This application needs the users to access serial and/or parallel port in RW mode, depends upon the programmer is used. So, administrator have to add allowed users to uucp and/or lp groups. To do this, type the following command line: useradd -G lp,uucp allowed_user for each allowed_user you want to add. And if a parallel port programmer is used, you need to load the ppdev module, by typing the following command line: modprobe ppdev If you want to use the SDCC Compiler with Piklab, you have to modify the PATH for the whole system, not only for a single user. So, you have to add the following: PATH=$PATH:/usr/libexec/sdcc in /etc/profile, before the command line export PATH