I try to use MON51 with my own target board. I create MON51.hex with the \\keil\mon51\install 7 20 00 to program my EPROM. I verify my v. Neumann aera with writing/reading code memory starting at 0x2000 and reports no problems. I compile/link my program with a startup.A51 file modified whith "CSEG at 3000" and in "option for target" in the uVision 2 BL51 Locate tab, I specified Code at adress 0x3000 to preserve space for monitor variables at 0x2000. When I download code to my board with option "go till main" the debugger hangs up and produced no response. When I want to stop the program, it seems that serial connection is lost and I have to reset the board. What am I doing wrong? Thanks. Jean-Luc