09231: 1942: Demo play dies earlier than on PCB

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
09231	Timing	Minor	Always	Aug 2, 2025, 13:36	Aug 2, 2025, 16:52

Tester	hap	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS
Status [?]	Confirmed			Driver	capcom/1942.cpp
Version	0.279	Fixed in Version		Build
		Fixed in Git Commit		Github Pull Request #

Summary	09231: 1942: Demo play dies earlier than on PCB
Description	1942 has 2 demo plays in attract mode. Each of them should die when the large plane is on screen. On MAME the 1st demo one dies a bit earlier. The 2nd demo dies very quickly. Underclock CPU(s) to 98% and demo play will be correct. Suspected to be due to unemulated Z80 WAIT, schematics show WAIT is hooked up (for both Z80). PCB video:
Steps To Reproduce
Additional Information	Initially reported by Guru on shoutbox, I posted it on MT so it won't be forgotten.
Github Commit

Flags
Regression Version
Affected Sets / Systems	1942

Attached Files