UniPCemu nullmodem cable

UniPCemu can use a special nullmodem splitting cable to emulate a full Hayes modem.

It's schematic is as follows:

The top-left port is connected to the client that's using the serial modem. The bottom-left port can be plugged using a terminating plug (connecting pins 4,5,9 together for proper grounding) or connected to a 4th serial port (which is left unused, as UniPCemu doesn't read the output of those lines).

UniPCemu settings

Connect the right hand side to a computer running a properly configured UniPCemu (with 2 serial ports used). Specify the main directserial port inside UniPCemu's settings file to be the upper port and the control port setup as the bottom port. Configure UniPCemu's serial port itself (using the setting menu or by modifying the settings file) as emulating a normal Hayes modem (the default setting). A nullmodem setting can also be configured (if required). Specifying the directserial with(out) the control port setting makes UniPCemu host a serial device on the specified physical serial port(s) instead of it's own emulated system (it's own emulated system having it's serial port disconnected instead).