VRPN 07.15
How to acknowledge VRPN in your papers
UNC "Python" connector for up to 5 buttons on a parallel port
This lets you connect up to five buttons on a parallel port, using the "sense" lines to red the buttons. Its use is deprecated (use the TNG3 instead). UNC makes no claims to the fitness of this circuit for any purpose. We make no claims to the safety of this circuit (there is no overvoltage protection, for example, and it may blow out your parallel controller or motherboard). It is provided here for documentation purposes internal to UNC only.
User question: It seems like some root-level config may be needed to make the port /dev/lp0 available for this use-- what steps do I need to take?
Roman Shulakov's answer: PAM security modules take care on that.
Normall practice is to change
ownership of the ports to the user logged at X console so that she/he
gains full control over. You put (being the root) the following lines
into /etc/security/console.perms
<serial>=/dev/ttyS[0-3]
<parallel>=/dev/lp[0-3]
...
<xconsole> 0600 <serial> 0660 root
<xconsole> 0600 <parallel> 0660 root
Should it doesn't work a quick (yet insecure) hack would be to change
the permission for your port so that everyone on a system would be
allowed with access.