@Sasa Djuric: the case is, yes right, an newer C64-case, which i've shortened. For the backside i've taken a wood board, which is shortened for the hole and tight with screws. It wasn't to problematic. This device is really small. It was again a precision job for installing all PCBs into it. > Nice 101! ...it is also a good syntheziser device e.g. for atmospherically sounds, but it can only play one instrument at same time, so it's an good device for masterkeyboard. @stryd_one: yes this was my own idea :) For fast working, i want to know, which IIC-Module is sending data to MIDI-OUT Ports. But i don't want to drill more hole on the case, so i used the holes from MIDI-Ports with a mount inside for LEDs. It looks nice.