Re: microsoft natural keyboard 4000 F10/Spell

[Marko Vojinovic]

On Monday 03 August 2009 22:06:01 you wrote:
>  > First of all, is it a PS/2 or USB keyboard? They are handled
> differently
>  > at the kernel level.
>
>  USB.  I had to buy a USB keyboard because this motherboard conveniently has
>  no keyboard plug and my old keyboard didn't appear to work through one of
>  those PS/2-to-USB adapters.  The marvels of modern technology. 
Tell me about it... :-@

>  "showkey -s" gives me no output at all when I press
> F10/Spell. 
This is because it's USB. From man showkey:

"The raw scan codes are available only on AT and PS/2 keyboards"

> From man setkeycodes: 
"USB keyboards have standardized keycodes and setkeycodes doesn’t affect them 
at all."

The "THEORY" section of man setkeycodes is a good read, btw.

>  "showkey" alone gives me keycode 432. 
Ok, so then the button does have a keycode, after all. One more reason not to 
trust xev... <sigh> :-) Did you try to put it into xmodmaprc and see if that 
works?

If it does, problem solved, if not, further digging is required, this time at 
the level of X. And X adds a whole new layer of complexity to keyboard 
handling. If it doesn't accept keycode 432 for whatever reason, someone more 
knowledgeable might be able to help, but I wouldn't bet on it too much.

>  It appears that I have a keycode but no scancode.  I don't know
> enough
>  about this to understand the implications. 
It's ok, since the keyboard is USB. The kernel seems to have something like a 
reverse lookup table for keycode-to-scancodes queries if it uses a USB 
keyboard. It seems the table is not complete, but it shouldn't be used by 
anything anyway, so it shouldn't be a problem.

The problem, if present, is with X, ignoring or swallowing this particular 
keycode.

>  The keyboard seems to remember the last state it was in between
> reboots,
>  i.e. if F-lock is on and I reboot the computer, it's still on afterward. 
>  So that's one good thing. 
Indeed. :-) If there was a way to control it from software (like num-lock 
status can be controlled), it would be even better. Did you happen to try that 
button in showkey? Does that produce a keycode? /* Somehow I doubt it does. */

>  This keyboard actually does have a little indicator light down at
> the
>  bottom along with the caps-lock, num-lock  and scroll-lock indicators. 
Consider yourself lucky. One of my keyborads doesn't have it, and I'm 
completely blind as to what will happen when I press F4 or such. As I am not 
the only one using the system, refraining from touching F-lock key doesn't 
help much.

Best, :-)
Marko

microsoft natural keyboard 4000 F10/Spell

[Marko Vojinovic]

On Tuesday 04 August 2009 01:02:00 Frank Cox wrote:
>  On Mon, 03 Aug 2009 23:46:37 +0100
>
>  Marko Vojinovic wrote:
>  > On Monday 03 August 2009 22:06:01 you wrote:
>  > > "showkey -s" gives me no output at all when I press F10/Spell.
>  >
>  > This is because it's USB. From man showkey:
>  >
>  > "The raw scan codes are available only on AT and PS/2 keyboards"
>
>  That's demonstrably inaccurate.  The other keys on this keyboard give me
>  results when I press them under "showkey -s".  It's just F10/Spell that
> has
>  no output. 
Let me quote man showkey again, this time more completely:

<quote>
The raw scan codes are available only on AT and PS/2 keyboards, and even then 
they are disabled unless the atkbd.softraw=0 kernel parameter is used.  When 
the raw scan codes are not available, the kernel uses a fixed built-in table to 
produce scan codes from keycodes.  Thus, setkeycodes(8) can affect the output 
of showkey in scan code dump mode.
</quote>

Basically, I would say that the USB keyboard does not produce scancodes but 
only keycodes, which are then translated back to scancodes if the application 
specifically asks for them. The translation is done via the fixed table built in 
the kernel.

So what you see in the output of showkey -s is in fact this translation, not 
the scancodes coming from the USB keyboard.

Since you got me interested in this problem, I did some digging of my own, and 
found out that the X server is the one (probably only?) major app that *does 
not* use keycodes, but rather scancodes directly. This describes exactly the 
problem you see, since the kernel table above does not seem to have a scancode 
map of keycode 432. If that gets fixed, your key should start working 
automagically under X, and you will be able to read off the X keycode using 
xev.

