Hi,   They are SDcards. Example DPN# would be 1X6VF.   I'm unsure if a normal SD would be sufficient, as there are verified SD cards for Operating Systems to work on. Here a small reference [URL]    
I have recently acquired an R430 without the ISDM module.  I have ordered one (PMR79) to arrive later this week.  There are numerous references in various venues regarding "SD Cards" or "SD Modules" that go in the ISDM module.  What I would like to know is exactly what type(s) of card I need to purchase: 1.  Are the cards SD cards, or miniSD cards, or microSD cards or something else? 2.  Are the cards Dell proprietary or can I purchase them locally? Thank you
R430 ISDM Card