New F11 for XO-1.5 build 48

Christoph Derndorfer christoph.derndorfer at
Mon Nov 30 18:49:16 EST 2009

Hi again,

On Mon, Nov 30, 2009 at 7:21 PM, Chris Ball <cjb at> wrote:

>   > Another observation is that the dimming of the screen kicks in
>   > after about 20sec of inactivity but it takes another 5sec before
>   > suspend really happens. I for one find these timings slightly
>   > confusing and don't really see any advantages of having two
>   > seperate intervals for those two operations. (But maybe I'm
>   > missing something here...)
> Maybe I can get them a bit closer together.  There are a set of things
> we want to do when we think we're about to suspend, though, and that's
> what the two stages are for.  It also serves as a warning to the user,
> I suppose -- "if you don't want to suspend, move the mouse now".

Well, that explanation is basically what I thought of when writing "maybe
I'm missing something here"... ;-)

But admittedly I remain unconvinced. On my Windows Vista setup the
screensaver actually starts a couple of seconds before the session is locked
so moving the mouse within that short interval keeps me from having to
re-enter a password. So in that case I think that having two different
intervals makes sense.

However in the case of the XOs with basically instant resume I don't really
see the advantage of distracting a user by reducing the backlight (which,
from what little I understand about human attention, will indeed distract
users from the actual content of the screen). The advantages in terms of
energy use must surely be tiny given that we're talking about 5sec of
reducing consumption by maybe 0.5W.

On the other hand turning off the backlight completely after a certain
amount of time as a first measure to reduce power consumption strikes me as
an interesting alternative to the current implementation...

Good night,

Christoph Derndorfer
co-editor, olpcnews
e-mail: christoph at
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