MegaCD core goes straight to CD player after ~10 seconds with no game loaded

[adimifus]

I originally posted this issue here:
MiSTer-devel/MegaCD_MiSTer#110
But it seems like it may be an issue with the MiSTer binary instead.

The MegaCD core will automatically go to the CD player after ~10 seconds when using US or EU model 1 BIOS. This does not happen with JP model 1 or any model 2 BIOS.

I found out through testing of different combinations of MiSTer binaries and MegaCD core revisions that the latest combination that DOESN'T interrupt the boot animation is:
MiSTer_20230526.bin + MegaCD_20230224.rbf

With MiSTer_20230703.bin, the animation is interrupted on MegaCD_20230224.rbf as described above.

Starting with MiSTer_20230716.bin, MegaCD_20230224.rbf no longer boots properly (sits at boot animation screen with only static background and doesn't respond to input)

I tested with US v1.00, US v1.10, US V1.10 region patched, EU v1.00 and EU v1.00 region patched.

MegaCD_20230716.rbf and newer don't work with MiSTer_20230526.bin. It will only boot to a static background image with no animation and no response to input. Additionally, with MiSTer_20230526.bin all revisions of MegaCD earlier than 20230224 also work properly.

Because the behavior of the 20230224 revision of the MegaCD core changes depending on the MiSTer binary, I believe this issue may be caused by the MiSTer binary rather than the MegaCD core.

[MP2E]

Looks like it happened at commit 53f1ca1

[birdybro]

MiSTer-devel/MegaCD_MiSTer@667ff62 - correlating update to the core here. Still could potentially be related to the core, but could be related to the Main binary.