Double Dragon II beta

Here comes Double Dragon 2!

I have added the files to the Double Dragon 1 beta folder. Get the link from the original post. 

This game is similar to the first one hardware wise but it is not the same board. The designers replaced the MCU device with a regular Z80 (while keeping the bus arbitration virtually unchanged). Then they replaced the two individual OKI MSM5205 chips by a single OKI MSM6295, which is quite an improvement over an MSM5205. This change freed a lot of space on the board. The sound CPU also changed from a M6809 to a Z80. So although the spirit is the same, it is a different, non-compatible board. Only the video circuit remained practically intact.

All the sound effects are produced by the MSM6295 chip. MAME seems not to filter it all and that doesn't seem right. I have included attached to this post a recording from a Double Dragon 2 PCB so you can hear the music/FX balance and FX treble. I must say the recording is from what I think is a bootleg PCB. About ADPCM, this is a new IP and I am still working on it so expect some glitches.

Also, I know Double Dragon is still giving sync problems to some users. I think part of this is that the video runs at 57Hz and not all screens will take that value. This is the same for Double Dragon 2. I am considering options and also looking at other possible causes.

There is one more game, called China Gate, which uses the same video hardware. I hear it was popular in Italy and Korea. I am considering doing it too as the last core in this Technos series. Although if you find a Technos game in MAME with equal screen resolution, refresh rate and scroll planes, let me know. There is a chance it shares video hardware even if MAME uses a different driver for it.

Bruno Silva prepared the MRA files for this too. Thanks again, Bruno!

Enjoy the beta and thank you :-)