I understand that a SIM card has memory, and that some or maybe all of them also include microprocessors.  They act as peripherals that are more than just flash memory.I would like to be able to read the contents and extract my contacts and messages, for backup, so I bought an el-cheapo SIM Card Reader that plugs into a USB port.  But when I plug it in it is as if it isn't even there.  So how can I get access to the data?Secondly, I understand that they can affect the baseband portion of the cellphone, including frequency of operation and whatever codes are necessary to identify itself (IMEI) and to access a particular network (T-Mobile, AT&T, Verizen).  Again, it is clearly more than just flash memory.So my question is, how exactly do they work, and how can I get into my own card?
How does a SIM card work?
firmware;memory
SIMs card are a type of Universal Integrated Circuit Card (UICC).how exactly do they workAccording to Karsten Nohl's presentation Mobile Network Attack Evolution, SIM cards contain an embedded real-time operating system, a filesystem and a Java VM:Here is the technical specification for UICCs, which describes exactly how they work: ETSI TS 102 221 V8.2.0 (2009-06)Technical Specification for smart cards, the UICC-Terminal interface and physical and logical characteristics.how can I get access to the data?  how can I get into my own card?This DefCon presentation DEF CON 21 - Karl Koscher and Eric Butler - The Secret Life of SIM Cards video explains quite a bit about SIM cards and how to interface with them.From the presentation slides:They also had trouble:They found SIM Alliance Loader software......but decided to use GlobalPlatform instead, which is far more complicated. In order to use GlobalPlatform to interface with the SIM card, the presenters drew on techniques presented in Karsten Nohl's research.