GBA Core porting to Mister

[ReedSolomon]

(except for games with special hardware)!

Well, at least in theory rumble and tilt could be possible using something like a wii remote or switch pro controller. Is there other special hardware to consider?

[FPGAzumSpass]

There seems to be an issue with Shader Colors on VGA CRT (maybe also on VGA & 15Khz CRT?).
For example playing Mario Kart on the main menu picture it shakes. If I change Shader Colors to something else than OFF the shake goes. But then when I go into the next screen it starts shaking and I have to select Shader Color; OFF. Then when I get into a race the screen shakes again so I have to select Shader Color: Something else than OFF.

Please be sure to set "Sync core to video" to "On".

The switch of shadercolor does alter the draw timing by 50 ns at the time you switch, but i doubt that is the reason for this effect.

[Peredonov]

(except for games with special hardware)!

Well, at least in theory rumble and tilt could be possible using something like a wii remote or switch pro controller. Is there other special hardware to consider?

Yeah I thought about that possibility. Would be great to play some WarioWare!

There's the Boktai games with sunlight sensor, they're pretty neat. I imagine there could be a way to emulate bright/dark detection, and maybe steps in between. For the RTC games, we do have RTC daughter boards but there's probably a reason why these are not being used for that.

I found what may be a complete list here: https://www.reddit.com/r/Gameboy/commen ... ames_that/

[FPGAzumSpass]

For the RTC games, we do have RTC daughter boards but there's probably a reason why these are not being used for that.

Yes, the reason is nobody implemented the GBA side accessing it yet

[ReedSolomon]

(except for games with special hardware)!

Well, at least in theory rumble and tilt could be possible using something like a wii remote or switch pro controller. Is there other special hardware to consider?

Yeah I thought about that possibility. Would be great to play some WarioWare!

There's the Boktai games with sunlight sensor, they're pretty neat. I imagine there could be a way to emulate bright/dark detection, and maybe steps in between. For the RTC games, we do have RTC daughter boards but there's probably a reason why these are not being used for that.

I found what may be a complete list here: https://www.reddit.com/r/Gameboy/commen ... ames_that/

Perhaps sunlight data could be assigned to a button. More sunlight=y, less =x, and the core then reads that value? Unless there's some sort of actual light sensor on the de-10 nano that could be used. Seems like a sillu gimmick though. Maybe press x and then use the D-pad to move a light vs dark bar to set the value?

[FPGAzumSpass]

Easiest would be to have a OSD option. Depending on how many different steps are required.

[Peredonov]

That's the approach used in emulators, which works fine, at the risk of giving you too much control. The original idea was to have kids getting some sunlight while playing, and it was actually interesting being forced to plan the right time of day to play to accomplish certain goals in the game, or have an easier time fighting certain enemies. But technically you can always use the brightness steps in an honest way (and just move outside in your imagination)

[seriphinx]

Sort of newish to MiSTer. Love that GBA is in there now. Just wondering if there is a way to rescale the screen, that I might be missing. Even on a 21 inch screen at 3:2 from top to bottom, it seems too blown up to me. Playable for sure. I’d just prefer to shrink it down a bit? Games like Mario Advance aren’t as impacted as games like Need for Speed Underground.

[Sorgelig]

Sort of newish to MiSTer. Love that GBA is in there now. Just wondering if there is a way to rescale the screen, that I might be missing. Even on a 21 inch screen at 3:2 from top to bottom, it seems too blown up to me. Playable for sure. I’d just prefer to shrink it down a bit? Games like Mario Advance aren’t as impacted as games like Need for Speed Underground.

you can add border to the video in MiSTer.ini

[seriphinx]

Sort of newish to MiSTer. Love that GBA is in there now. Just wondering if there is a way to rescale the screen, that I might be missing. Even on a 21 inch screen at 3:2 from top to bottom, it seems too blown up to me. Playable for sure. I’d just prefer to shrink it down a bit? Games like Mario Advance aren’t as impacted as games like Need for Speed Underground.

you can add border to the video in MiSTer.ini

Would I have to make a totally separate ini file so that it doesn’t create this border for every core? Or would I need to edit it on and off each time between GBA and the rest of the cores? Also, does this border reduce the size of the screen? Sorry, I’m very new to this level of tinkering but I’m getting addicted.

[12characters]

Would I have to make a totally separate ini file so that it doesn’t create this border for every core? Or would I need to edit it on and off each time between GBA and the rest of the cores? Also, does this border reduce the size of the screen? Sorry, I’m very new to this level of tinkering but I’m getting addicted.

You can add a core-specific section to MiSTer.ini that overrides the general settings. Example:

Code: Select all

[GBA]
vscale_mode=1 
vscale_border=40

Adjust vscale_border to your liking. The image will be letterboxed to only fit part of the screen.

