HELP with a mpc 2000

i recently got a mpc 2000 and im trying to lay down some drums that will come off one floppy. but i like the snares and high hats on another floppy and when i load the other floppy in the old rythm i laid down doesnt stay, the new floppy sounds take over the old drum line.

so how would i be able to lay down multiple tracks with different floppies with different sounds.

dont own a mpc 2000 but try uploading them to a differen program?

like make a new program.

if it works then good if it doesnt then another good lad will help out