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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
08446 Misc. Major Always Oct 18, 2022, 19:41 Oct 20, 2022, 11:22
Tester Firewave View Status Public Platform MAME (Official Binary)
Assigned To kmg Resolution Fixed OS Windows 10/11 (64-bit)
Status [?] Resolved Driver
Version 0.248 Fixed in Version 0.249 Build 64-bit
Fixed in Git Commit 05b04a4 Github Pull Request # #10451
Summary 08446: famicom [famijmp2]: Does not start (grey screen)
Description The sets does not start and only shows a grey screen.
Steps To Reproduce
Additional Information
Github Commit
Regression Version
Affected Sets / Systems famicom [famijmp2]
Attached Files
png file icon 0003.png (4,160 bytes) Oct 20, 2022, 02:10 Uploaded by Foxhack
Screenshot from MAME 0.248 running the game
There are no relationship linked to this issue.
User avatar
Oct 20, 2022, 02:08
It -does- kinda work.

If you load the game the first time, you only get a gray screen. But if you press F3 (to reset), the game boots.

It looks like the game doesn't start at first because it's missing its battery backed NVRam data. So if you load the game and it doesn't find anything, it just hangs. Once you reset, press Shift+F3 to force a power cycle, or close MAME and restart it, the game will boot normally since an NVRam file is created during any of those three situations.
User avatar
Senior Tester
Oct 20, 2022, 04:04
This one is a relative of the other Bandai games but without the EEPROM. I wonder why it needs reset? Somehow related to IRQ? It does look like the parent class function that writes the IRQ regs is overridden and so it has no working IRQ. That probably explains the broken effect on the title screen at least.
User avatar
Oct 20, 2022, 04:16
edited on: Oct 20, 2022, 04:19
I don't think that has anything to do with it, since resetting creates the battery backed memory that it's supposed to have. If it finds it empty, it probably assumes the backup battery is dead, and it won't boot. But since mame generates empty save data after running the game once, it works after you try it again.

I tested this out by shutting off mame, deleting the memory, and starting the game again. Gray screen. Closed mame, loaded the game again, it works since there's a battery backup file now.
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Senior Tester
Oct 20, 2022, 06:56
edited on: Oct 20, 2022, 06:56
It seems this is a know problem:
There are several games that need this or that RAM to be not zero filled to run. Bad programming that depends on random uninitialized RAM contents.