For everyone interested int he hassle I had getting the code down to 5kb, here's the backup folder

http://www.swertvolc.de/download/tcrne12_code.zip (small)

in the folders are
- the original version in C-Script for A5
- the first running version in Lite-C for A8
- an already size and algorithm optimized version.

Directly in the folder you can check how messy code turned into a complete mess.

Fun fact:
The original demo was written in a short time with don't care about anything just get this thing done code.
The new version was written with a lot more time but with tiny and compact code which required some creative ideas.
Two different tasks