SLIP driver for A/UX

[yue hang leung]

Is there anyone out there who knows where I can find a SLIP device driver
for the the A/UX?  I am working for a prof here who has a MacIIcx trying 
to run A/UX.  The problem is that the Mac is not on the ethernet network,
and so I can only use the serial line to hook up to the campus-wide network.
I know A/UX supports serial line communication, but where can I find the 
driver?  Does it come with A/UX?  I don't want the SLIP 'package'; I want
the 'device driver'.

Thanks for any info