Category: Link

SD Cards on the XO

Here is the page on the OLPC website that documents secure digital cards on the XO.
The XO supports SDHC (high capacity). I use a 16GB AData card on my XO without problem.
Here is a little reminder: when you insert the SD card into the XO, do so with the screen, and the shiny part of the card, both facing you.
BTW: I use a “Sandisk MicroMate for SDHC” USB adapter to work with the card under Windows XP, it cost 8USD from an Amazon affiliate.

erlang-scheme interop

Eric Sessoms announced his Erlang-Scheme interoperability library recently on the PLT discussion list.

What it is: Basically, it’s a port of Distel from emacs lisp over to
scheme. It talks to erlang using its own protocol and impersonates an
erlang node on the network. It aims to provide an abstraction such
that erlang processes look like scheme threads, and vice-versa.
Communication from scheme to erlang is done with (a wrapper around)
thread-send. Messages from erlang to scheme get routed to thread
mailboxes so that they can be picked up with thread-receive.

TeachScheme, ReachJava

A silent revolution has changed the way computer science is understood and taught. The modern curriculum no longer focuses on the constructs of a language and the state changes in the machine. Instead, programming is taught as a problem-solving process that starts from a thorough understanding of classes of data and objects. The TeachScheme! Project has been at the vanguard of this revolution; the new series is its natural extension to cover a seamless transition to object-oriented design using Java.

Teaching is hard, and getting people to change how they teach is even harder. TeachScheme! (read Teach Scheme, NOT!)

wants to turn Computing and Programming into an indispensable part of the liberal arts curriculum.

There are truly world class folks involved in this effort whom I trust. Though I do not yet understand the depth of this project, I find it fascinating, and inspiring.

The 90 Minute Scheme to C compiler

90 minute video presentation from Marc Feeley, along with accompanying PowerPoint slides and source code, for a Scheme to C compiler. Good discussion of continuations and closures, as well as some dipping into the area of compiler construction.

I didn’t work through this but it looks like it might be a fun project to undertake (I’ll add it to the list).
(via LtU)

Advice on writing teachpacks

Here is some advice on writing teachpacks for PLT’s DrScheme.
About teachpacks:

Teaching languages are small subsets of a full programming language. While such restrictions simplify error diagnosis and the construction of tools, they also make it impossible (or at least difficult) to write some interesting programs. To circumvent this restriction, it is possible to import teachpacks into programs written in a teaching language.
In principle, a teachpack is just a library written in the full language, not the teaching subset. Like any other library, it may export values, functions, etc. In contrast to an ordinary library, however, a teachpack must enforce the contracts of the “lowest” teaching language into which it is imported and signal errors in a way with which students are familiar at that level.