Modeline creation for NeoGeo on a trinitron-style CRT screen

[bilippe]

Hi,
I am looking to create a Modeline for Neogeo. Indeed, the image is a little stretched horizontally and some fighting games display life bars which overscan ...
I have a modeline available and the overscan is more or less corrected but the H display is not really centered and above all I have a horizontal strip at the bottom of the screen ...
For connoisseurs: can help me correct this modeline to have a perfect display on a trinitron style CRT screen please?
Thank you in advance for your help
I join you my ini with the modeline at the bottom of the ini

video_mode=320,7,28,29,224,16,8,16,6000

[marcof]

Hi, attached the my .ini files (https://we.tl/t-7YkYU3RE6X). Main is 6x integer scale, alt_1 is 5x integer scale (https://github.com/atrac17/MiSTer_Integer_Modelines).

It's simply amazing. I use it with dual output (Sony Trinitron CRT through the VGA output with an RGB/Scart cable) and a standard HDMI monitor output.

My preferred way to play is the CRT, but the HDMI output (6x or 5x integer scale) is amazing also. Big shoot-out to atrac17. Amazing work!

Give it a try.

Cheers,

MF

[FoxbatStargazer]

The idea here is to create a modeline for SD CRTs, so you can view the side overscan and see the full 320 pixels...

I would try using 240 height (along with vscale_mode=1)

[akeley]

@bilippe, you can try to use the modeline calculator to tweak the one you have posted in my thread: https://www.epanorama.net/faq/vga2rgb/calc.html
and follow some tips from this thread: viewtopic.php?p=29674#p29674

The author of this post, @thorr would most likely have more to say on this subject.

Hope you guys can cook something up, though it's not that crucial in this case (only about 1cm wide band of detail is lost both left and right). Myself, I'm just playing games and staying away from the CRT-tweaking rabbit hole, for a little bit at least

[rgavril]

This is what I use and I get a centred image with little to no overscan.

Code: Select all

[NEOGEO]
video_mode=320,21,29,44,224,13,14,13,6400
vga_scaler=1
vsync_adjust=2

I play NES a lot and the video_mode is customized so it matches the default NES output in terms of H/V centring, but if the image is not centred on your screen you can try playing with this parameters:

Horizontal Front Porch (hfp) / Horizontal Back Porch (hbp) : To move the visible area horizontaly
Vertical Front Porch (vfp) / Vertical Back Porch (vbp) : To move the visible area vertically

Code: Select all

video_mode=320,hfp,29,hbp,224,vfp,14,vbp,6400

As long as the sum of this two values doesn't change, the new video_mode will be valid and will display correctly.

Code: Select all

 
  ; ORIGINAL Video Mode
  ; video_mode=320,21,29,44,224,13,14,13,6400
  ; hfp + hbp = 21 + 44 = 65 
  ; vfp + vbp = 13 + 13 = 66
  
  ; NEW Video Mode
  ; This example pushes the vertical area all the way to the top left of the screen
  video_mode = 320,0,29,65,0,14,66,6400

If you think it sounds complicated, I think this image will make it easier to understand:

vga_regions_1.png (12.76 KiB) Viewed 11103 times

[akeley]

Can confirm that using this modeline the overscan is gone. If you're using Direct Video you need to disable it though.

[Pepeart]

Hi, I tested "rgavril" and it works almost perfect on my pvm.I now have a 1/4" gap on the right side of my screen ( when Im facing the screen ) Can some please tell me wich two digits to change to get rid off the gap on my screen? Thank you
[NEOGEO]
video_mode=320,21,29,44,224,13,14,13,6400
vga_scaler=1
vsync_adjust=2

[rgavril]

@Pepart:

First try decreasing the hfp, hbp values, this will give you a bigger horizontal visible area:

Code: Select all

video_mode=320,21,29,34,224,13,14,13,6400

Then push the image to the left / right to re-center it by incrementing / decrementing hfp, hbp values:

Code: Select all

video_mode=320,15,29,40,224,13,14,13,6400

It's hard for me to come up with the best values for your screen, you'll need to experiment and see what works for you.

[Pepeart]

Got it. Thank you for your help

[bilippe]

6400 is a correct value for pixelclock??
NG has a 6.00Mhz pixelclock (6000), isn't it?

[Fed]

Can confirm that using this modeline the overscan is gone. If you're using Direct Video you need to disable it though.

What problem does it cause to use it with direct_video ?

[akeley]

I can't remember exactly but probably was refering to the fact that modelines don't work with DV in general.