Hello I'm using the Atmel controller AT89C51CC03. I wrote an application which writes data to the internal EEPROM and the internal FLASH. If I run the application in the target system it is possible to write to the EEPROM and the FLASH. If I run the application in uVision3 the content of the memory window (addresses C:0x.... and V:0x....) always stays the same and it is not possible to alter EEPROM or the FLASH data. What is the difference between the simulation in uVision3 and the target system? Thanks for your help. Christian