MAME Cheat Sheet

mame nabupc -window -kbd nabu_hle -hcca null_modem -bitb socket.127.0.0.1:5816

You'll also need ROMs. Put nabupc-u53-90020060-reva-2732.bin in ./roms/nabupc (relative to where you're starting MAME from).

To make the simulated serial connection work, start MAME but at the intro screen when it says to press any key, press tab to enter the config menu. Go into Machine Configuration and set TX and RX Baud to 115200, and Stop Bits to 2.

Now run a NABU Internet Adapter listening on port 5816, and MAME should connect to it and boot.

Configuration files that allow the keyboard to work correctly can be found at https://forums.nabu.ca/viewtopic.php?p=26#p26.