Help needed with IBM VFD pole display

[maddoc]

It is an IBM FRU 10J0268  or P/N 10J0267 POS pole VFD display.
It uses an IBM proprietary serial protocol over RS485, takes power from a 12V source through the same cable.

Inside it has a Futaba M202MD08A board and VFD.
Other inscriptions on the board:
1P00A288-01 REV.D
KU-02194V-0 N

Between the RS485 transceiver and the display controller (Toshiba TD62C950RF) is a chip "VFD11 copyright IBM99".
This translates the serial commands from the RS485 transceiver to the display controller.

When powered up it displays U001 on the left part of the second line (2x20 VFD).

So far I haven't had any luck to display something.

There isn't anywhere a datasheet for the display controller TD62C950RF, for the IBM chip VFD11, or how to communicate with this display from IBM.

Please, if you have information about this type of displays or have any of the datasheets, or at least have a working one and can sniff the communication line, help me!