GBA Core and BVM Question

[slai50]

For those who are using mister with BVM monitors, if you run GBA core on a mister connected to a BVM-20F1U, will there be black borders around the picture or will it be full screen?

[Atohmdiy]

I just finish metal slug advance with my mitser in direct video and my BVM-20F1E
In direct video you get a small image as it is in gba native resolution. You need the scaler to get something full screen but as gba resolution is not a multiple of the standard 320x240 res you are not suppose to end up with something great.

[slai50]

When you say scaler do you mean something like the OSSC?

[Peredonov]

The MiSTer has a scaler function that can work for the "VGA"/analogue output just as it works on the HDMI digital output. But if your monitor is not multisync the scaled output may not be displayable on it.

[Sigismond0]

GBA has a resolution of 240x160. So native display will take up about 2/3 the height of your screen and 3/4 the width (approximations here). If you want it to take up the full width, you'd need to enable the scaler as mentioned. But you can't just double it, because 480x320p is too large to display on a 15khz display. You'll have to do a 1.25x or 1.5x scale, and that leaves you with uneven pixels and a very bad image overall.

Anyway, if you want to see what it looks like with the scaler enabled, try adding this to your ini file:

[GBA]
video_mode=320,8,32,24,240,4,3,16,6048
vga_scaler=1
vsync_adjust=2
vscale_mode=0

Edit: If you have a multisync display, someone else has posted these settings, which should be integer scaled and near fullscreen:

[GBA]
video_mode=856,40,80,120,642,3,4,19,43750
vscale_mode=1
vsync_adjust=2

[Brettster]

Do those only work with a BVM / PVM? when I try the first one on a 15hkz CRT TV, I see the start up image briefly appear then it goes out of sync

[Sigismond0]

I've used the first one personally, and it works fine on my PVM-20M2MDU. Doesn't look great, but runs just fine. That's copied directly out of my alt ini, and I just used it yesterday. Can't speak for the second, as my PVM isn't multiformat.

[Brettster]

Thanks, I guess its just my generic TV that doesn't like it

[Sigismond0]

Interesting. If I recall correctly, I had initially used those settings on a consumer Trinitron set so I'd expect them to work there, too.

[tekn0]

Anyway, if you want to see what it looks like with the scaler enabled, try adding this to your ini file:

[GBA]
video_mode=320,8,32,24,240,4,3,16,6048
vga_scaler=1
vsync_adjust=2
vscale_mode=0

Edit: If you have a multisync display, someone else has posted these settings, which should be integer scaled and near fullscreen:

[GBA]
video_mode=856,40,80,120,642,3,4,19,43750
vscale_mode=1
vsync_adjust=2

I have tried adding both of the settings to my INI file, but unfortunately neither setting does anything. I notice no change at all. Tried rebooting the Mister but nothing seems to matter.

I am using direct video on a CRT over component. Am I missing a step?

[FoxbatStargazer]

Replace vga_scaler=1 with direct_video=0. You need to turn OFF direct video to use custom resolutions.

That means you also might need to greatly increase the horizontal resolution to satisfy HDMI requirements for your adapter. (use aspect ratio = full to get something usable, albeit imperfect.)

[Optiroc]

You can also use one of the alternative geometry slots on the monitor (overscan or 16:9) and set it up to massively underscan. You will probably not reach full screen, but you might get close. Also, the scanline separation will be pretty extreme.