MiSTer FPGA Forum

Posted: **Fri Feb 18, 2022 9:33 pm**

Hi all!

I'm using my MISTer on my Lg Studioworks 700S Svga that has a max resolution of 1280 x 1024 / 60Hz.

I'm trying to "perfect" upscaling Commodore 64 core with scanlines. These are the settings on .ini:

Code: Select all

[MiSTer]
key_menu_as_rgui=0     ; set to 1 to make the MENU key map to RGUI in Minimig (e.g. for Right Amiga)
forced_scandoubler=0   ; set to 1 to run scandoubler on VGA output always (depends on core).
ypbpr=0                ; set to 1 for YPbPr on VGA output.
composite_sync=0      ; set to 1 for composite sync on HSync signal of VGA output.
vga_scaler=1          ; set to 1 to connect VGA to scaler output.
[c64]
# 320×200; The C64 has a resolution of 320×200 pixels, consisting of a 40×25 grid of 8×8 character blocks.
vscale_mode=0
video_mode=1280,72,136,208,800,2,6,50,87410

Now, the Commodore has a native resolution of 320x200px, so multiplied by 4 is exactly 1280x800px.

I've set it but, both in vscale_mode=0 or vscale_mode=1 it doesn't fit the screen and/or displays correctly the scanlines, as from pictures below why?

: IMG_3441.jpeg (114.33 KiB) Viewed 1573 times

: IMG_3442.jpeg (133.19 KiB) Viewed 1573 times

Posted: **Fri Feb 18, 2022 9:50 pm**

it will be pixel perfect when you set CROP to on. works perfect with many games.
unfortunetely some games have different resolution and they will be cut at the top and bottom of the screen :/

Posted: **Fri Feb 18, 2022 9:55 pm**

xFlesk wrote: ↑Fri Feb 18, 2022 9:50 pm it will be pixel perfect when you set CROP to on. works perfect with many games.
unfortunetely some games have different resolution and they will be cut at the top and bottom of the screen :/

Yes, it worked! There is a method to set the video_mode "per game" like I know it's possible in Minimig - Amiga viewtopic.php?f=4&t=2227 ?

Thanks!

Posted: **Fri Feb 18, 2022 9:56 pm**

The 320*200 is the number of pixels within the border. If you display the whole border the screen resolution the MiSTer needs to display is 384*272.

Posted: **Fri Feb 18, 2022 10:13 pm**

xFlesk wrote: ↑Fri Feb 18, 2022 9:50 pm it will be pixel perfect when you set CROP to on. works perfect with many games.
unfortunetely some games have different resolution and they will be cut at the top and bottom of the screen :/

Sorry, my mistake in the reply. It works, I don't know why, in 1280x1024@60, with CROP on 1280x800@60Hz all the borders are cropped out...

Posted: **Fri Feb 18, 2022 10:14 pm**

Chris23235 wrote: ↑Fri Feb 18, 2022 9:56 pm The 320*200 is the number of pixels within the border. If you display the whole border the screen resolution the MiSTer needs to display is 384*272.

So what is the resolution for a perfect scale? I've tried this strange resolution, 1152x816 (that is 384*272) and it seems to work...
video_mode=1152,64,120,184,816,1,3,25,77060

Posted: **Fri Feb 18, 2022 11:01 pm**

So this may not be the perfect solution, but I've had good results.
I just use multiples of the generic PAL or NTSC resolutions of 720x576 and 640x480 respectively and using vscale_mode=1.
So in your case, your monitor maxes out at 1280x1024 at 60Hz, so it might be able to swing 1440x1152 at 50Hz.
If not, you could do 1152x864 which would give you a 3X for the C64 with maybe a smidge of a border.

The caveat to this is, you will still need some horizontal interpolation filtering since it will only be pixel perfect on the vertical axis.

Given that it's a CRT monitor, have you tried using the scandoubler instead of the VGA scaler?

MiSTer FPGA Forum

Commodore 64 4x "perfect scaling" doesn't work

Commodore 64 4x "perfect scaling" doesn't work

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Re: Commodore 64 4x "perfect scaling" doesn't work

Re: Commodore 64 4x "perfect scaling" doesn't work

Re: Commodore 64 4x "perfect scaling" doesn't work