[Sorgelig]

vscale_mode=1

This is not related to topic.

[trashuncle]

With the new "reverse/rewind" feature, I noticed some audio glitching when playing Donkey Kong Country 2. The rewind feature worked as it should other than the audio occasionally popping or glitching. I will test some other games to see if it happens with other games when the feature is enabled.

[sofakng]

Wow... Rewind + save states + FPGA accuracy? This core is amazing!

I hope similar enhancements could be made to the other 8 and 16-bit cores (NES/SMS/SNES/Genesis).

[trashuncle]

With the rewind capture enabled, definitely noticing occasional hiccups and weirdness with the audio and the gameplay. Its nothing major, but just enough to be noticeable and slightly annoying. I know the feature was just added. I only have 32MB SDRAM and no I/O board, so not sure if that has anything to do with my results testing this core compared to others. I have seen no feedback in the forum other than praise for the new feature.

It could be possible I am the only one experiencing this, but I have tried a handful of games now and the audio and gameplay is for sure affected slightly by the feature and causes performance to change.

[FPGAzumSpass]

There is also a github entry for it, so yes it is known and part of the rewind capture.

The core is halted for ~5ms once a second when creating the savestate for rewind, so this WILL create a (small?) glitch in audio and maybe also video.
Also the gamespeed is reduced by 0.5%, which is probably not noticable.

This can be optimized to ~2ms, which would help a lot, but it's difficult.
a) because the core can use different memories
b) it requires DDR-Ram blockwrites and -reads(blitter)
c) there is no DDR-Ram simulation model available for those blockreads, so every change is try and error with 15 minutes build time.

So my motivation to work on this is really low currently, sorry.

I will probably need the block DDRRam access in future for other projects. When i have that running i may backport it for the rewind feature.
Until then it will stay as is currently, unless somebody writes a configurable blitter for Mister memory.

[trashuncle]

Good to know. It's amazing the feature even exists!

Thanks for the information.

[Ashenshards]

FPGAzumSpass,
I've seen that you have working FPGA cores for playing Gameboy and Gameboy Color games, what are the chances that we might see these cores come to MISTer? Either as stand alone cores, or incorporated into the current GBA core?

[FPGAzumSpass]

While my GBC core can play most GB games and about 80% of the gameboy color games, it's full of flaws, like wrong timing and unhandled edge cases.
I would say, it's roughly in the shape of the GBA core at release time.

So there is no point in releasing it compared to the existing GBC core.

I'm really interested in creating a more accurate GBC core with things like fastforward, savestates, rewind and flickerblend.

But that will not happen this year.
Also i'm not sure if it will fit together with the GBA into the FPGA.
With Mister easy core switch there is little point for doing a combined core.

[spunkworks]

Hi peeps,

Somehow I can't get this core to work on an HP 1280x1024 VGA monitor, I do hear the core's splash sound but the picture remains black after Mister reported input and output resolution.

I have vga_scaler=1 and works for all my other cores, just not the GBA, please help this noob out...

cheers, Vince

[paulbnl]

Set vscale_mode=0 and vscale_border=0 for the GBA core. It is a bug in MiSTer with resolutions narrower than the 3:2 aspect of the GBA.

[spunkworks]

Set vscale_mode=0 and vscale_border=0 for the GBA core. It is a bug in MiSTer with resolutions narrower than the 3:2 aspect of the GBA.

Oh, going to try this, thanks for the reply..

[spunkworks]

Set vscale_mode=0 and vscale_border=0 for the GBA core. It is a bug in MiSTer with resolutions narrower than the 3:2 aspect of the GBA.

Today you are my hero, it worked! thank you

[BitsNStuff]

Just noticed something interesting in the latest build of the GBA core (GBA_20200222), I'm not sure if it;s a bug though or just a change in the way it works.
This is how I've arranged my GBA games on the system...


This is how the display on MiSTer when trying to load a game from within the GBA...


From what I've worked out it's because they have a fullstop/period after the numbers. It's worked perfectly like this up until the latest update and none of the other cores have the same issue. I've also tested it by booting up the GBA core and then using the Load command to browse to games folders for other systems and when they do that those folders have the same issues also.

Just to double check that, I've booted up other cores then used the Load command to browse to the GBA folder and and doing that displays it with the full name as it should.

Interstingly, it seems that the GBA core hides file types when browsing by default so I'm thinking that has probably caused the issue as it seems to be seeing everything after the full stop/period as a file tupe. I don't know if it would be classed as an error or whether it's just a change in the way that cores will be working.

[FPGAzumSpass]

Working here with GBA_20200222 and Main Mister from earlier this year and Foldername "01. Now playing"

Files inside can be seen, too. Only File extensions visible are .gb, .gbc and .gba