[RTTY] PSK Info

[K4FJ at aol.com]

It looks like PSK is here to stay and many of the expeditions are using it  
either instead of RTTY or in addition to RTTY.  In other words, I am  getting 
the message to include it in my war chest.
 
I would probably use MMTTY with Writelog, but I am interested in reading up  
on how to operate PSK and how it works.  Is there available a good online  
source that you can recommend?
 
73, Steve, K4FJ