Hello, this is my error message: Connected to Monitor-51 V2.1 Load "C:\\hw\\a51\\serlinka\\serl" MONITOR ERROR 22: NO CODE MEMORY AT ADDRESS 6931H It is true, there is no physical memory at this addres, but in my point of view there is no need to write this location. My code range is 0xA100 to 0xB799 and it is large enough for my code. Someone knows advice? Thanks P.