[my58vw]

I have no idea what red said above

Any beatmania that is a key disc can boot any append, meaning gottamix 2 and club mix (the last two appends in the beatmania series), can be loaded by beatmania, the first key disc. Likewise, the last master discs (6th mix + core remix) can launch any early append.

The only 2 disc beatmania game was "beatmania", which comes with beatmania 2nd mix and Yasriu mix (however it is spelled). Yasriu was an append, beatmania 2nd was a key disc.

As for what will work for beatmania, a japan ps2 or psx work equally well for appends - I have both and they work well. I also have a chipped psx and it loads psx appends fine (with master disc and codes). I would recommend a real japan psx or ps2 if you want to run these games. BTW 5-key beatmanias are some of the best in the entire beatmania series, if you can deal with the later 90's graphics...