com ports in freebsd

[Duane Winner]

Hello,

I have a question about how FreeBSD handles the serial ports.

After messing around for 2 days, I finally got my PCMCIA modem working
on my laptop. All I really had to do was to
"cd /dev/ && ./MAKEDEV cuaa4"

I did this because dmesg kept reporting the Megahertz modem at "sio4".

What I don't understand is the why or how. My kernel config is still
using the default sio0 thru sio3 devices:
	device          sio0    at isa? port IO_COM1 flags 0x10 irq 4
	device          sio1    at isa? port IO_COM2 irq 3
	device         sio2    at isa? disable port IO_COM3 irq 5
	device         sio3    at isa? disable port IO_COM4 irq 9

So if there is now sio4 in the kernel, how is this working?

I'm not complaining, nor looking for a solution, since I have everything
working now.

I'm just trying to understand how this working.

Thanks,
DW