Just few moments ago I have found quite interesting article that covers in details how the SIM card is build and works. Maybe for Terminal-side guys this is obvious but myself I found few new things for myself.
As the title says this is just introduction, more information could be coming.
follow the link to get more - resource.
Source:
Internet
As the title says this is just introduction, more information could be coming.
SIM Structure and File Systems
A SIM card contains a processor and operating system with between 16 and 256 KB of persistent, electronically erasable, programmable read-only memory (EEPROM). It also contains RAM (random access memory) and ROM (read-only memory). RAM controls the program execution flow and the ROM controls the operating system work flow, user authentication, data encryption algorithm, and other applications. The hierarchically organized file system of a SIM resides in persistent memory and stores data as names and phone number entries, text messages, and network service settings. Depending on the phone used, some information on the SIM may coexist in the memory of the phone. Alternatively, information may reside entirely in the memory of the phone instead of available memory on the SIM.
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| Fig. 1. SIM Card File System |
follow the link to get more - resource.
Source:
Internet