I've got the serial cable that came with the unit. It works just fine with the system not in the cage. With the unit in the cage, the connector is male/female reversed.

Oh OK, it's been a while since I had the cage around.

You can connect two female connectors to each other by sticking some bare wires or even paperclips into the right holes. Best to get a real cable, though, if bad ones crash your empeg...

Borislav