07819: megadriv [quacksht]: Corrupted sound when restoring save states

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
07819	Save/Restore	Minor	Random	Dec 12, 2020, 01:23	Jul 5, 2021, 19:58

Tester	StHiryu	View Status	Public	Platform	MAME (Unofficial Binary)
Assigned To		Resolution	Open	OS	Windows Vista/7/8 (64-bit)
Status [?]	Confirmed			Driver	sega/mdconsole.cpp
Version	0.226	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	07819: megadriv [quacksht]: Corrupted sound when restoring save states
Description	Although save states seem to be supported for this system, sometimes when a state is restored the sound is affected in several ways: Sometimes the sound disappears or noise is generated, or the soundtrack is distorted for a couple of seconds. It's a behavior similar to some system16 games such as Golden Axe, which in previous versions lacked support to save states if I remember well. As a curiosity, once the state is loaded if a sound effect is played strong enough, if we load the state again the melody sounds correctly. In this report I attach a save state from Quackshot, in which you can see a constant beep for approximately 2 seconds
Steps To Reproduce	1-Load the save state provided using Megadrive (Europe,PAL) 2-Wait until Donald picks some sacks of money and load state again 3-Notice the melody changes the first 2 seconds of gameplay
Additional Information	-Provided save state 'w' -The rom for Quackshot is from No-Intro set: QuackShot Starring Donald Duck ~ QuackShot - I Love Donald Duck - Guruzia Ou no Hihou (World) (v1.1).7z
Github Commit

Flags
Regression Version
Affected Sets / Systems	megadriv [quacksht]

Attached Files	w.zip (40,401 bytes) Dec 12, 2020, 01:23 Uploaded by StHiryu Save state

No.18271 StHiryu Tester Dec 17, 2020, 00:11	Keep in mind this bug affects the megadrive system. I put Quackshot as an example only but happens in many others like Strider, Golden Axe or Ghoul'n Ghost.
No.18272 Tafoid Administrator Dec 17, 2020, 00:16	I understand. Many years back when I tested wavdata for many soundchips, none of them I can remember worked 100% the same between normal timed run and a staggered -autosave run. I just kept to a set that can be reproduced (from softlist) as such romsets are easier to find. The sound cores need work to account for ALL items emulation expects. Often, when improvements are made to any core or even a driver, the save states are often the last thing to be considered.

No.18271

StHiryu

Tester

Dec 17, 2020, 00:11

Keep in mind this bug affects the megadrive system. I put Quackshot as an example only but happens in many others like Strider, Golden Axe or Ghoul'n Ghost.

No.18272

Tafoid

Administrator

Dec 17, 2020, 00:16

I understand.

Many years back when I tested wavdata for many soundchips, none of them I can remember worked 100% the same between normal timed run and a staggered -autosave run. I just kept to a set that can be reproduced (from softlist) as such romsets are easier to find.

The sound cores need work to account for ALL items emulation expects. Often, when improvements are made to any core or even a driver, the save states are often the last thing to be considered.