30HZ turbo fire bugged?

[psymage]

Expected Behavior

So I'm playing a shmup with a safe spot during a boss fight that requires the player to be in the top middle of the screen holding down 30HZ autofire for a little while in order to chew through the final phase of the fight. I have Turbo enabled, set to 30HZ, and mapped to one button. 30HZ should just be a constant stream of bullets near the top of the screen.

Current Behavior

It seems like the 30HZ goes down to a much slower rate after several seconds and sometimes, it seems to happen sooner. This much slower rate will occur for two to three seconds before resuming with 30HZ. This is in a section of the game where there isn't any frame rate problems either that could cause frames to get dropped. This is a little bit annoying and it doesn't appear in other footage of the game that I could find.

I even tried 29HZ and while it is slightly slower rate obviously, it does not have this issue as the rate of fire stays consistent even when holding it for several seconds at the top of the screen in the same area of the game. I wonder if the 30HZ setting is sometimes trying to do more than 30 presses per second for some reason, but that's my only theory and that could be wrong.

I'm brand new to the GP2040CE firmware as I've only been playing on a fightstick with the RP2040 Advanced Breakout Board for about a month. I got the board off of FocusAttack.

Firmware:

RP2040 Advanced Breakout Board - USB Passthrough (GP2040-CE_0.7.10_RP2040AdvancedBreakoutBoardUSBPassthrough.uf2)
Current: v0.7.10-2-g230983f
Latest: v0.7.10

[tonytoon]

Which game and platform? It is possible the game is not running at exactly 60 frames per second which would make a naïve 30 Hz auto fire out of sync in certain edge cases.

[psymage]

Gun Frontier in MAME, Stage 5 Boss

In that particular section of the stage, it doesn't have a frame rate dip. Here's Jaimers planning that particular section I'm referring to for further context:

https://youtu.be/Ii96536yzWo?si=FH_BnXGAZJpzckMA&t=1209

See his 30HZ turbo fire stays a constant stream until his shot makes contact with something. Mine would drop off to barely any shots for a few seconds for no apparent reason.

Plus, the problem doesn't happen if it's set to 29HZ, which is very similar technically. If the game did have a significant frame rate dip, it would drop off at lower turbo settings as well.

Oh, and I did test this after posting with another game, Metal Black, and had the same issue.

[tonytoon]

Hmm, MAME reports the game as running at exactly 60hz. I'm going to poke at this one as an excuse to better learn the codebase and see if I can determine what's going on. If you use MAME's built in advanced autofire does it have similar issues?

[psymage]

I actually don't use it. I use RetroArch's MAME Current core because I hate standalone MAME's UI so much.