I [@CONSULitAS](https://github.com/CONSULitAS) tested the changes on my K8200 with 20x4-LCD and Arduino 1.6.12 for Mac (SD library added to IDE manually), 2016-11-18 - everything works well.
**Source for genuine [Vellemann Firmware](http://www.k8200.eu/support/downloads/)**
* V2.1.1 (for z axis upgrade, date branched: 2013-06-05): [firmware_k8200_v2.1.1.zip](http://www.k8200.eu/downloads/files/downloads/firmware_k8200_v2.1.1.zip)