Artifact color - Atari 7800 emulation

[Tidus79001]

Is color artifacting possible to emulate?  If so do an of the Atari 7800 emulators have this as a feature?  Just curious if this is possible for a game such a Tower Toppler since it made use of artifacts color.  Emulation drastically changes the look of the game for the worse.

[Trebor]

9 minutes ago, Tidus79001 said:

Is color artifacting possible to emulate?

Yes.

9 minutes ago, Tidus79001 said:

If so do an of the Atari 7800 emulators have this as a feature?

A7800.

10 minutes ago, Tidus79001 said:

Just curious if this is possible for a game such a Tower Toppler since it made use of artifacts color.  Emulation without CRT artifacting drastically changes the look of the game for the worse.

FTFY.

[Tidus79001]

8 minutes ago, Trebor said:

Yes.

A7800.

FTFY.

@Trebor

Can you tell me how to enable color artifacts in A7800?  I looked at the video settings and didn't see anything obvious that said artifacts ( am sure it isn't only be default as my screen in Tower Topper doesn't look anything near that in A7800).  Tried searching on how to do this but couldn't find any details on it.  I am sure it snit difficult to do but I am just not finding how to do it.  If you could tell me how to enable it it would greatly appreciate it.  Thank you!

[Trebor]

From the A7800 manual:

 

The key takeaways are having "bgfx" set under the 7800.ini file for "video" option, and then with the emulator running, leveraging "hlsl" effect will give you options:

"Enable Adjustments" should be "On" and "Enable NTSC" should be "On".

 

It is most definitely not the most user friendly, and as advised in manual:

 

This is a feature inherited from MAME, for better and worse.

 

For me, it is definitely worth the effort and time.  It gives the experience a much closer to actual CRT feel:

[Tidus79001]

Thanks!  It looks amazing now.

[Trebor]

4 hours ago, Tidus79001 said:

Thanks!  It looks amazing now.

Awesome!  Glad to read that

 

Depending on your preference, and if you're feeling really adventurous, you can tweak the various settings to obtain an output anywhere from 'Poor RF' to 'Excellent S-Video'.

 

If you're shooting for excellent S-Video, it's easier and cleaner to go with "crt-geom-deluxe', instead of 'hlsl' as the effect. Though, as with original hardware, utilizing S-Video, you'll lose the artifacting needed for Tower Toppler. 

 

I recommend turning down the "Shadow Mask Amount" when using "hlsl", or "Shadow mask strength" when using "crt-geom-deluxe", to brightening things up a bit.

 

Here's a quick example of "crt-geom-deluxe":

 

Lock-in any changes permanently by editing the respective *.json file under the chains folder (I.E. A7800\bgfx\chains\crt-geom-deluxe.json)

 

File can be edited with anything as simple as Notepad, or something more robust, like Visual Basic.

 

Here's a comparison of effect HLSL and CRT-GEOM-DELUXE leveraging video bgfx.

 

Click the respective image to blow up bigger for better distinction between the two.

[+-^CrossBow^-]

There seems to be an issue with the emulation hardware accelerated drivers and nVidia cards I'm guessing? Because all other modes work great but as soon as I enable HLSL mode, the entire thing comes to a crawl with less than a frame per second and totally unplayable. Audio is also skipping and general messed up in this mode for me?

 

@Trebor what hardware configuration do you advise to run A7800 in HLSL mode properly then?

 

[Trebor]

 

9 hours ago, -^CrossBow^- said:

There seems to be an issue with the emulation hardware accelerated drivers and nVidia cards I'm guessing? Because all other modes work great but as soon as I enable HLSL mode, the entire thing comes to a crawl with less than a frame per second and totally unplayable. Audio is also skipping and general messed up in this mode for me?

 

@Trebor what hardware configuration do you advise to run A7800 in HLSL mode properly then?

I utilizing a NVIDIA GeForce GTX 1660 Ti without issue.  Driver Date: 1/15/2023.  Driver Version: 31.0.15.2824

 

Additionally, I've had this system for a few years, have kept up with all updates, including different drivers, and never experienced an issue.

 

For your system specifically, it may be a driver issue, or perhaps something else.

 

Just to be sure what is being leveraged under a7800.ini is...

 

 

...and not:

 

The "hlsl" setting is set as the "Window 0, Screen 0 Effect:" inside the 'Tab' menu while A7800 is running. 

 

If "hlsl" is being used as the video driver itself under OSD VIDEO OPTIONS, instead of "bgfx", there is a much higher chance to experience performance issues and other system requirements need to be met.  For example, it requires DirectX 9.0c full redistribution (AKA "End-User Runtimes June 2010") to be installed, regardless of what may already be installed on the system.

 

Ideally, with bgfx as video, and effect to be hlsl, inside a7800.ini, it should appears as such under the respective sections:

 

 

Placing the pound/hashtag turns off utilizing the line, but does serve as a nice placeholder for a reminder of what has been used previously.  For example, I am currently utilizing the white.png shadow mask; however, the default, and what was leveraged previously, is slot-mask.png. 

 

The aforementioned "crt-geom-deluxe" can be utilized instead of "hlsl" as the screen chains (AKA "Window 0 Screen 0 Effect:").  Each screen chain has its own set of video tweakable options that will be listed inside the respective *.json file in the chains folder, permanently modifiable there, or temporary modified when tweak via the 'Tab' menu options while the emulator is running.

[+-^CrossBow^-]

I think it is an issue with newer nVidia drivers then. I've got an RTX 2070 installed along with a now 'old' i7 - 9700k CPU. All other modes seem to work great but the hlsl mode brings the entire emulator to a crawl. My CPU only reports about 20% usage with the emu running, but the GPU is showing 100% usage and all memory being used?! So yeah it must be something with the new drivers. But I don't typically downgrade my drivers unless there is a HUGE issue and this one doesn't quite qualify. But I will mess around with it a bit and see if there are any driver tweaks I can do outside of the emulator to help.

 

 

[MrMaddog]

Thanks for the hlsl settings, the game (and everything else) looks better.

 

Sadly, A7800/MAME doesn't save the video settings so here's what you need in the a7800.ini file:

#
# BGFX POST-PROCESSING OPTIONS
#

(All other settings)

bgfx_screen_chains        hlsl

 

And the hlsl.json file in the bgfx/chains folder should have these lines after the comments:

{ "type": "intenum", "name": "adjustments", "text": "Enable Adjustments", "default": 1, "max": 1, "min": 0, "step": 1, "format": "%s", "screen": "any", "strings": [ "Off", "On" ] },

{ "type": "intenum", "name": "ntsc", "text": "Enable NTSC", "default":  1, "max": 1, "min": 0, "step": 1, "format": "%s", "screen": "any", "strings": [ "Off", "On" ] },

 

Though the NTSC settings "should" be On by default...