Can anyone else verify that the Hello example fails to output to the serial#1 window when the reg515a.h is included. Single stepping through the program I can see the characters being written to SBUF but nothing is displayed in serial#1. Just by replacing the statement "#include <reg515a.h>" with say "#include <reg552.h>" the program works just fine.
Thanks for all your help. I just created a new project and brought over my .c and .h files. It occured to me that it could have been a corrupted include file, so I copied over a new reg515a.h from the keil web site. It works now.
Do you know if it was a corruption in your file, or was there an error which Keil have fixed in the latest version?