGA CRT monitor (Dell D1728D-LS SVGA monitor) for GroovyMame. I have an ATI HD2400 and HD5450 lying around that I can install CRT_emudriver on, but I have a few questions about what's possible with this setup:

1) Can I get a VGA CRT to sync at 15khz? Is this model dependent or simply impossible for these monitors?

2) Can I expect improved input response over an LCD when using a VGA CRT at 31khz + vsync?

3) Is it possible to get low/native Mame resolutions at 31khz (if the monitor can't sync to 15khz)?

I remember being into (buggy) emulation back in the mid/late 90s with nesticle, MAME and NeoRage and playing side by side with my consoles and going to arcades, and I didn't notice any difference in the input lag, but I really don't want to go building a new rig and getting old hardware out of storage just to find out that I'll have similar issues to using an LCD.

Anyway, thanks to everyone here for creating/contributing to this great place, and extra thanks to anyone who offers me some advice :D!

Title: Re: Input Lag/sync/scanlines running GroovyMame on a PC CRT monitor
Post by: SailorSat on August 28, 2016, 03:45:38 am
1. Most newer VGA monitors start syncing at about 27kHz, so no 15kHz.

2. I would think so.

3. doubling the framerate / drawing each frame twice will double the frequency - but you will have MASSIVE scan lines, as the VGA tube has a much finer dot pitch.

(http://images.arianchen.de/tn_step-320x240-120.jpg) (http://images.arianchen.de/step-320x240-120.jpg)
Title: Re: Input Lag/sync/scanlines running GroovyMame on a PC CRT monitor
Post by: snappleman on August 28, 2016, 04:59:25 am
Thanks for the reply!

When you say "newer" I assume you mean mid 90s and up, right? This one is from around 1995 so I assume 15khz is out. Honestly being able to sync at 15khz is much less important to me than having good control response and no screen tearing.

I started reading the forum backwards since I figured these questions were more common in 2003, and I did learn a good bit more. Having better response and better colors along with a 4:3 aspect ratio with no black bars around an LCD is probably going to be enough for me.

If the double frequency scanlines are too distracting I assume I can run the games at higher resolution and sync MAME's refresh rate to the monitor (disabling throttle) and then just using a shader for the scanlines? Or do I have that process wrong?