It took long as I was balancing from one solution to the other.

The incorporated Flash was small and difficult to manage as it was needing a large buffer in RAM but it had the advantage of being already inside the terminal

On the other end the SD card was large enough to store many files, the block allocation and wear leveling was managed by the card itself but the terminal needed to be modified.

I finally choose the SD card. It has another advantage, the card can be extracted from the terminal and the files can be saved and edited on any computer which is great I think.

I have made some modification in the terrminal:

• desolder the Flash
• Connected a SD card reader
• Made some read/write tests

It works very well.

I am currently working on the software side implementing the SAVE and LOAD command. This commands are already implemented for an external I2C EEPROM. I am looking at keeping the same syntax to make the interface media independant.

The card reader is currently connected with flying wires. The next step will be mechanical modification in order to seamlessly integrate the reader on one side of the terminal.