Cub Linux as a kid’s computer

One of the things that my daughter wanted for Christmas was to be able to play some of the web games she’s seen on TV. I have a strict policy about not letting anyone touch any of my computers, so I rehabilitated an old HTPC for her to use.

The PC portion was mostly incidental; her main gift was her cool keyboard, cool mouse, awesome Pepa Pig headphones, and of course, her game subscription.

The donor PC was an old Intel Atom box with 2gb of RAM. This basically made Windows impossible. I toyed with the idea of using Lubuntu, but then I came across Cub Linux. It’s basically a lightweight version of Linux that boots to the Chromium browser. It’s like an [more] open source version of Chrome OS.

Getting the machine setup was fairly straight forward. I set it to auto-login and to go to sleep after a half hour. She knows how to turn the monitor off, that’s good enough for a 4 year old. I also installed VNC media player so she can watch cartoons that I have downloaded for her.

I almost always install Samba on Linux machines because it makes it easy to move files from Windows. The process is documented fairly well here. I just shared out the home directory like before so I could put videos in the Videos folder.

One problem with kids’ computers, especially for kids that are learning to use a computer while also learning to read, is that they need constant assistance. I use SSH for the low level operating system stuff, but a lot of it is just her not yet knowing what to do when something pops up on the screen. So I decided to share the desktop so I didn’t have to get up and walk over to the PC just to click OK or type in a password. One of the best tools for remote access to a Linux desktop is VNC.

VNC is a technology that I have been using off and on for years. I even used it on Windows in the NT and Win2K days before RDP basically obsoleted it. Every now and then VNC comes in super handy.

There are a number of ways to set up VNC, and a number of packages that deliver its functionality. Basically, you can run multiple X Window servers that let multiple users have graphical desktops at the same time. It can be super confusing for Windows users, so bear with me. Unix is multi-user. It’s meant to be used by multiple people at the same time. These users may be sitting at one or more physical consoles, virtual consoles, or remote shells. VNC is one way to get a graphical (window that you click with a mouse) console remotely on a system. You start a VNCserver on a given display x (:1, :2, :3. etc.) and then connect a VNC client to it on TCP port 509x (5091 for :1, 5092 for :2). Multiple users can run multiple servers and launch pretty much any number of graphical shells.

VNC is awesome, but a kid computer is seriously single user. What I need is to be able to pull up her Linux desktop on my [often] Windows desktop, without any intervention from her, and without getting up from my desk. She is still learning to use a computer, so I want to demonstrate things on her screen. Not getting up from my desk is important because she needs assistance fairly often. Also, I happen to be a lazy slug.

Fortunately, there is a tool for doing this known as X11VNC. The key difference for X11VNC is that it shares the physical console display, :0, which is the display of the user sitting at the keyboard. This is ideal because when I connect to her computer, I see what she’s seeing, and either of us can type or move the mouse.

To set up X11VNC, I first had to get the software installed from repos:
sudo apt-get install x11vnc

After you’ve installed it, you want to create a remote access password and then edit the config to start at boot. I use the same password for the remote session that I use to log into the user account. Thanks to the auto login, no one but me should ever have to type it in.
sudo x11vnc –storepasswd /root/.vnc/passwd
sudo nano /etc/init/x11vnc.conf

Then paste this into the editor:

# description "Start x11vnc on system boot"

description "x11vnc"

start on runlevel [2345]
stop on runlevel [^2345]

console log

respawn
respawn limit 20 5

exec /usr/bin/x11vnc -auth guess -forever -loop -noxdamage -repeat -rfbauth /root/.vnc/passwd -rfbport 5900 -shared

Then you can use any VNC Viewer to access the desktop remotely by entering the IP for the computer. My personal favorite viewer is tight-vnc.

With the remote access portion set up, I am now able to help her with her computer without getting up from mine. She has discovered that we can both type on the same computer at the same time, so a game has emerged. One of us types in a text editor and the other tries to delete what the other has written. It’s a race to either type or delete gibberish and she laughs like a maniac when we play it.