You seem to have a distribution which is using a device filesystem. I am not familiar with this system, but try to add a init script which creates the nodes for you. I have never used Slackware, and therefore I do not know which type of init is used there. Just browse the man pages; a good page to start is
$ man init
On certain systems, there is a
$ man init.d # At least SUSE has this...
Hope I could help somehow,