I've got the Janome 9000 and a ton of memory cards. Yes, this technology is obsolete. You have to remember your machine is probably 10 years old. New machines are released every year. You can still find memory cards second hand or on ebay. You can buy a blank memory card and Scan/Sew to download designs from the net. But keep in mind these older machines have a much smaller embroidery field than the new ones, so finding small designs is key.
Go to the Janome website. All the memory cards are listed and I think which machines they work with.