Hello, I am running NT4(service pack 6) using the DOS shell cmd.exe. I am trying to invoke the C51 compiler version 5.5 (8051 Development Tools) using the gnu make utility version 3.79.1. I have set up a simple makefile to attempt to make a single object from a c file containing an empty main function. ---------------------------------------- # Test makefile test1.obj: test1.c c51 test1.c clean: del *.obj del *.lst ---------------------------------------- main() { /* this is a test file */ } ---------------------------------------- The make utility tries to invoke the compiler but gets somehow interrupted and nothing happens, and the prompt is returned. Even more strange is the actual properties of the dos window seem to be magically changed during this process too, the height of the screen memory buffer reverts back to 50 lines from the 500 I initially set it to. This all works perfectly when using win98 and win2000 machines and has also had the same failure on other NT machines with different user profiles. When the compiler is invoked directly from the command line it runs fine, only when called from gnu make. When the compiler is invoked from nmake it also works fine and when gcc is used in place of the keil compiler with gnu make it also works fine. It appears it is only the combination of the C51 compiler with gnu make that causes the problem, and only NT machines. It feels like some kind of memory violation to me. Has anybody come up against this before? Is there a work around or will I just have to use a more compatible OS? Regards, Alan