Use vncserver to start a VNC server on an NMRFAM computer

If you are NOT physically logged into the NMRFAM computer, use vncserver to start a virtual desktop to run experiments remotely, process or analyze data

  1. Start a VNC server on the NMRFAM computer from your Mac OS-X computer
  • Open a terminal window on your computer: Launchpad > Other > Terminal
  • ssh to the gateway computer:

ssh <username>@login1.nmrfam.wisc.edu

  • Replace <username> with your NMRFAM username
  • Enter your NMRFAM password
  • ssh to the spectrometer computer (e.g. shami)

ssh shami

  • Enter your NNMRFAM password
  • Start VNC server with command:


  • Take note of the VNC server (or desktop) number that was started (e.g. shami:6).
  • Note that the first time you start a VNC server, the computer will request you to set a VNC password. This password can be set to anything and doesn’t have to be the same as the login password. To reset the VNC password, login to the spectrometer computer as shown above and type vncpasswd (it doesn’t ask you to input the old password to change it, so it’s not a problem if you forget it).
  • Note that setting the size of the VNC server window (by using the -geometry option) is not necessary as this can be automatically set by changing the size of the VNC window on your computer (see below).
  • Exit from NMRFAM computer


  • Exit from login1 (or login2) computer


  1. Access the VNC server from your Mac OS-X computer

On your Mac OS-X computer we are going to use TigerVNC to connect to the VNC server running on the spectrometer computer.

If you don’t have it already, download and install TigerVNC:

Open a terminal window: Launchpad > Other > Terminal

In the terminal window:

  • Navigate to the Mac OS-X subfolder of TigerVNC:

cd /Applications/TigerVNC\ Viewer\ 1.XX.XX.app/Contents/MacOS

  • Replace 1.XX.XX.app with the installed version of TigerVNC (e.g. 1.10.80.app)
  • Start the program “TigerVNC Viewer” with the ‘-via’ option to tunnel through login1:

./TigerVNC\ Viewer -via <username>@login1.nmrfam.wisc.edu fleckvieh:1

  • Replace <username> with your NMRFAM username
  • Enter the NMRFAM spectrometer computer and VNC server number started in step 1 above (e.g. fleckvieh:1)
  • You will be prompted (in the terminal) to enter your NMRFAM password
  • The next password requested (in a pop-up window) is the VNC password

A new window will appear with the desktop of the spectrometer computer.

You can now start topspin or vnmrj (or any other application installed there).

Expanding it to full screen will sometimes automatically resize the VNC window size to match the resolution of your screen.