There are plenty of safe high-level languages in the world; JavaScript, for example. Rust is different: it's supposed to be safe and fast.

But Rust is slow. (And its type system hates you.)

Rust is slow because there is lots of hidden indirection ("smart dereferencing") and other hidden costs (ref counting, etc). In low-level C code I can look ( Read more... )

Over on twitter, Tim Caswell mentioned, "I think high-level scripting language on top of something like rust.zero would make for an amazing OS." and that set me off a bit. Twitter isn't a great place to write a reasoned discussion of programming languages or implementation strategies, so let's take a shot at it here.

As I've written about on ( Read more... )

Happy Thanksgiving! Here's SDR 0.7 to celebrate the holiday. Version 0.7 incorporates a number of dance engine refactorings completed shortly after the previous release promised them, as well as (more recently) a number of new call and concept definitions (and test cases) inspired by the C4 calls I am currently studying. I also updated Google ( Read more... )

An unruly tag team of OLPC folks gave a long talk on the Literacy Project today for attendees at this year's OLPC-SF Community Summit. It was streamed live on Ustream: Part 1 (Matt Keller, Richard Smith), Part 2 (Richard Smith, Ed McNierney, C. Scott Ananian, Chris Ball, questions from the audience). We've posted the slides: Matt Keller, Richard ( Read more... )

At IDC 2012 in June, Arnan Sipitakiat and Nusarin Nusen discussed how they are using Robo-Blocks-a turtle robot and “tangible Turtle Blocks”-to teach problem solving and debugging skills to 5- through 12-year-olds.

One of the things I learned from their presentation was that children had difficulty reasoning about relative angles. The Robo-Blocks ( Read more... )

Here's a first look at an XOrduino Turtle bot driving around:

I've checked out all of the functionality on the A1.5 board except the step-up voltage regulator now. I'm optimistic the B1 boards (being made now in Taipei) will be clean.

It will be great when we've got lesson plans written up so kids can learn how to control the bot with Turtle ( Read more... )

Here's a quick look at the next versions of the XOrduino and XO Stick boards. These were assembled from a small quantity of "pre-B1" boards I had made at BatchPCB.

I've uploaded some more pictures to the XOrduino album as well.

Here's a little table relating the board versions pictured with those I've previously discussed.
BuildXOrduinoXO ( Read more... )

Free things first: I've got parts for 20 copies of the "Mk I" XOrduino and XO Stick. I'm mailing them out for free (!) in exchange for your development help. Send me an email at xorduino@gmail.com describing what you'd like to do with the XOrduino/XO Stick, and your full mailing address. Best 20 or so get kits.


( Read more... )

This week I will be at the 2012 Interaction Design and Children conference in Bremen, Germany. I will be presenting the Growing Up With Nell paper as well as discussing the OLPC Foundation's literacy pilots in Ethiopia.

The Literacy Project is a collaboration between four different groups (as ( Read more... )

I banged out two open hardware designs this week, designed for use with the OLPC XO laptops.

The first is the XOrduino, a stripped down low-cost Arduino-compatible board that plugs right into the XO's USB ports. But wait, there's more: it's also compatible with the Scratch Sensor Board, so you can use this device to control Scratch (and Turtle Art ( Read more... )