Idek Tramielski provide the NOVA Graphiccard ET4000 Driver for the VOFA ET4000 Adapter.
The T0 Version is for 8-bit /256 Colour Cards and the T8 Version is for Hi-Color Cards.
When you have a card that doesn´t work ask Idek.
Cards that will not work are cards with a control PAL/GAL and cards with a GEN/SYN DAC.
There are also Drivers for the STGA ET4000 Adapter from Till Harbaum, ask Idek ...