Help: how to output to a port such as a RS232?

[Ron Schweikert]

In article <8380 at awdprime.UUCP> sjb at piobe.austin.ibm.com writes:
>In article <1991Jun11.135431.22955 at udecc.engr.udayton.edu>, Jinghong Li writes:
>> Help needed:  would someone tell me how to send output
>> to a port such as a RS232?  Any sepcial commands? 

other stuff deleted.

I responded to him by mail, but thought I'd post because I'm also interested
in communications.  I got a book by Sam's, called "C programmer's Guide to
Serial Communications" by Joe Campbell, ISBN 0-672-22584-0.

I haven't implemented any code with it yet, but while reading it I feel it's
quite comprehensive and informative.  

Have others read it?  Comments?  Do you recommend other books over (or in
conjunction with) to understand (and be able to write code for) async comm?