LPChip, of course you can access XG instruments. However, as the name implies, XG is an extended version of the MIDI standard, and thus some things will work differently. I don't know the commands by heart, but you can f.e. use SendSX to capture program changes that the synth sends to your PC when connected via MIDI, and then use those messages to change the patches on the synth again. That said, weren't the standard XG instruments reachable by selecting the proper bank? I.e. all the General MIDI patches are in bank #0, and the XG patches are on the higher bank? That's how I remember it being organised on my CS1x again. Or are you talking about patches that are only reachable through a special play "mode" on the synth, like the "Performance" voices on the CS1x?