Hi. I designed my own evaluation board for C51-derivates. For monitor communication I implemented an external 16550 UART that works fine when debugging my software. The UART-interrupt output is inverted connected to port 3.2 (INTR0) of my controller but I'm not able to stop execution after 'run' via the serial interrupt. The settings in uV2 seems to be correct. Do I have to modify INSTALL.A51? Do I have to add or change instructions for functions like SER_ISR, INITSERIAL, CLR_RI, CLR_SER_IE, SET_SER_IE, BEFORE_GO, AFTER_GO, ... ? Is there any example file for INSTALL.A51 solving my problem? Thanks a lot. Bernhard