Thanks Wolfme !
But, now I'm confusing more and more ... what the hell is this ???
I mean step 3 ???
I will analyse it in the code, red colour is my error "detection". I will update you.
Meantime, pls. start C64 with Run/Stop (KERNAL), step 1,
load some .prg files to SD card (games or so ...)
load SDCMDUC.PRG commander from other disk/tape/sd2iec ...,
Do you see firmware "UC64190124" on the top-left corner ?
Is there visible also "SD Card: OK" ?
Pls. navigate some .prg/.p00 files and press "Return" key ... it should start it
Is it working ?