I am into a project where I store the data received from ethernet to a file in SD card continuously with HIGH SPEED. I am using http://mbed.org/users/Blaze513/programs/SDCard/ll0qj8 library. I can only use this SD card program: http://mbed.org/users/Blaze513/programs/SDCard/ll0qj8 The FAT library has to be taken from the above link only. The FATFileSystem library from mBed doesn't works with SDCard.cpp-----> LIBRARY 1 I tried with other programs and libraries like SDHCFileSystem and SDFileSystem, Ex: http://mbed.org/users/chris/programs/SDCard/60euc-----> LIBRARY 2 But here are the problems. 1. With using Library 1 in program, the file storage works perfectly, but if SD card is not inserted while powering mBed, then program will not run in mBed. To make the program run, either SD Card has to be inserted before powering ON mBed OR if sd card is not inserted, mBed has to be connected to PC via USB (interrupt???) so that mBed will run without SD Card 2. With LIBRARY 2 and all other SD Card libraries, the data is stored to SD Card for around 5-10sec and then stops storing. I have tried with different SD cards and sample program from the forum for SD Card libraries, but same behaviour. Data will be stored for 5-10 sec only, then no communication between SD card and mBed. BUT with these libraries, I can run mBed program without inserting SD Card while power up unlike in LIBRARY 1 My requirement is, mBed program should run until (fopen()) if sd card is not inserted during power up, which doesn't happens in LIBRARY 1. Thanks