obvious differences between old and new config you can run config with working directory /usr/sys/sysname; you don't have to be in sys/conf. if you're in sys/sysname, you don't even have to give the name explicitly. config doesn't remind you to make depend any more; it just does it for you. a few files have moved around: machine configurations are in sysname/conf, not conf/sysname. dev/conf.c is no more. config makes a conf.c for each machine. because conf.c (hence the device switches) are generated by a program, several kernel files have changed a little to make names regular: dev/kdi.c kmc.c sys/neta.c sysent.c sys3.c nami.c mp.c the inet sources have also been changed to separate tcp from ip (insofar as that's possible) there's a new file, /usr/sys/conf/devices, which lists all the device drivers (and line disciplines and filesystem handlers). it is used to generate conf.c.