Rubout processing

[HIC at MIT-MC (Howard I. Cannon)]

The problem is that LISP needs to run in order to send the proper control
codes to erase the character you rubout, whereas echo happens at system
interrupt level.  Thus, the other characters a printed by the system
"behind LISP's back".  MOON is working on a scheme which will correct this
problem in the system (it happens for MANY pprograms, and not only LISP).
The best bet is to either:
A) wait for the rubout to happen before typing
B) If things mess up, type a ^L [clear screen and redisplay] or a ^K
   [simply redisplay]

--Howard