Tet 42 is an obsessed game for me since I was a child however I can't pass a specific level because my computer is fast. I can't pass 103. level because it's impossible to pass that level(s) with that speed. DosBox gives me a solution by its ability of speeding down the game but I can't use it since I can't play the game in DosBox! The game starts but in order to play, F1 button has to be pressed but F1 has no effect to the game in DosBox! I tried to attain other keys to F1 by using keymapper but still nothing..
Please help me is you know a way out.. I really need this and finish this game!

Thanks..