Screen Centering in VGA Mode

rashohyo
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Screen Centering in VGA Mode

Unread post by rashohyo »

Is there a way to center the screen also in analogue mode?
Real Amiga also have this problem on lots of tv...it would be great to have an options for that
Thanks
kolla
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Re: Screen Centering in VGA Mode

Unread post by kolla »

http://aminet.net/package/util/boot/CenterScreen12

May not work with games though. There are also other tools that feature this.
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Re: Screen Centering in VGA Mode

Unread post by bbond007 »

Sometimes games are more centered to to right because if they were closer to the left sprites 6 & 7 would not be visible.
akeley
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Re: Screen Centering in VGA Mode

Unread post by akeley »

On hardware side, there are some cheap Extrons that can center horizontally, you can read about them here.

Some later Trinitron models also have a "RGB centering" option in the menu which does just that.
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NightShadowPT
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Re: Screen Centering in VGA Mode

Unread post by NightShadowPT »

I'm also trying to find the best solution for this, and I have mixed results depending on the resolution I use.

To play games, in a 4:3 LCD screen that supports 1280x1024@60Hz, connected through VGA, what video configs would you recommend?

Currently I'm using the following:

On the Mister.ini:

Code: Select all

[Minimig]
vscale_mode=1
video_mode=4
video_mode_ntsc=4
video_mode_pal=4
On the OSD Video Options:

Code: Select all

TV Standard: PAL
Scandoubler FX: OFF
Video Area by: BLANK
Aspect Ratio:Original
I also use the Scale Filter "Scanlines (Bright Sharp)" because I like scanlines, but it is not needed.

To my eyes, this gives me a correct aspect ratio with clean scanlines, but unfortunately the screen is a bit far to the right and that messes with my OCD.

Is this something that can be fixed in the Core? (i.e.: the current "Adjust Screen Position option" only distorts the image, does not move it around the screen).

Thanks
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NightShadowPT
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Re: Screen Centering in VGA Mode

Unread post by NightShadowPT »

Bumping it in case any of the new users can help :)

Also, I have no idea what I did (maybe pressed some wrong key) and now the Amiga "visible screen" is on the top-left of my monitor, and no longer to the right as previously mentioned.

Meaning, I have the same problem, but on a different location :).

EDIT: If I change the "TV Standard" in the menu from PAL to NTSC, the image is now on the bottom right...

Are there any specific settings you guys would recommend for this? (remember I'm using a 4:3 LCD, not a CRT).

Not being able to center the screen is really messing up with my concentration.

Cheers
MikkyTee
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Re: Screen Centering in VGA Mode

Unread post by MikkyTee »

I'm a new mister user, and recently i've just been setting up cores etc The amiga was one of the main reasons i wanted a mister, initially i used the vga on a crt, but honestly i think im getting a better picture and with the scanlines @25% it looks good to me on an old 17in 4:3 lcd with a hdmi to vga adataptor. The screen is centered and looks great with all the 8&16 bit computers etc. Maybe have a look at that? :)
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NightShadowPT
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Re: Screen Centering in VGA Mode

Unread post by NightShadowPT »

MikkyTee wrote: Wed Jan 06, 2021 11:06 am I'm a new mister user, and recently i've just been setting up cores etc The amiga was one of the main reasons i wanted a mister, initially i used the vga on a crt, but honestly i think im getting a better picture and with the scanlines @25% it looks good to me on an old 17in 4:3 lcd with a hdmi to vga adataptor. The screen is centered and looks great with all the 8&16 bit computers etc. Maybe have a look at that? :)
That may be a solution... I can even connect it to the same monitor in a different input...

Can you please share the details of your configuration? (Mister.ini)?

Thanks
ash2fpga
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Re: Screen Centering in VGA Mode

Unread post by ash2fpga »

If you are using the scaler, you may be able to adjust the hfp/hbp/vfp/vbp video_mode values to center the image.

Some discussions on the concept, although for different products/platforms:
https://retropie.org.uk/forum/topic/867 ... 666-to-pvm
https://shmups.system11.org/viewtopic.p ... 6&start=30
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Re: Screen Centering in VGA Mode

Unread post by MikkyTee »

NightShadowPT wrote: Wed Jan 06, 2021 2:43 pm
MikkyTee wrote: Wed Jan 06, 2021 11:06 am I'm a new mister user, and recently i've just been setting up cores etc The amiga was one of the main reasons i wanted a mister, initially i used the vga on a crt, but honestly i think im getting a better picture and with the scanlines @25% it looks good to me on an old 17in 4:3 lcd with a hdmi to vga adataptor. The screen is centered and looks great with all the 8&16 bit computers etc. Maybe have a look at that? :)
That may be a solution... I can even connect it to the same monitor in a different input...

Can you please share the details of your configuration? (Mister.ini)?

Thanks
I have not changed anything in mister.ini apart from enable scan doubler ;)
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NightShadowPT
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Re: Screen Centering in VGA Mode

Unread post by NightShadowPT »

ash2fpga wrote: Wed Jan 06, 2021 3:35 pm If you are using the scaler, you may be able to adjust the hfp/hbp/vfp/vbp video_mode values to center the image.

Some discussions on the concept, although for different products/platforms:
https://retropie.org.uk/forum/topic/867 ... 666-to-pvm
https://shmups.system11.org/viewtopic.p ... 6&start=30
That's interesting, thanks for sharing.

Is there anywhere on the Wiki where I can read what is the meaning of hfp/hbp/vfp/vbp? Cant seem to find it, and I dont know exactly what to use here.

Cheers,
ash2fpga
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Re: Screen Centering in VGA Mode

Unread post by ash2fpga »

NightShadowPT wrote: Sun Jan 10, 2021 4:34 am That's interesting, thanks for sharing.

Is there anywhere on the Wiki where I can read what is the meaning of hfp/hbp/vfp/vbp? Cant seem to find it, and I dont know exactly what to use here.

Cheers,
hfp=horizontal front porch
hbp=horizontal back porch
vfp=vertical front porch
vbp=vertical back porch

The front/back descriptor appears to be in relation to the respective sync signal, and not the on-screen image.

Here is a document illustrating from the on-screen image perspective (p. 12), and the signal perspective (p. 13): https://www.nxp.com/wcm_documents/techz ... logies.pdf
lordoftime79
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Re: Screen Centering in VGA Mode

Unread post by lordoftime79 »

Hi there - this is how Amiga is supposed to be, go check a Real Amiga, Go check a Vampire 4 Stand alone both dont have centered displays when displaying native chipset output.
ByteMavericks
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Re: Screen Centering in VGA Mode

Unread post by ByteMavericks »

The placement on the screen, as many above have said, was programmable... The fun of DIWSTRT, DDFSTRT, DIWSTOP and DDFSTOP - the horror.

It's a non-trivial thing to solve given programmers can and do shift them around: the joy of CRTs on a real Amiga is that once you've got it perfect for one screenmode, you can guarantee it'll be nearly unusable for another :)
Xtro
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Re: Screen Centering in VGA Mode

Unread post by Xtro »

Anyway would be interesting to have a centering option for VGA output on all cores, the same than jotego does for his arcade cores
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