I have been doing a project using the 16C74A (actually using the Clearview Mathias emulator), and just changed to the 16C77, due to additional memory requirements. The getc() function doesn't seem to work any more, that is is hangs there and never returns any characters from the serial port. I suspect that I may have some problems with the #USE RS232 directive? Perhaps it isn't quite right, but worked under the 16C74A.(I changed to using the 16C77.H include file) Also, if I use #DEVICE 16C77 (or even #DEVICE 16C74A) I get a compiler error on the #USE RS232 statement. I am trying to use the internal UART. If I don't use #DEVICE, but just include 16C74A.H, it works fine. Any ideas? Could anyone email me some useful code fragments? Does anyone know anything about the inner workings of the serial routines with the CCS C compiler? Direct email, in addition to the list, would be appreciated. Thanks, Chris