Viewing Issue Advanced Details
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
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
jpg file icon 20150516_163332.jpg (87,539 bytes) May 16, 2015, 16:01 Uploaded by abelardator2
abelardator2
jpg file icon 20181019_213818.jpg (28,111 bytes) Oct 19, 2018, 19:43 Uploaded by abelardator2
OSSC Info
abelardator2
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Notes
7
User avatar
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.
User avatar
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
User avatar
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.
User avatar
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.
User avatar
No.12696
abelardator2
Tester
May 21, 2016, 17:58
I checked my PCB, is the world version.
User avatar
No.15572
abelardator2
Tester
Oct 19, 2018, 19:45
Mi OSSC said 54.03Hz conected on PCB.
User avatar
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.)