I did it, but didn't work. The options in [serial] were: serial1=directserial realport:com1 dbgirq dbgreg dbgtr dbgmd dbgaux I attach the log it generated:

I've downloaded mode.com from freedos. I used it with the winXP emulator (I think it's not possible to use it with dosbox), but my program didn't run. I have the version 0.72 of dosbox (last?). Any hint? Thanks Beni

I've just installed dosbox in my PC. I need to use an old program that controls a meassurement apparatus via com port. I installed the program in a dosbox session, without much problem. I connected the aparatus to com1 in my computer, and there is no error (with winXP DOS emulator it was inpossible …