I have been following the post from dillyboy and found it interesting.
I too have need of a POS system for the raspberry Pi.
I did all of the installation instruction but got stuck in the removal of the tar files to the Pi for an old geezer like me, I also think that a step by step guide would not only be great but also desirable.
Please can you help in that respect.
It brings me back to the days when we used to make our own resistors and wind our own coils.
I am having loads of fun guys. Hats off to the guys at Cambridge