Keycodes >0xff

Michał Pytasz mpytasz at
Tue Jun 14 19:07:59 EEST 2005


Thanks for reply.

On Tuesday 14 of June 2005 17:42, you wrote:
> Yes, keycodes are limited to 248 (8 codes are reserved for other uses).
> We did not forsee any keyboards with more than 248 unique keys; you'll
> need to use codes that are not otherwise in use.  So scancodes will need
> mapping to keycodes in some fashion, rather than being one-to-one.
> I challenge you to show me a keyboard with more than 248 actual keys on
> it.

I never said that I have keyboard that has >248 keys. What I meant was a 
system returning high scancodes (up to 0x1ff ). I was trying to add some 
universal (non confliting with other keyboard models) solution. It won't be 
hard to find an unused (for this specific keyboard) keycode but it is not 
said it won't (ever) be used for any purpose in another device. 

Am I right I sould start playing with xkb/keycodes/aliases and add there an 
alias for example for "creative" (or where could I find some specification or 
a howto in this matter, most links I "googled" said how to set up keyboard in 

Can (in xkb files or anywhere else) be done permanent mapping just for this 
keyboard model (and 3 of its keys) ? 


> Note that each keycode can have arbitrary keysyms associated with it.
> 				Regards,
> 					- Jim Gettys
> On Tue, 2005-06-14 at 17:31 +0200, Michał Pytasz wrote:
> > Hi,
> >
> > I'm new to this list, and not sure if it is the right place to ask my
> > question. Recently I prepared an additional keyboard layout for Creative
> > wireless desktop 8000 for X (and posted to bug 3514)
> > but there is one thing that makes me wonder.
> > Are the keycodes for X limited to 255? (one byte) If not how to add keys
> > with scancodes 278-280 (0x116-0x118) ? <linux/input.h> allows 9 bit
> > keycodes (max 0x1ff) this is the reason for my question, since in X, keys
> > with scancodes
> >
> > >255 remain dead, trying to add (in xkb/keycodes/xfree86) additional
> >
> > scancodes and increasing maximum made all additional keys of the keyboard
> > dead.

More information about the xdg mailing list