How to debug a DOS program?

Question

DOS

Hello.
One fine winter evening, a friend turned to me - they say, help me out, friend, there is a program from which I need to pull out the formulas, there are no other sources.
The program is written in Turbo Pascal: a blue window with several steps and only text output (via WriteLn and SetCursorPosition int 10) and input via Intr.
Ida recognized the executable as NewExe(Os/2), issued disassemblies normally. Hex-Rays refuses to decompile 16bit. There are a lot of calculations in the code through the FPU, and in connection with this, the questions are:
1) How to debug this business? Turbo Debugger crashes inside int 2F. (DosBox emulator). The debugging option over the network is very slow - there is a lot of code. I would like a separate debugger for Windows with the ability to interact with the DOS emulator.
2) Are there any id plugins that would convert assembler code into readable formulas?
3) Is there any decompiler for 16bit NE.ExE programs?
Thanks in advance)

Answer 1

Just in the era of the dawn of Turbo Pascal, the dawn of decompilers-debuggers also began. At one time, SoftICE thundered.
old-dos.ru/index.php?page=files&mode=files&do=list...
But, most likely, Hiew will suffice. Latest free version 6.11
To the heap:
AFD 1.0
Periscope 5.31
Quaid Analyzer 9.0
Sourcer 8.01

Answer 2

If it's Turbo Pascal chances are it has the appropriate signatures for FLIRT in the idea. Debugging in a virtual machine does not work - debug on real hardware.