In user-PPP, I begin a terminal session.  As I am entering the AT
initialization strings, the previous character typed does not appear (echo)
to the screen until I type the following character.  I type 'a', nothing
appears.  I type 't', and the 'a' (previous) appears.  Press ENTER and the
't' appears.  Press ENTER again sends a line feed to display.  I then
receive acknowledged response from modem, "OK".  I am able to continue with
dial and login authorization and get connected.  However, due to this echo
delay, it is very frustrating and virtually unuseable.  I have tried minicom
and other terminal emulators, and same pattern occurs.  How do I correct
this problem and get the character input to echo immediately to screen?

Thanks in advance.