The QS series has 640 separate 'programs', each made up of between one to four samples or sounds, distributed in five banks (128/bank). There are 500 mixes of these programs in five banks (100/bank). Each mix can have between one and sixteen programs. Each 'Q-card' contains 8megs of samples, 128 programs, 100 mixes. All of the QSR, QS6.1, QS7, QS8 have two Q-card slots. So if you want to count only programs then you have 640 + 128 + 128. Now with each Q-card comes a floppy disk that has 256 more programs and 200 more mixes to download into the user banks. You can add a 512sram card @$60 to add another 8 banks of user programs and 8 banks of user mixes. I think at one time I had as many as 2900 different sounds in my QS8. Hope this helps.