input devices

[lee]

"T.C. Hollingsworth" <tchollingsworth at gmail.com> writes:

> On Sat, May 24, 2014 at 9:18 AM, lee <lee at yun.yagibdah.de> wrote:
>> what would be the device for a Kensington Slimblade which is connected
>> to a PS/2 port with an USB-->PS/2 adapter?  The device doesn`t seem to
>> appear anywhere when connected like that.
>
> It should appear like any other PS/2 mouse.  If it does not appear,
> your mouse does not support the PS/2 protocol.
>
> Most USB-to-PS/2 adapters are passive converters, and require the
> device itself to speak the PS/2 protocol.  Many keyboards and mice
> were (and some still are) designed to speak both the PS/2 and USB HID
> protocols so they can be used with such passive converters.  Most new
> ones (e.g. this decade) only speak USB.
>
> If you really must use the PS/2 port, they do make _active_ adapters
> that work with any sort of device.

Oh, ok, that`s probably the problem I have! I need a different adapter
...

I knew there are "active" adapters but I didn`t find out what that
actually means and thought it might have to do with supplying power to
the device.

I don`t /have/ to use PS/2, but I /want/ to use PS/2.  USB devices must
be polled, which makes them slow.  Using USB for this has only
disadvantages, with the only exception that the devices can be
hotplugged.

>> And what are virtual keyboards for, and why do I supposedly have two
>> power buttons?
>
> The XTEST devices allow for the X server to be tested/used without
> real hardware:
> http://www.x.org/releases/X11R7.7/doc/libXtst/xtestlib.html
> (While the interface may have been built for testing purposes, I
> wouldn't be surprised if it is used for other reasons these days, like
> virtual desktop software.)

Some software like vnc seems to require it ... I`ll have to see what
happens what I disable all the testing extensions; there doesn`t seem to
be an easy way to disable only XTEST.

> Power buttons are implemented as "keyboards" because X has no better
> way to let your desktop environment know you've pressed it, seeing as
> how it dates back to the days where most computers had actual switches
> that really cut power immediately.
>
> As for why you have two, some motherboards have two plugs for them, or
> a special little internal power buttons on the motherboards
> themselves, or are just poorly engineered and say they have two when
> they really have one.  :-)

Ah, yes, my board has a power button on it.  I never use that and forgot
about it ...

Thank you for all your explanations, that was really helpful! :)


-- 
Fedora release 20 (Heisenbug)