-r listen-port, -Z listen-port
The emulator and sdcdb communicate through a network socket. This option switches the debugger
from communicating through stdin/stdout to listening on a specific network port instead. Once a
connection is made, the debugger continues on, using that network port for command input and
output. The debugger uses port 9756, and attempts to connect before launching ao-dbg, so if ao-dbg
is listening on this port before sdcdb is started, sdcdb will end up talking to the existing ao-
dbg instance. That's often useful for debugging ao-dbg itself.