UniBIOS 4.0 splash screen behaves erratically, depending on unexpected factors

[c0d3h4x0r]

This might be a bug with the UniBIOS rather than this core, but I can't tell which.

Apparently there are two dumps of the sfix BIOS ROM floating around:

1. sfix.sfx - bad dump used by MAME 0.127 and earlier (md5: eba274d931f630efbbf723c19fcd8744)
2. sfix.sfix (notice the differently-spelled extension) - redump used by MAME 0.128 and later (md5: aa2b5d0eae4158ffc0d7d63481c7830b)

When using dump #1 renamed to sfix.sfix with the latest MiSTer NeoGeo core and UniBIOS 4.0, the UniBIOS appears to work correctly: after loading the core and a game ROM, when the UniBIOS splash screen shows, the user can press ABC buttons simultaneously to enter the UniBIOS settings page.

But when using dump #2 (which is the one pulled down by the BIOS updater script), the UniBIOS behaves erratically: after loading the core and a game ROM, pressing ABC buttons simultaneously during the UniBIOS splash screen does not enter the UniBIOS settings page. To get it to work, the user must press SELECT+START after the game boots to get into the UniBIOS in-game menu, then choose to soft reset... and then on the subsequent restart, pressing ABC on the UniBIOS splash screen finally works. This workaround sticks until the core is unloaded or the system is reset. The next time the core is loaded, the same workaround must be performed again.

[c0d3h4x0r]

More strange findings:

• If I use the good dump (#1) with any earlier UniBIOS version, the UniBIOS splash screen doesn't show up at all.
• If I use the good dump (#1) with UniBIOS 4.0, the UniBIOS splash screen appears, but:
  • If I use the default core setting Input: Joystick or Spinner, then pressing ABC buttons at the UniBIOS splash screen does nothing.
  • If I change the core setting to Input: Joystick (no spinner), then pressing ABC buttons at the UniBIOS splash screen works as expected.

Note: My only input devices are a Bluetooth 8bitdo M30 gamepad, a Bluetooth keyboard, and a non-Bluetooth wireless USB mouse. All of my above repros were performed with the gamepad and keyboard paired and turned on, and with the wireless mouse turned off (but its USB dongle still plugged into MiSTer). I do not have any actual "spinner" input device.

[sorgelig]

Because of how spinner on NeoGeo works it may hold several buttons/directions in some positions even actual spinner isn't connected. So better to keep spinner option disabled by default.

[synrais]

I found that if you set the service dip on, load into service then exit, turn dip off, you can now A+B+C to enter the splash.

[sorgelig]

Should be UniBIOS issue