I've tried to analyze this small exe online.
Why the tool doesn't try to detect the set of instruction by itself? Dos program could run on architectures different from x86? The base address wasn't the same for every dos program?
I also tried with radare2 but it's really hard for me..
I've found this info through virustotal: File type DOS EXE Magic MS-DOS executable, MZ for MS-DOS TrID EXEPACK compressed DOS Executable (68.2%) TrID Clipper DOS Executable (10.5%) TrID Generic Win/DOS Executable (10.5%) TrID DOS Executable Generic (10.4%) TrID VXD Driver (0.1%) File size 63.16 KB (64680 bytes)
EDIT: thanks to the advice I used radare + a graphical interface called Cutter. It seems to work properly but I can't understand how to export the whole pseudocode