GTK Serial I/O Questions

["T.L." <kj5xf worldnet att net>]

Greetings,
I was wondering if any of the GTK gurus that monitor
this list could lend a helping hand... :-)    I  am trying to
develop  a GTK  based  interface to a multi-mode data
controller which is connected to the COM3 (serial port)
on my PC.  I have looked through the archive and
didn't find anything that answered my question.....

So, here are my basic questions:

a) How do you get text out of a multi-line text widget and
     out to the serial port on COM3?
b) How do you get incoming data from the serial port (COM3)
     displayed in a text widget?

Any help/examples/suggestions would be appreciated.

Regards,
Tony L.