🚀 go-pugleaf

Hello,
 
  A few days ago, my boss posted a question needing some info
on setting up/initializing the com port and read/write howto's.
After digging through the code we got from replies, we found that the best way 
to do this was to use some code that would actually access
the UART? directly, install an interrupt handler for the 
Data Available Interrupt.  Now, the problems we had came from
the fact that the original code we got, checked not only for
the Data Avail. Int, but also the Modem Status Int and the Receiver
Line Status Int.  In test runs, when these to interrupts were handled,
our little 'teeny terminal' program hung.  However, when these two
status ints were 'ignored' (by unsetting them in the Int. Enable Reg.)
then things went fine. (i.e. we could dial up some place, log in,
do a few directory listings).  My question is, what, precisely, are these
status interrupts for, and are they absoultely necessary?  I'm
no PC techie, which is why I ask the Real PCers' (c.o.m.p ) :) 

Thanks for any help.

Russ