08423: gradius4: "Fatal error: sharc_iop_r: Unimplemented IOP reg 0D at 000224E3" randomly occurs while fighting the 6th level boss

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08423	Crash/Freeze	Critical (emulator)	Random	Sep 27, 2022, 01:37	Dec 2, 2022, 01:05

Tester	Cow	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS	Windows 10/11 (64-bit)
Status [?]	Acknowledged			Driver	konami/hornet.cpp
Version	0.247	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	08423: gradius4: "Fatal error: sharc_iop_r: Unimplemented IOP reg 0D at 000224E3" randomly occurs while fighting the 6th level boss
Description	While fighting the boss of Stage 6, MAME randomly crashes.
Steps To Reproduce	Play the game Fight the 6th level boss ???
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	gradius4

Attached Files	image_2022-09-26_203319164.png (3,431 bytes) Sep 27, 2022, 01:37 Uploaded by Cow
Attached Files	Gradius IV.zip (2,244,406 bytes) Sep 30, 2022, 01:38 Uploaded by Cow SaveState

No.20577 Tafoid Administrator Sep 29, 2022, 00:07	Regular players/Devs might have difficulty getting to Level 6, much less that Boss. Hopefully this isn't too much of an ask but if you do play this game again in the latest release - make a save state before the 6th level boss. Should it Fatal Error during the battle, it will be so much easier for a Dev to be able to zero in on the issue. I've acknowledged for now.
No.20578 Cow Tester Sep 30, 2022, 00:58	That i can do but it will take a will because its Gradius. I didn't even know savestates worked or were stable with Gradius IV
No.20579 Cow Tester Sep 30, 2022, 01:57 edited on: Sep 30, 2022, 19:37	Added SaveState. Lemme know if you encounter any problems
No.20887 riggles Tester Dec 2, 2022, 01:05	Ooh yeah, I remember also getting this back when I tried a playthrough when I was newer to mame. The other issue this game has is the graphics background corruption at stage 3, but other than these 2 things it's so close to being accurate. Happy to see more eyes on this game :)