MiSTer FPGA Forum

Sorry if this is a noob question but I haven't found tutorials for this. I'm pretty sure the MiSTer will be able to do the following but not many people seem to be doing it.

Is there a way to have the screen only be 2 or 3 times the original 240x160 resolution, instead of the default 5 times to fit the screen?
So having the core display at 480x320 or 720x480 but not stretch to fit the screen.
I've only managed to tinker with the integer scale option, that maintains aspect ratio but still fits most of the screen.

Many games for the GBA had 3D-inspired graphics converted to pixels, and I hate how they look when resized full-screen. Was just playing Altered Beast: Guardian of the Realms and it would be cool to have it only show up 2x or 3x instead of 4.5x or 5x where it fills the screen.

Huge thank you in advance for any pointers!

You can experiment with vscale_border and setting it to a rather large value to achieve what you want.

Yeah the formula would be:

(video_mode resolution - target resolution)/2 = vscale_border setting

So if you’re on 1080p and you want it scaled up 3x, it’s

(1080 - 480)/2 = 300

In mister.ini:

[gba]
vscale_mode=0
vscale_border=300

Giving 300 blank lines above, 480 lines of picture, then 300 blank lines below. For 2x scaling you’d need it set to 380. The vscale_mode setting is only necessary if your universal vscale_mode is something other than zero - the border setting seems to be disabled if integer scaling is enabled in the ini.

Thank you so much Rhester72 and Yim!
Yes, changing vscale_border worked like a charm.

Yim, it's weird but vscale_border=300 leaves the screen extremely small, at what seems like the original resolution.
vscale_border=150 looks like 3x scaling.
But I can't figure the ratio, I didn't manage to get something resembling 4x.
100 and 50 don't give me the size I would expect, and 10 is obviously almost the default size, 6x.

I created MiSTer.ini and appended at the end:
[GBA]
vscale_border=150

So only the GBA core is rendered smaller. (I'll probably do it for the Game Gear too when I figure out the numbers.)
So cool, I don't even need to manually specify to use MiSTer_alt_1.ini.
(EDIT: dang, you actually had already told me to specify [gba] but I started making changes enthusiastically to Mister.ini without noticing that part. My bad. Thanks again, Yim.)

The MiSTer certainly doesn't disappoint.

What’s the resolution of your screen and your video_mode setting? If you’re on the default video mode setting then the mister will be putting out 720p and a 300 pixel border would only leave 120 pixels for the actual image, maybe that’s why it was so tiny for you?

The game gear’s resolution is 144 lines instead of 160, so you should get similar results by adding (8 x scaling multiple) to the border size you’re using on GBA.

@Yim and @Vinicius,

GBA is 160px tall, 3x is 480, so (assuming a standard MiSTer 720p output) you'd want a vscale_border of 120 [(720 - (160 * 3)) / 2] for 3x integer (vertical) scaling.

Thank you SO much.
(Sorry for the late reply, was crazy busy.)

Noob mistake, I had assumed the default output for the MiSTer was 1080, nope. But I changed it now, video Mode 8. Now the GBA is running at glorious 4x scaling.

And I set the Game Gear to 4x too.
Since the GG shares the core with the Master System, I'm using the MiSTer_alt_1.ini to switch borders when I want to play GG. I'll have to study sometime how I can use MRA to automate that, or compile the core to split the Game Gear into an identical but separate core: viewtopic.php?t=1782
I did try using a fork (Antonio Villena's) but it's recognized as the same Master System core.
Anyway, no biggie, thanks again.