Nandblasting not working in one xo

[Roshan Karki]

Thank you very much John for the explanation and all the help. :) G'day.

On Tue, Jul 10, 2012 at 9:33 AM, John Watlington <wad at laptop.org> wrote:

>
> NANDBlaster uses a fixed transmit speed (modulation).
> If the signal budget for a laptop isn't sufficient to support
> that speed, it will fail to receive many packets.
>
> When using normal WiFi, the transmit speed (modulation)
> is decreased until reliable communication can be obtained ---
> therefore a laptop with decreased signal budget (e.g. bad antenna)
> may still work, although with degraded performance.
>
> Regards,
> John
>
> On Jul 9, 2012, at 11:10 PM, James Cameron wrote:
>
> > That the antenna change did not work shows the problem is in the
> > wireless card.
> >
> > You asked why not use the same mechanism as Sugar?
> >
> > Consider the transmitter performance.
> >
> > Your network used by Sugar probably has an access point with higher
> > transmit power and better antenna than the laptop being used as
> > NANDblaster sender.
> >
> > So it is perhaps the combination of small damage to one laptop and
> > large damage to another laptop, that causes NANDblaster to fail.  But
> > the combination of good access point and large damage causes Sugar
> > networking to be successful.
> >
> > See http://wiki.laptop.org/go/Antenna_testing#Link_Budget for a
> > calculation of wireless success, to see what variables are important.
> >
> > Does Sugar in ad-hoc wireless mode work between the two laptops?  Or
> > Sugar in mesh wireless mode with no other laptops nearby?
> >
> > If so, that's very interesting.
> >
> > Open Firmware and Linux use different commands sent to the wireless card.
> >
> > I've checked, and we are using the same wireless firmware 5.110.22.p23
> > in both Open Firmware and Linux (build 883).
> >
> > Daniel, do you know of any commands that the Linux kernel may have
> > sent to the card that may improve signal, even by accident?
> >
> > On Mon, Jul 09, 2012 at 04:06:16PM +0545, Roshan Karki wrote:
> >> I tried with antenna change but as you told, didn't work. So I think
> this is
> >> the dead end. Thank you for your help. But one question I wonder is in
> Sugar I
> >> can use very poor network very well. Why not use the same mechanism in
> OFW as
> >> well?
> >>
> >> On Fri, Jul 6, 2012 at 10:41 AM, James Cameron <quozl at laptop.org>
> wrote:
> >>
> >>    G'day,
> >>
> >>    Thanks for the photographs.  There's nothing wrong that I can see
> >>    either.
> >>
> >>    Repair may attempt antenna change, but it is unlikely to be fixed
> with
> >>    only antenna change.
> >>
> >>    Perhaps the radio module has been damaged.  On XO-1 the module is
> >>    soldered down and is impractical to replace.  In later models
> (XO-1.5,
> >>    XO-1.75) the module is in a socket.
> >>
> >>    --
> >>    James Cameron
> >>    http://quozl.linux.org.au/
> >>
> >>
> >
> > --
> > James Cameron
> > http://quozl.linux.org.au/
> > _______________________________________________
> > Devel mailing list
> > Devel at lists.laptop.org
> > http://lists.laptop.org/listinfo/devel
>
>
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