Dataeast Vapor Trail pcb question

[dink]

I have a question to anyone who has played the arcade pcb version of Vaportrail - does the music speed up when you mash the fire button and slow down when your ship stops fireing like it does in emulation? (MAME/FBA, etc)

thanks and best regards,
- dink

[system11]

I have a question to anyone who has played the arcade pcb version of Vaportrail - does the music speed up when you mash the fire button and slow down when your ship stops fireing like it does in emulation? (MAME/FBA, etc)

thanks and best regards,
- dink

I had a spare PCB I needed to drag out and test/sell - so this prompted me to actually do so.

Yes it's a MAME bug, actually it was reported years ago too:

http://mametesters.org/view.php?id=2108

[dink]

Thanks! I'm working on the emulation in fbalpha(dotcom), and we have the same exact bug, but totally different code. weird, eh? I plan on digging pretty deep on this one, and when a fix is found, the info will be made available to the MAME guys, of course!

best regards,
- dink (fba dev-hippie)

[dink]

Problem solved!
The huc6280 (audiocpu) is running too fast - 8055000hz is totally wrong, there must be some sort of divider that wasn't accounted for.
Setting the huc to 2685000hz, the bgm plays perfectly.
In Rohga(.c aka the sequel), the huc is running at 32220000/4/3
vaportra.c, its running at 32220000/4 - missing the /3 divider

best regards,
- dink