08565: ddragon and ddragon2 clones: mamedev had done overclocking changes to avoid gameplay slowdown and delay in input buttons , but not was enough

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08565	Gameplay	Minor	Always	Feb 18, 2023, 07:56	Apr 8, 2023, 21:48

Tester	Augusto	View Status	Public	Platform	SDLMAME
Assigned To		Resolution	Open	OS	Linux (64-bit)
Status [?]	Direction Needed			Driver	technos/ddragon.cpp
Version	0.251	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	08565: ddragon and ddragon2 clones: mamedev had done overclocking changes to avoid gameplay slowdown and delay in input buttons , but not was enough
Description	Hello. OSD cpu overclocking are for debugging and not for gameplay. Please not post wrong post about issues in gameplay using cpu overcloking. Doing it can break the game code internal logic. I only use OSD CPU overclocking values for debugging , but have two exceptions being Double Dragon 1 and 2. I don't know other games that need overclocking. When ddragon1 and 2 were added in MAME the emulation was much more slow than the arcade. In both ddragon and ddragon2 was done changes in MAME previous versions being : 0.122u7 CPU HD6309 clock was changed to 12 MHZ being an overclock to avoid slowdowns in gameplay. 0.196 CPU HD6309 was changed to HD6309E 3 MHZ That means ddragon dev had done changes for avoid the extreme slowdowns because the game was almost unplayable. After of the changes above both ddragon 1 and 2 emulation have good speed, but is as if was tested only in stage 1 because have several areas in the game with much slowdowns mainly when more than 4 sprites are on screen at same time having much delay in inputs buttons doing an unexpected gameplay. The images are some areas with slowdowns. Please load the save states for both ddragon and ddragon2j and use the values below after loaded each save state. In ddragon cpu0 in 140 % and cpu1 in 140 % not happen slowdowns. In ddragon2j cpu0 in 120 % and cpu1 in 140 % not happen slowdowns, but will happen slowdowns in few moments. Run smooth if using cpu0 140 % and cpu1 140 %. I have tested both ddragon and ddragon2j from begin to last stage using the cpu overclocking values above and not happen any problems or bugs. Thanks for reading. Have an nice day.
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	ddragon and ddragon2 clones

Attached Files	ddragon-1.png (14,545 bytes) Feb 18, 2023, 07:56 Uploaded by Augusto
	ddragon-2.png (19,709 bytes) Feb 18, 2023, 07:56 Uploaded by Augusto
	ddragon2j-1.png (11,236 bytes) Feb 18, 2023, 07:57 Uploaded by Augusto
	ddragon2j-2.png (12,575 bytes) Feb 18, 2023, 07:57 Uploaded by Augusto
	ddragon2j-3.png (14,579 bytes) Feb 18, 2023, 07:57 Uploaded by Augusto
	ddragon2j-4.png (13,803 bytes) Feb 18, 2023, 07:58 Uploaded by Augusto
	sta.7z (33,037 bytes) Feb 18, 2023, 07:58 Uploaded by Augusto

No.21086 hap Developer Feb 18, 2023, 14:39	Yes, it has slowdowns on the arcade cabinet. See last comments here claiming it's pretty accurate: https://mametesters.org/view.php?id=2106 Or did it slow down more since mid-2013?
No.21087 Augusto Tester Feb 18, 2023, 23:44 edited on: Feb 18, 2023, 23:47	All good with you ? Here in Brazil had both original and bootlegs PCBs of Double Dragon. I only had played Double Dragon 2 PCB bootleg version not dumped in MAME project. I can confirm without any doubts when both Double Dragon 1 and 2 were added in MAME ( before version 0.36) comparing the emulation was much more slow than the arcade. ddragon driver dev had interest in avoid slowdowns problems. Thus was done changes in cpu and clock values. After both ddragon 1 and 2 had good emulation speed. However in both games in some areas happen much slowdowns not being an bug related with the link https://mametesters.org/view.php?id=2106 If you load both games using the saves states in that report will see much slowdowns. I remember playing in arcade even in original PCB not had delay in input buttons. Only slowdowns when moving sprites. I not understand if devs have any interest in optimize cpu clock values avoiding slowdowns or leaving the slowdowns in same speed as the arcade thus I had created that post showing the slowdowns. Using the tested cpu overclocking values in both ddragon 1 and 2 not does bugs or others problems. The gameplay speed will be in good speed. I only see 2 choices : - use current cpu values for gameplay speed to be same speed as the arcade even having slowdowns. - change cpu clock values for both cpu0 and cpu1 avoiding slowdowns and allowing an normal gameplay speed. I understand that MAME priority not is change the source code for better gameplay being an correct choice , but sincerely playing both ddragon 1 and 2 with current cpu clock values is an unexpected gameplay experience. The user will try change the cpu clock values and both ddragon 1 and 2 not does any bugs overcloking thus for luck avoiding here posting wrong bug issues.
No.21093 ICEknight Tester Feb 23, 2023, 16:11	The goal of MAME is to mimic the original hardware, not to improve it.
No.21126 Augusto Tester Feb 28, 2023, 02:16	"The goal of MAME is to mimic the original hardware, not to improve it." Yes. However MAME current version ddragon 1 and 2 use cpu overclock above original arcade being both exception about that rule. That was decision of ddragon.c driver coder because the game was absurdly slow. Thus being I only had created that post to suggest change cpus to an more high value because ddragon1-2 are using cpu overcloking above of the arcade. I don't know an emulated arcade more slow than ddragon1-2.
No.21127 ICEknight Tester Feb 28, 2023, 18:28	In that case, I think the issue to report would be that they don't run as slow as they should...
No.21128 Osso Moderator Feb 28, 2023, 19:08	After a quick glance in the driver I can't see the overclock. Augusto, can you point it out to me?
No.21131 Augusto Tester Mar 1, 2023, 03:03	I not remember exactly what was the HD6309 clock when ddragon was added in MAME before version 0.36. Possibly was less than 6 MHZ. In MAME version 0.122u7 CPU HD6309 clock was changed to 12 MHZ (much more high than PCB cpu frequency). Obviously that action was done to avoid slowdown and allow an normal gameplay speed. After in version 0.196 CPU HD6309 was changed to HD6309E 3 MHZ (3Mhz internally multiplied by 4 = 12 Mhz).
No.21298 Alex7 Tester Apr 8, 2023, 21:48	Original hardware seems to be the usa version &ab_channel=ArtemioUrbina