06552: alpiltdx, hotd2, hotd2o, airlbios, possibly others: Machines using earlier BIOS/custom BIOS version black screen

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
06552	Gameplay	Critical (emulation)	Always	Apr 27, 2017, 03:42	Aug 20, 2019, 10:42

Tester	Tafoid	View Status	Public	Platform	MAME (Official Binary)
Assigned To	MetalliC	Resolution	Fixed	OS	Windows Vista/7/8 (64-bit)
Status [?]	Resolved			Driver	sega/naomi.cpp
Version	0.185	Fixed in Version	0.188	Build
		Fixed in Git Commit		Github Pull Request #

Summary	06552: alpiltdx, hotd2, hotd2o, airlbios, possibly others: Machines using earlier BIOS/custom BIOS version black screen
Description	Games that used to boot, notably, House of The Dead 2, no longer boot and show black screen
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version	0.184
Affected Sets / Systems	alpiltdx, hotd2, hotd2o, airlbios, possibly others

Attached Files

No.13951 Osso Moderator Jun 29, 2017, 14:06	Reverting this seems to "fix" it: https://github.com/mamedev/mame/commit/c65634ec7208bd3bdecc3fd138270af40df3fd64 Maybe the special bioses are more sensible regarding MIE clock?
No.13962 MetalliC Developer Jul 6, 2017, 10:29 edited on: Jul 6, 2017, 10:36	later research shows this MCU uses some "fast Z80" core, possible something like Kawasaki KC80 or ASCII R800. measured execution rate of NOP instructions in RAM is about 3.19M per second, which gives even less frequency number then converted to "regular Z80" clock - 12.76, however other instruction runs faster than regular Z80 at such clock, so it looks like this CPU core have much different opcode/cycles table. I'll add more comments about current research results and probably revert mentioned frequency change during this 0.188 dev cycle.
No.16774 MetalGod Senior Tester Aug 20, 2019, 10:42	Indeed, It was fixed in mame 0.188.