I need to save the position of a stepper motor in non volatile memory.
I know that on the Arduino I have only 2 options for that kind of space and that are the EEPROM and Flash Memory as already nicely described at http://www.arduino.cc/playground/Learning/Memory.
The EEPROM has the problem of the write delay and the lifetime as I can easily have 1000+ steps per second and have to save the resulting motor position as often as possible, if possible with every executed step. That would easily exceed the EEPROM lifetime after a few hours of operation so it's not an option.
The Flash Memory with the PROGMEM interface appears to be read only. Is that correct?
What other options could you suggest?