Benjamin Khan wrote:

I also need the solution to be non-volatile, i.e. in case of power outage the 2k message should not be lost.

There are already lots of hints on how to do this (EEPROM, battery backed RAM, etc.) in some of the other posts. Maybe one of those ideas is what you need.

Here's another idea that is a little bit different. Suppose that you would rather not include any non-volatile memory for some reason. (Too expensive, writing or erasing is too slow, don't want to worry about exceeding the write cycle limit, etc, etc., etc.)

Would it work to simply signal the modem every time the microcontroller powers up and download a fresh copy of the message to be displayed? If that was possible, it would eliminate the need for the non-volatile memory. It would also eliminate all the nasty problems related to losing power during the message download.

-- Russ