Scheme UK Meeting

On July 28, 2004

The next Schematics (Scheme User Group) meeting at LShift offices will be on Wednesday Aug 11th at 7pm. Christian Jacobsen and Matt Jadud will talk on ‘Bring out yer dead! A Transputer Interpreter in Two Acts’. Everyone is welcome, but do let us know you are coming.

ACT I. Scheme: Occam is a small (dead?) language based on an the Concurrent Sequential Processes algebra[1]. Scheme is a small (not so dead?) language based on the lambda calculus[2]. However, Scheme is the All Language, descended from the Mighty LISP, blessed by Guy Steele. What better language to write an interpreter of Transputer bytecode (the compiled form of occam programs) than Scheme?

ACT II. C: Unfortunately, while semantically clear, a Scheme interpreter runneth not on the LEGO Mindstorms. So, the Scheme interpreter was rewritten, largely line-for-line, in C, and it became many times faster and many times smaller. What we ended up with is a small, portable runtime for occam programs, that currently runs on
Linux/x86, Linux/MIPS, Windows, Mac OSX, and the LEGO Mindstorms[3].

This play will present a bit of background on occam (for those who are unfamiliar), the interpreter itself, and most importantly, some bits about why we think it is a good thing that we can now run occam on the LEGO
Mindstorms. If FedEx is willing, little robots will be present.

(For those following along at home, the first paper found at reference number three is probably the most interesting for you to glance at, if you wish, before the talk.)

  1. Oh, please. You guys know where to find Scheme stuff on the WWW
  2. The Transterpreter: a Transputer interpreter
  3. Although not mentioned previously, you may also be interested in the Little Languages for Little Robots paper; it is, in some backwards way, related.