I actually burned an eprom and tried it in my real Delta-1, but didn't succeed.
Found out the both CHIP ENABLE's are somewhat different than standard mask-roms. ROM dump was the same as ma_winke_y1d.

And I believe the real Delta-1 does indeed access the table, because it's doing something with these chip enables. So the error should be in the MAME emulation, and I did only correct it for MAME.

When I let Delta-1 (original) start as white, it shows the same moves as Boris rev1, but on the emulation it's plays very differently.

Hi,
I let Arena play two games (15s/move) between both versions.

As black, Bataais' hacked version cleaned up material, reaching an overwhelming king + 2 rooks, 1 bishop, 2 knights and 4 pawn against genuine Delta-1's isolated king - but the game ended in a draw (3-fold rep).
As white, the hacked version won by checkmate with a large material advantage (king + 1 queen, 1 rook, 1 bishop, 1 knight, 4 pawns against king + 1 rook, 1 bishop, 1 pawn).

How to play both: surely many ways, this one is quite simple
- in MessChess, I created a hacked_roms new directory containing Bataais' ROM
- in Arena, I duplicated my Delta-1 engine and updated each with command line parameters:

ccdelta1 -rompath roms
ccdelta1 -rompath hacked_roms

You need to specify both, as without -rompath parameter the default is used from ccdelta1.ini file, where the latest used configuration is memorized. So better force it, or you will end using the hacked one anyway.

Of course, on hacked engine start, you need to manually skip the warning about the unexpected ROM.

Have fun,
Eric