Well I don't think the DCS is emulated, I think they changed the music format so they wouldn't have to use DCS. MK1/2/3 look perfect but I think the sound is in a different format.
The games are stored in single files that I don't know how to open up.
MK1 = 137MB
MK2 = 138MB
MK3 = 96MB
I think they emulated the visuals and then changed the format of the music, that's the only way I could explain the large file sizes.
After typing this I checked out the MK2.SR file and this is what I got:
Just as I thought, the music is stored as uncompressed WAVE files, heh. ROM files are also in there. I don't know how to extract this stuff though. Apparently there is a table of contents at the beginning of this file and then a bunch of data after the TOC.
Wonder how they got their MK2IMAGE.ROM, my MAME set is 13MB, heh.
I ripped some music:
I just opened the whole file in Adobe Audition, told it the file was 44.1kHz, 16bit, mono, Intel PCM and it worked fine. The sound effects are 22kHz.
If I could only replace the MK3 music with the music from the CD versions of the games. I'm assuming that Midway made the music in a CD quality stereo format and then converted it to mono and compressed it. The home CD-ROM versions of MK3 have music that sounds EXACTLY like the arcade version except it's stereo 44.1kHz CD quality! I wish Midway would've just put that stereo CD quality music in place of the arcade mono junk since they just used wave files.