Here's a great project for budding Babbage's or anyone handy with a bit of number 8 fencing wire; build your own computer - or bits thereof - and then, via the magic of the internet, get it running. The end result is called a Heath Robinson/Rube Goldberg (HRRG) computer.

The basic idea is outlined in a paper by Clive Maxfield with the suitably snooze-inducing title Implementing a computer using a mixture of technologies from relays to fluidic logic. Don't be put off, it's a brilliant idea. Here's how it works:

1. Download the emulator and run a virtual HRRG machine on your PC.
2. Pick the physical component you want to build and make it.
3. Connect this component via USB, switch out the emulated component out and run with the physical one. You're now running a mix of virtual plus physical componentry.
4. Using the internet, connect in other peoples' components to complete your computer.

To get you started Maxfield has a few suggestions. How about making the system clock from that old horror movie prop the spark-arcing Jacob's Ladder?



Add a photo-detector and you could count the sparks as ticks. Or how about pneumatic ping-pong ball memory?



The possibilities are endless - and educational.

(There's no need to go to this extent. This guy built an entire computer out of relays!)



[All illustrations are from Maxfield's paper.]