Hello Wolfgang, May be you have to add -lnutdev again at the end of the list of libraries in you application's Makefile. GCC has a one-pass linker. Harald At 22:20 11.08.2005 +0200, you wrote: >C:/ethernut-3.9.8/nutbld/lib\libnutdev.a(sja1000.o)(.text+0x12): In function >`CA >NBufferInit': >: undefined reference to `NutSemInit'