[ILUG] [Q] weird keyboard mode - how to exit? (and what is it?)

[Brian Foster]

  | Date: Mon, 13 Aug 2007 13:15:05 +0100
  | From: "Andrew Court" <syklops at gmail.com>
  | 
  | My theory had to do with screen, as you said anything you type is pre-ceded
  | with ctrl.

 not quite.  (sorry, pedantic point!)  I said:

   “I'm still not at all certain what it is doing,
    but it vaguely appears to be treating most(?)
    keys as prefixed with |control|; i.e., |d|
    seems to be treated as |control|+|d|.”

 that's a highly-qualified (tentative) statement:
 “not ... certain”, “seems”, “vaguely appears”,
 et al.  (and I've no idea at all what happens if
 I press, e.g., |2| — that may be illuminating.)

 rather more importantly, I'm not using screen(1).
 any hypothesis involving ‘screen’ should also
 explain how it suddenly started running, and how
 it is affecting all the virtual consoles _and_
 all(?) the X11 windows.
 ( in fact, I don't recall having run ‘screen˚ in
  anger, ever, and certainly haven't been on the
  very rare occasions this mysterious situation
  has happened. )

  |[ ... ]
  | If only a cold boot reset's it then it is unlikely to be a software problem.
  |[ ... discussion/example of non-discharging capacitor ... ]

 I do follow what yer suggesting, and I cannot
 rule it out.  but — and here I'm relaying on
 years (decades) of experience — this doesn't
 feel like a hardware glitch.  it _may_ be an
 incorrect programming of hardware by software,
 but (screwing my tin-foil engineering hat on
 tightly) this feels/smells mostly(? entirely?)
 software-ish.  such as some state which isn't
 reset on a (warm) reboot.  (it occurs to me I
 haven't the faintest idea how the BIOS reacts
 when this happens....  *sigh*, another test,)

  | What happens if you unplug the keyboard?  Is there any change?

 good questions!
 I don't know.  one serious hindrance is I don't
 know how to reproduce the condition, so until it
 happens again (and remember it is also very very
 rare, maybe once a month?), I cannot test those
 sorts of ideas.  (of course, what I _can_ test
 are ideas of how to get initiate the condition,
 which could be extremely illuminating!)

 the rareness may be a clew, but just what that's
 suggesting is opaque.  the situation _is_ known
 to involve |AltGr|, but my use of |AltGr| is also
 very rare (albeit less rare than the situation).

 as an aside, the last time I tried unplugging a
 USB keyboard, the keyboard did not function when
 I plugged it back in.  I had to reboot.  (that
 was a _long_ time ago, different keyboard and
 different Linux version.)  hence, this very
 sensible unplug test would be one of the last
 ones I'd try (assuming I still don't know how
 to reproduce), even if it's now the case I can
 unplug/replug the USB keyboard safely.

 I still like yer idea what's happening is
 something like an ISO 9995 alternative group
 keyboard layout.  a fair percentage of the
 pieces seem to fit that hypothesis?  I think
 I need to read up a bit more on both ISO 9995
 and X11(?) keyboards (e.g., learn exactly how
 to reliably check if such a thing is enabled,
 and how yer supposed to enter/exit any such
 alternative layout) ....   *sigh*

cheers!
	-blf-
-- 
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