[comp.windows.x] Keyboard Autorepeat Function

tjmurr@hubcap.clemson.edu (Tom Murray) (05/23/91)

Several of our X users are having a problem that we think might be related
to the keyboard autorepeat feature (the feature that controls whether a key
that is held down is automatically repeated; this feature is enabled
(disabled) by the `xset r on' (`xset r off') command.)

The symptom of this problem: characters autorepeat during normal typing at
times other than intended.  That is, characters are sometimes automatically
repeated two or three times in a row while typing text, aas inn thiiss
eexample.  It's as if some keys were occasionally sticking during use.

We have observed that all users reporting this problem are trained typists,
unlike myself, a hunt-and-peck typist who never has this problem.  This
observation might be coincidental.  However, our theory contends that the
problem owes to the typing style of these users--they perhaps apply too
much pressure to at-rest fingers and thereby momentarily depress the keys!

This description may sound funny but is definitely no joke.  One user,
in particular, has just converted from Sunview to X.  He is using the
same keyboard and claims he never, ever had such a problem with Sunview.
We gave this comment serious consideration, and have been wondering 
whether there is a program-controlled keyboard polling interval used to
detect depressed keys in support of the autorepeat function.  If there
is, perhaps Sunview sets a longer interval than X.

This problem has so far been reported only by Sun 3/50 keyboard users.
We run X11R4, and have found a C source file from X, sunKbd.c, located in
$TOP/server/ddx/sun (or mit/server/ddx/sun, whichever you find more
meaningful).  This C program declares a variable named autoRepeatDelay
and apparently initializes with a time delay value.  Is this relevant?
If so, can individual users change the length of this delay for their X
sessions?  How?  If we're barking up the wrong tree, does anyone have
any comments?

At the risk of sounding foolish (and BTW I'm relatively new to X myself),
Tom Murray
System Programmer
Clemson University
tom@cs.clemson.edu