This is incredibly helpful! Thank you Ryback.
So, how exactly did the process work with the original Doom? Was it like this-
You loaded the game on your PC, then before you played a level you put in the input command to record it like you mentioned above - doom2 -warp 01 -skill 5 -record nm01-005
Then after you completed it, you had a .lmp file you could share or put in a command to play it back for yourself?