good news for you. i just bought a card last week so i've just researched exactly what you need.
there is a great link that you can get to by going to
http://www.alesis.com to support to support links to support links to
quadrasynth site. just start searching around like crazy and you will find what you need plus some extras.
to answer your question quickly. SRAM cards are best for storing banks (like mixes and programs) with the 512 card you can store 8 complete banks and access/store them just as easy as having 8 extra user banks. you can also store samples on the SRAM cards but it's not really practical since an 8MB SRAM costs $300 or $400. the 512 is only about $75 from pretech (i just got one).
the flash cards are better for samples like .wav samples and such. i don't have much experience with this yet. flash cards can also save one and only one extra bank.
do you have soundbridge and freeloader? if not get it now from the sites i referred you to. set up the serial driver. technically you don't need a card since with this you could always save a restore any number of user presets or banks but i guess that not very convienient if you have to keep loading and swapping banks. does this make any sense? sorry if if doesn't...have to go to class now.
questions, let me know.
jeff
