I have exciting news. All sorts of things are happening here in the "Pleasure Dome" (my office). As you may recall (you jolly well should, because I've mentioned it often enough), I have a simple 8-bit virtual calculator-computer called the Pedagogical and Phantasmagorical DIY Calculator (http://www.diycalculator.com). The primary interface to this virtual machine is a calculator front panel (http://www.diycalculator.com/imgs/max-vdiy.gif).
This little scamp is used in conjunction with my book "How Computers Do Math" (http://www.amazon.com/exec/obidos/tg/detail/-/0471732788) to teach how computers work in general, and how they can be used to represent, store, and manipulate numbers (do math) in particular. The idea is that the book walks the reader through the process of creating a rudimentary four-function calculator program (written in our simple assembly language).
Well, for the last six months or so, two engineers in Austria have been slaving away designing and building a Physical DIY Calculator (http://diycalculator.pcl.at/index.php). I just heard news that the latest prototype boards have returned and everything works! (Check out a picture of this board here http://www.diycalculator.com/imgs/max-pdiy.jpg).
This is really rather clever. They've used a small FPGA from Lattice Semiconductor to implement our entire microcomputer, including the CPU, ROM, RAM, I/O Ports, etc. This means you can create and test a program in the virtual world on the virtual DIY Calculator, and then download it into the physical DIY Calculator sitting on your desktop. Once the program has been downloaded it is stored in Flash, so you can disconnect the physical DIY Calculator from your PC, power it down, power it up again, and your calculator program will still be there until you overwrite it with a later version.
One reason this is of interest is that the Heath Robinson Rube Goldberg (HRRG) Mixed Technology Computer is based on the same CPU as the DIY Calculator, which means that we'll be able to run our calculator program on "The Beast".
Good grief! There's so much to do, and so little time to do it all in...