"Physics with XO" by Guzmán Trinidad now available in English

James Cameron quozl at laptop.org
Mon Jul 4 03:18:52 EDT 2016

On Mon, Jul 04, 2016 at 01:16:26AM -0500, Sebastian Silva wrote:
> If you find anything that can be improved, do let us know; it will
> be appreciated.

Quoting from

> It is important to highlight that at the moment of finishing this
> investigation we detected an important problem with this model: When
> the TB Activity attempts to measure voltage or resistance in one
> channel, it randomly obtains the readings belonging to one channel
> or the other; this problem makes it impossible, for the moment, to
> use the applications that involve these measurements. In queries
> made about this issue, we were informed that it is a low level error
> ("bug") that is being worked on.

And also from https://icarito.gitbooks.io/physics-with-xo/content/annexes.html

> At the time of finishing this work, this model consistently fails in
> the following way: when running any TB program it may measure the
> correct channel (generally CHL) or it will randomly return
> measurements coming from the other channel (CHR) (this error is
> generally known as swapping). This causes programs that measure
> volume, frequency, resistance and voltage to either function
> properly or not. Having made the query to the experts, we were
> informed that they were working on a solution involving low level
> modifications to the XO.

Both of these were the same underlying cause, were fixed last
September, and the fix is in OLPC OS 13.2.7.  Please upgrade kernel or
operating system.


(removed CC for lists not subscribed).

James Cameron

More information about the Devel mailing list