Thee easiest way to access a Unix, most of the time anyway, would be  
through a dumb eterminal program (say, Terraterm or Hyperterminal).  
The nice thing about Unix and Unix-like OS's is that they're  
designed, not only for multiple users, but multiple logons and logons  
from remote places (i.e. not on the main console). Of course, there's  
always things like Emacspeak or YASR. For Linux, brltty and speakup  
are fantastic. So. Yeah, not only is it do-able, but it should be  
easy, unless he's required to use some software that runs in X- 
Window. That complicates things a lot.