I had developed some C++ code in the mBed compiler for the LPC1768 and exported it to a Keil uVision project. After doing this and testing my software and coming up with working code for the 1768 mBed dev board I had a prototype board built with the 1769 and compiled the hex file in uVision after chaning the target micro to the LPC 1769 but when I install it does not work at all. So then I developed a simple program that would flash the LED on the dev board on the 1768 and that worked. I exported it to uVision and changed the GPIO to a different pin to control the LED and changed the project to the target 1769 micro and that does not work either. If I use the standard C library, the Keil LPC17xx_startup.s script, and the 17xx header file I can get the heartbeat to work with no issues. I think there is something in the mbed library that causes the 1769 register mapping to be off because I can't get anything to work on the 1769 with the mbed library.