I read the thread and this is exactly what I was talking about. I'll try the patch or something else in cpu.cpp & report results Thank you very much

Thank you, I'll try to change things in this file. Dosbox supports Flat unReal Mode (*data* segments with 4GB limits). This real mode which permits to run 32 bits *code* is different : In protected mode, I load CS with a code selector where the 'D' Bit (bit 54) is set. I switch back to realmode …

Hello, I need to change the way dosbox remember the "Big" bit of the code segment between switchs from protected mode and real mode. So I ask where should I look to change this behavior (in the source code) and test with my test cases which doesn't work in dosbox currently ? Some precisions : …