05939: prehisle, gensitou, prehislek, prehisleu: Wrong speed

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
05939	Speed	Minor	Always	May 16, 2015, 16:01	Oct 20, 2018, 16:17

Tester	abelardator2	View Status	Public	Platform	MAMEUI
Assigned To		Resolution	Open	OS	Windows Vista/7/8 (64-bit)
Status [?]	Confirmed			Driver	snk/prehisle.cpp
Version	0.161	Fixed in Version		Build	Normal
		Fixed in Git Commit		Github Pull Request #

Summary	05939: prehisle, gensitou, prehislek, prehisleu: Wrong speed
Description	The game runs much slower on the PCB. Wrong speed? Below 60Hz? I have a comparative video. Also I have some photos of the PCB. Video comparative:
Steps To Reproduce
Additional Information
Github Commit

Flags	Verified with Original
Regression Version
Affected Sets / Systems	prehisle, gensitou, prehislek, prehisleu

Attached Files	20150516_163332.jpg (87,539 bytes) May 16, 2015, 16:01 Uploaded by abelardator2
Attached Files	20181019_213818.jpg (28,111 bytes) Oct 19, 2018, 19:43 Uploaded by abelardator2 OSSC Info

No.11669 Mamesick Senior Tester May 17, 2015, 18:30	Confirmed. Looking at other SNK games with very similar hardware, it seems that 59.18~59.16 Hz refresh rate improves it.
No.12624 Mamesick Senior Tester May 6, 2016, 07:31	Isnt this fixed by this commit I submitted a while ago? At least it should be improved. http://git.redump.net/mame/commit/?id=6972e75f6218e8e8a824fc534ac62b03b394930b
No.12684 system11 Senior Tester May 21, 2016, 04:33	Worth noting: the PCB above isn't a normal SNK built one, it's Spanish or Italian and potentially has slightly different oscillators fitted. Also means the one above probably needs dumping in case there's a code difference. Unlikely but possible.
No.12695 abelardator2 Tester May 21, 2016, 16:28	I have a programmer, I can read the code eproms and compare with files dumped in MAME.
No.12696 abelardator2 Tester May 21, 2016, 17:58	I checked my PCB, is the world version.
No.15572 abelardator2 Tester Oct 19, 2018, 19:45	Mi OSSC said 54.03Hz conected on PCB.
No.15591 AJR Developer Oct 20, 2018, 16:17	The 15.61 kHz horizontal rate and 54.03 Hz vertical rate don't seem to be exact divisions of the dot clock (which I believe is correct, though the XTAL appears to be 12 MHz rather than 24 MHz). The screen parameters currently configured give a horizontal rate of 15.625 kHz, which is typical and close enough. 54.03 Hz suggests a vertical line count of about 288, but that doesn't entirely make sense given that Prehistoric Isle uses the same "CLK" video timing gate array as most of the later SNK/Alpha Denshi 68000-based games. (It should be noted that the scanned "Prehistoric Isle" schematics actually describe the hardware of Sky Adventure and Gang Wars.)