[RetroArch] Random Button presses in some games

[Vamp898]

Hi there, I have the issue that I have random bottom presses in some games.

In Aladdin (Japanese) for example I have the issue that Aladdin sometimes randomly throws Apples. Not always but especially when i jump. For example in the first level in the first Screen, the first rope you experience that you can climb up, if I jump left from the rope, he throws Apples while jumping.

In Sonic on the GameGear I have the issue that one button jumps perfectly, the other button (I think 1) randomly presses pause when jumping.

This happens in the Smartphone and on the PC with different controllers. I do not have this issue with any other emulator like Genesis Plus GX, it only happens with PicoDrive

I tried resetting all settings but there is no difference

Maybe unrelated but when overclocking the CPU and then play Afterburner II, all missiles get shot constantly until the ammo is gone, no matter if I press an button it not. But that issue is gone when disabling the overclocking

When overclocking the CPU in Genesis GX, no missiles are getting shot, no matter if 400% or even 500%

The issue with Afterburner even happens when no controller is plugged in at all.

[irixxxx]

Which version of RA and PD have you used?

[Vamp898]

1.21.0 - PicoDrive (2.05-975cdaf)

[irixxxx]

I've tried to reproduce this for quite some time now, but I haven't had any luck with it. Please try finding a case were this is happening almost always so that I have a chance to see where it comes from.

As well, please check with older versions if this is happening there too, and if you have the ability to bisect this for me it would help a lot.

[Vamp898]

This only happens in combination with RetroArch. I am trying to find out why but no matter what combination of controller and configs and settings i try, nothing seems to have effect on this.

I even tried disabling controller remapping for this core but no effect. I will report it at RetroArch and see what they have to say

The easiest way to reproduce for me is: Afterburner II with 400% Clock Speed --> Constantly shoots missiles.

In PicoDrive, that doesn't happen --> Everything is fine (no issues in other games too)

With RetroArch it does happen.

[irixxxx]

I don't see it with RA 1.7 and PicoDrive 2.05 under linux on aarch64. Maybe our configurations differ. Please send me your retroarch.cfg, retroarch-core-options.cfg, and the Picodrive.opt file.

[notaz]

FWIW the Afterburner II missile issue reproduces here too, but nothing strange there as games may misbehave due to messed up timing (it doesn't matter much if it doesn't happen in Genplus as it probably implements the overclock differently).

@Vamp898 do you use savestates? I've seen inputs misbehave before after loading old savestates, even on standalone, but assumed it's just savestate version incompatibility.

[irixxxx]

Just tried, it also reproduces on standalone here.
And I just noted I still have run-ahead enabled. I'll turn it off and check if I can reproduce one of the other reported problems.

[Vamp898]

configs.tar.gz

Here are my configs. I did not include the config from the Stand Alone PicoDrive as this is the blanko config that was created when starting PicoDrive for the first time (The only thing i changed was the Clock Speed)

I tried building PicoDrive as an libretro core for the sake of it, but that did not change anything.

But i made a video. On the left you see RetroArch with the self compiled libretro core and on the right the PicoDrive compiled using the exact same sources

https://youtu.be/2Mab3I_i2jo

[irixxxx]

@notaz are you able to reproduce this, apart from that After Burner case?
@Vamp898 as you mention clock speed, do you see these problems with overclocking off?

Overclocking wouldn't explain the GG case, as the Z80 can't be overclocked ATM.

[Vamp898]

@irixxxx Not in afterburner, but the other Issues like Aladdin randomly throwing apples and stuff like that do still exist. But they are harder to trigger. The Afterburner one is by far the easiest to reproduce

@notaz I did not use any savestates so far

[notaz]

I've tried it again (RA on x86 pc) and was able to reproduce it both overclocked Afterburner (100%) and Aladdin (Japan) (occasionally). I've even partially debugged it: it's caused by the padTHLatency thing. If I add this:

diff --git a/pico/memory.c b/pico/memory.c
index b53cc256..b6c8f01b 100644
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -525,6 +525,8 @@ static NOINLINE u32 port_read(int i)
   // Decap Attack reportedly doesn't work on Nomad but works on most
   // other MD revisions (different pull-up strength?).
   u32 mask = 0x3f;
+if ((int)(cycles - padTHLatency[i]) < 0)
+ printf("%d (%u - %u)\n", cycles - padTHLatency[i], cycles, padTHLatency[i]);
   if (CYCLES_GE(cycles, padTHLatency[i])) {
     mask |= 0x40;
     padTHLatency[i] = cycles;

With this playing Aladdin (Japan) occasionally prints:

-264 (327517967 - 327518231)
-332 (344156079 - 344156411)
-332 (363354145 - 363354477)

and Aladdin will throw an apple. What's worse, after a while of playing the music seems to break.

I don't think padTHLatency is ever supposed to go ahead of the cycle counter by more than 25, is it?

[notaz]

Nevermind I forgot the overclock was still on after the Afterburner test. Still it's not great to have an overclock option that breaks all the CYCLES_GE checks. At the very minimum you should add something like:

if (PicoIn.overclockM68k) {
      struct retro_message_ext msg = {
         "Overclock is on, everything is now broken",
         2000,
         3,
         RETRO_LOG_WARN,
         RETRO_MESSAGE_TARGET_ALL,
         RETRO_MESSAGE_TYPE_NOTIFICATION,
         -1
      };
      environ_cb(RETRO_ENVIRONMENT_SET_MESSAGE_EXT, &msg);
}

at the end of retro_load_game() so that the user doesn't forget.

[Vamp898]

If that maybe helps, another Game i have issues with is Sonic (1) on the GameGear. The B Button Jumps perfectly but the A Button randomly presses pause (or the other way around, i am not 100% sure about the mapping on the GameGear). But one of these two buttons randomly causes to pause the game.

This only happens when i keep the button pressed, so for longer jumps

[irixxxx]

Having reviewed how this overclocking is implemented, I'd say this should be disabled for now. This rewinding the clock cycle count has the potential of breaking other things as well. @notaz your opinion?

[irixxxx]

@Vamp898 If you say randomly, what does this mean? 1 in 10? 50? 100?
I'm currently focusing on Aladdin. Which country version are you using? Could you provide a video for that as well, so that I can see what exactly you are doing?