Btw, keycodes as read by showkey and keycodes as read by xev need not be the 
same, since X creates a different mapping from scancodes to keycodes than the 
kernel. The former are called "Linux keycodes", and the latter "X
keycodes". 
You can read more about that in the appropriate HOWTO:

  http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO.html

Now, how to fix the missing scancode in the kernel table is a different issue, 
since the table seems hard-coded into the kernel. The above paragraph from man 
showkey *suggests* that it just might be possible to use setkeycodes for your 
advantage, regardless of its intended usage --- find an unused scancode 
sequence, do a

setkeycodes <scancode in hex> 432

and see if this scancode will be recognized by X (using xev). Now, if xev sees 
this scancode, it will assign to it a new, probably different keycode, which 
you can then use in xmodmap. If this works, great. If not, maybe a small patch 
to some kernel source file and a recompile of the kernel would solve it. 
However, I believe this is interesting enough to be reported to the kernel 
developers, either as a bug, a rfe or just a question on their mailing list. 
Just tell them that showkey reports a keycode 432, and there is no matching 
scancode in their keycode-to-scancode mapping table, which renders the key 
unusable under X. Maybe they will provide a proper fix.

If you open a bug against the kernel about this or contact the devs on the 
mailing list, please post a link to that here, I am quite interested in 
following the discussion.

HTH, :-)
Marko

microsoft natural keyboard 4000 F10/Spell

[Frank Cox]

On Tue, 04 Aug 2009 05:02:07 +0100
Marko Vojinovic wrote:

>  If you open a bug against the kernel about this or contact the devs
> on the 
>  mailing list, please post a link to that here, I am quite interested in 
>  following the discussion. 
https://bugzilla.redhat.com/show_bug.cgi?id=515406

-- 
MELVILLE THEATRE ~ Melville Sask ~ http://www.melvilletheatre.com

microsoft natural keyboard 4000 F10/Spell

[Frank Cox]

On Mon, 3 Aug 2009 18:02:00 -0600
Frank Cox wrote:

>  xmodmap -e "keycode 432 = F10"
>  
>  xev shows no output when I press F10/Spell after entering the above
>  command.
>  
>  xmodmap -pke shows keycodes only up to 255, so 432 is probably an invalid
>  number for that purpose anyway, though it doesn't show any error when I assign
>  it as shown above. 
I just found out why:

 xmodmap -n -e "keycode 432 = F10"
! dump of work queue
        keycode 0xb0 = F10

And sure enough, xmodmap -pke shows me this:

keycode 176 = F10

So xmodmap wraps the 432 and changes keycode 176 (hex b0) to F10 instead of




-- 
MELVILLE THEATRE ~ Melville Sask ~ http://www.melvilletheatre.com

microsoft natural keyboard 4000 F10/Spell

[Frank Cox]

On Mon, 03 Aug 2009 23:46:37 +0100
Marko Vojinovic wrote:

>  On Monday 03 August 2009 22:06:01 you wrote: 
>  > "showkey -s" gives me no output at all when I press
> F10/Spell.
>  
>  This is because it's USB. From man showkey:
>  
>  "The raw scan codes are available only on AT and PS/2 keyboards" 
That's demonstrably inaccurate.  The other keys on this keyboard give me results
when I press them under "showkey -s".  It's just F10/Spell that has no
output.

>  Ok, so then the button does have a keycode, after all. One more
> reason not to 
>  trust xev... <sigh> :-) Did you try to put it into xmodmaprc and see if that 
>  works? 
xmodmap -e "keycode 432 = F10"

xev shows no output when I press F10/Spell after entering the above
command.

xmodmap -pke shows keycodes only up to 255, so 432 is probably an invalid
number for that purpose anyway, though it doesn't show any error when I assign
it as shown above.

I think I'm outta luck.  I have no idea what's so special about F10/Spell when
all of the other F-keys are recognized by xev.

>  It's ok, since the keyboard is USB. The kernel seems to have
> something like a 
>  reverse lookup table for keycode-to-scancodes queries if it uses a USB 
>  keyboard. It seems the table is not complete, but it shouldn't be used by 
>  anything anyway, so it shouldn't be a problem. 
Since the other F-keys work, maybe there's something missing in that kernel
table, somehow.

>  The problem, if present, is with X, ignoring or swallowing this
> particular 
>  keycode. 
And only that keycode.

>  Did you happen to try that  button in showkey? Does that produce a
> keycode? 
No keycode.  It just turns the F-lock light on and off.  I think it's some kind
of a hardware switch. The keyboard documentation implies that it's a hardware
switch that's not under any kind of software control.

>  Consider yourself lucky. One of my keyborads doesn't have it, and
> I'm 
>  completely blind as to what will happen when I press F4 or such. As I am not 
>  the only one using the system, refraining from touching F-lock key doesn't 
>  help much. 
I never look at my keyboard when I'm typing so it's always good for a surprise
if I hit the F-lock key by accident, especially because I'm not using that area
of the keyboard too much in the first place.  I might turn it off by mistake and
not notice for the next three hours.


-- 
MELVILLE THEATRE ~ Melville Sask ~ http://www.melvilletheatre.com