00941: tp84: The startup 'tune' no longer sounds like the original game after the fixes to the SN76496 sound core.

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
00941	Sound	Minor	Always	Feb 7, 2008, 10:35	Nov 16, 2009, 15:21

Tester	Sune_S	View Status	Public	Platform	MAME (Official Binary)
Assigned To	Lord Nightmare	Resolution	Fixed	OS
Status [?]	Resolved			Driver	konami/tp84.cpp
Version	0.96u3	Fixed in Version	0.135u1	Build
		Fixed in Git Commit		Github Pull Request #

Summary	00941: tp84: The startup 'tune' no longer sounds like the original game after the fixes to the SN76496 sound core.
Description	I noticed the startup 'tune' in Time Pilot '84 no longer sounds like the original game after the recent fixes to the SN76496 sound core. It's difficult to describe it in words. The attached MP3 plays a recording from my PCB, then a recording from Mame 0.96u3.
Steps To Reproduce
Additional Information
Github Commit

Flags	Verified with Original
Regression Version
Affected Sets / Systems	tp84

Attached Files	SN76496096u3gre.mp3 (388,284 bytes) Feb 14, 2008, 17:41
Attached Files	TP84sound.jpg (1,078,408 bytes) May 16, 2008, 17:02

No.00609 nicolasa Developer Apr 7, 2008, 15:15	Could you please check if your PCB has SN76489 or SN76489A on it?
No.00610 Kold666 Developer Apr 7, 2008, 17:03	on my pcb they have erased chip markings unfortunately. if it can be of any help, on other pcbs of the same era, they use A revisions
No.00795 Sune_S Senior Tester Apr 24, 2008, 17:13 edited on: Apr 25, 2008, 15:44	What's the location of the chip? I've looked all over and I can't find it. I found just one IC with the markings scratched off, but that only has 14 pins. Maybe this board uses a clone of the SN76489 with another name?
No.00821 nicolasa Developer Apr 26, 2008, 15:10	There should be three 76489 @ 5E, 6E and 7E, plus an empty space for a fourth one @ 4E.
No.00988 Sune_S Senior Tester May 16, 2008, 17:11	I've uploaded a photo of the ICs in that location. All three are labeled J319A Y2404, and carry the TI logo.
No.00999 Lord Nightmare Developer May 18, 2008, 05:49 edited on: May 18, 2008, 05:52	Hmm... Try replacing the three lines (near line 453) which are: MDRV_SOUND_ADD(SN76489A, XTAL_14_31818MHz/8) /* verified on pcb / with MDRV_SOUND_ADD(SN76489, XTAL_14_31818MHz/8) / verified on pcb */ and see if it sounds any better. If it does (and I suspect It will) I have a theory about why the chips are marked so strangely on that PCB: Konami probably designed the game to use the SN76489, but when the time came around to fabricate the PCBs, TI had long since stopped production of that chip in favor of the SN76489A (which is slightly different sounding). So, Konami probably commissioned TI to make a new batch of SN76489s, which were custom marked. If it still doesn't sound right even with those fixes, I don't really know what's going on. More tests (possibly tests on your pcb) may be necessary.
No.01000 Machone Tester May 18, 2008, 13:07 edited on: May 18, 2008, 13:07	Doesn't seem to make a difference. Perhaps this is related to Mikie bug 00754 , which also sounded worse after the fixes to the SN76496 core.
No.01006 Sune_S Senior Tester May 18, 2008, 21:48	@LM I'll be happy to do whatever is required as long as I feel confident I can do it without killing the PCB. I'm not scared of soldering, I've done some basic repairs and component replacement before without blowing up anything. I have a basic digital multimeter and soldering equipment, but currently nowhere to hook up PCBs....I guess I could throw something together though. Let me know.
No.01008 nicolasa Developer May 19, 2008, 12:38	Changing from SN76489A to SN76489 definitely DOES make a difference so I don't know why you wouldn't be hearing it. Did you change all three instances? Regarding the testing, the easy thing to do would be replace the three chips with proper SN76489 and SN76489A, if you can find them on other pcbs.
No.01073 Sune_S Senior Tester May 24, 2008, 04:47	Unfortunately none of my other PCBs (or other toys) have this chip. I'll see what I can do. If I somehow manage to source three SN76489s and solder them in, then what?
No.01075 nicolasa Developer May 24, 2008, 09:29	Please make a recording of the sound before and after replacing the chips so we can compare what's different.
No.05169 Tafoid Administrator Nov 16, 2009, 15:21	With the work that Lord Nightmare has been doing with SN sound chips - this one looks like it will be resolved for u1.