The twins ready and tested Tomorrow shipping.As suggested by Zozo no jumper RB0.
On the original Bridge the 9V replaced by GND. At this situation the RB0 connect GND to GND. No problem if missing.On Hungarian Bus extenders the 9V still present on the sockets, then RB0 make a short circuit if present.
I got the Emulator, and it is working, loading games from SD Card
Are you loading Spectrum games from the SD Card? How are you doing that?
:ZX game.TAPOr when enter LOAD "" in Spectrum mode, window displayed at bottom, then enter the filename (game.TAP). EXDOS commands (DIR, CD, etc) possible with :.TZX also possible if the game using standard ROM calls for loading.
Is to emulate ZX128 will be required changes in the circuit, whether it's just a matter of changes in the software ?
Does the lack of an answer to my question is that it was not noticed, is that a secret ?