[net.emacs] CCA Emacs bug query

massar@godot.UUCP (J.P. Massar) (12/19/84)

The latest versions of CCA Emacs running on VAXEN with 4.2 seem to have
an incredibly obnoxious bug.  It was and still is present on CCA's own
version on a 780 and our version here at TMC on a 750.

Basically, whenever you type faster than Emacs can handle, there is the
possibility that when Emacs finally prints out your text, a character or
characters may be missing from the screen...  They are definitely in the
buffer since a C-L fixes the screen to be what you typed.  The worst of
it is you don't know whether you've made a mistake or Emacs has misplaced
a character!

My question is:  I have never seen anyone outside of CCA/TMC complain
about this.  Does this happen elsewhere?  Secondly, does anyone have the
faintest idea what might cause such behavior?  It seems to get worse as
the load average gets higher.  What, indeed, could cause such behavior?!?
If I even had a clue I might be willing to look at the code.

This behavior, in fact, has happened at least 5 (oops, 6!) times while
I've been typing this.  The load average on our 750 is 2.00.

(E.g., when I typed 'at least 5' I got on the screen 'atleast 5' but when
I C-L'ed the screen showed 'at least 5'.)

Help!

JP Massar
ihnp4!godot!massar
massar@cca-unix

martillo@mit-athena.ARPA (Joaquim Martillo) (12/26/84)

We  have  this  problem at Project Athena. We have another problem where
EMACS is run on a heavily loaded systerm and on type ahead  random  text
from  some  other  part  of  the  buffer or another buffer is put on the
screen. This text then goes away and something  like  the  correct  text
appears.

massar@godot.UUCP (J.P. Massar) (12/27/84)

In article <80@mit-athena.ARPA> martillo@mit-athena.ARPA (Joaquim Martillo) writes:
>We  have  this  problem at Project Athena. We have another problem where
>EMACS is run on a heavily loaded systerm and on type ahead  random  text
>from  some  other  part  of  the  buffer or another buffer is put on the
>screen. This text then goes away and something  like  the  correct  text
>appears.


Yes.  That happens at TMC and CCA also.  It is almost certainly another
symtom of the same bug.  It is less annoying once you realize what is 
going on but quite possibly very devatating on EMACS performance since
the screen is being updated needlessly (and wrongly) quite often.

No one, however, has yet suggested a cause or a fix...

JP Massar
ihnp4!godot!massar
massar@cca-unix