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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
04301 Sound Minor Always Apr 3, 2011, 12:53 Dec 28, 2011, 09:15
Tester italiandoh View Status Public Platform MAME (Official Binary)
Assigned To mariuszw Resolution Fixed OS Windows XP (32-bit)
Status [?] Resolved Driver
Version 0.137 Fixed in Version 0.144u5 Build I686
Fixed in Git Commit Github Pull Request #
Summary 04301: cobram3: Game plays using Mach 3 sound effects instead of Cobra Command ones.
Description Game plays using Mach 3 sound effects instead of Cobra Command ones.
Steps To Reproduce
Additional Information
Github Commit
Flags
Regression Version
Affected Sets / Systems cobram3
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Notes
5
User avatar
No.07360
Tafoid
Administrator
Apr 3, 2011, 14:42
I think this is correct because it's on hardware which MACH 3 uses... completely different roms and hardware profiles between the two.
User avatar
No.07366
italiandoh
Tester
Apr 3, 2011, 15:43
edited on: Apr 3, 2011, 15:45
No, it is not correct. I have the original arcade machine: http://www.arcade-museum.com/members/member_detail.php?member_id=384678

There are ROM changes on MACH 3 sound board when you convert it to Cobra Command. If Mame is using the sounds from the correct Cobra Command ROM then you have a incorrect dump. If this is the case use the dump on The Dragon's lair Project that I used to convert my machine.
User avatar
No.07372
Fujix
Administrator
Apr 4, 2011, 18:17
italiandoh, could we have audio or video reference of the Cobra Command convert?
I think it is very important for this bug entry.

Thank you.
User avatar
No.07375
italiandoh
Tester
Apr 9, 2011, 19:05
edited on: May 31, 2012, 05:42
OK, here's a video:

User avatar
No.07819
vidpro1
Developer
Oct 6, 2011, 17:44
edited on: Oct 6, 2011, 17:46
Italiandoh is correct. I plugged in the Cobra Command ROMS from the Dragon's Lair project site and made a change to the gottlieb.c driver a while back. Basically the MAME version uses the DAC sounds from MACH 3 ROMS. But the sounds are wrong, the machine guns are the MACH 3's plane explosion. Either the roms are bad or the addressing in the driver is wrong.

On Italiandoh's video you can hear the GI AY-3-8912 Chips firing the machine guns and the the missiles.

From the toying around with the roms and drivers I have it looks like the speech ROM controls how the GI AY-3-8912s work. Also, the conversion kit manual states a modification to the sound board, by adding 2 resistors. See Below.

Modifications are also required to the game hardware
as follows:


SOUND PCB:

Add a 220 ohm resistor across R13
Add a 330 ohm resistor across R14