[etoys-dev] Toy computers

[David T. Lewis]

Thanks to all for the suggestions and Etoys tips. I'm looking forward to
finding a few more free weekends to play around with these ideas. A few
comments below:

On Sun, Oct 02, 2011 at 09:13:08PM -0700, Casey Ransberger wrote:
>
> Have you looked at Chuck Thacker's Tiny Computer? It's in Points of View,
> that book they did for Alan's birthday.
>
On Mon, Oct 03, 2011 at 09:16:24PM +0100, David Corking wrote:
>
> Have you a target processor in mind?  Last year, a friend lent me a
> copy of Donald Knuth's 'Art of Computer Programming' Vol. 1, and ever
> since then I have thought that a model of the MIX computer would be an
> interesting Etoy. However I think there are simpler learning computers
> that could be modelled, though I don't know their names let alone
> their specifications.

Both good ideas, although perhaps a bit ambitious for children to get
started with. I can't help but mention also that Squeak itself has a good
target machine: the Squeak VM. It has a byte coded instruction set and
it comes with an interpreter written in Squeak. The Smalltalk implementation
(which is called the "interpreter simulator" and which nowadays is kept
in the VMMaker package on SqueakSource) is a complete working virtual
machine, and if you changed it around a bit to use Etoys registers rather
than "cheating" and using integers, then it might well become a working
"visual Squeak VM". Of course it would not be very fast, but that's not
the point ;)

On Mon, Oct 03, 2011 at 09:16:24PM +0100, David Corking wrote:
>
> I guess one approach could be to encourage a learner to experiment
> with different architectures.

I like this idea the best, especially if it encourages learners to
try things like "what is the simplest machine I can make that can
add 2 plus 2?" and "how wide do my registers be if I want to multiply
3 times 5?" and "what happens to the result if my register is not
big enough?".

On Tue, Oct 04, 2011 at 08:46:19AM +0200, Markus G??lli wrote:
> And you might want to use connectors as exemplified in
>  http://scg.unibe.ch/download/petitpetri/
> a petri net editor built with Etoys.

That's a great idea, Connectors would be just right for wiring together
the data paths.

Dave