08183: nespal [gimmick]: DPCM audio plays at wrong pitch

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08183	Sound	Major	Always	Jan 17, 2022, 03:01	Sep 29, 2022, 19:16

Tester	kmg	View Status	Public	Platform	MAME (Self-compiled)
Assigned To	kmg	Resolution	Fixed	OS	MacOS X
Status [?]	Resolved			Driver	nintendo/nes.cpp
Version	0.239	Fixed in Version	0.240	Build	64-bit
		Fixed in Git Commit	412098b	Github Pull Request #	#9167

Summary	08183: nespal [gimmick]: DPCM audio plays at wrong pitch
Description	The bass line in the title screen music (and other tracks) is done by playing samples on the NES's DPCM channel. It is noticeably out of tune (about a half-step flat?) with the melody and implied harmony. Is this an APU bug that affects all PAL games? Presumably it is correct on hardware. Other emulators have correct pitch.
Steps To Reproduce	mame nespal gimmick or alternately mame famicom gimmickj to hear the music in tune (also has additional sound channels)
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	nespal [gimmick]

Attached Files

No.19695 kmg Senior Tester Jan 17, 2022, 07:28 edited on: Jan 17, 2022, 08:39	Alright, it looks like this is due to not having an appropriate table to generate the correct frequencies for the DPCM channel on PAL—it just reuses the NTSC table. With a correct table I think the PAL version of Mr. Gimmick should have music at approximately the same pitch as the NTSC version. In other words it should sound very close to running "mame famicom gimmickj" and then turning the volume off on that game's extra AY clone chip.
No.19696 kmg Senior Tester Jan 17, 2022, 10:05	There are probably other examples, but it turns out Sunsoft really likes this bass line via DPCM samples idea. Besides "gimmick", sets "batmanrj", "gremlin2", "silius", "sspyhunt", and "ufouria" are all PAL versions and all sound horrible due to the bass part being flat on the nespal driver.
No.19708 kmg Senior Tester Jan 22, 2022, 21:28	I've added the commit this was fixed in. I believe this can be closed unless someone knows a reason otherwise.