Re: LOGO-L> STOP and STOPME

[Yehuda Katz <yehuka@beitberl.beitberl.ac.il>]

Hello Bill and thank you for your fast reply.

KERRB@Magill.UniSA.edu.au wrote:
> 
> Yehuda wrote in reply to Augusto:-
> 
> >I know absolutely nothing about MicroWorlds, so sorry for asking what
> >might be trivial for you:
> 
> >I don't understand what you mean by "process". Do you mean "procedure"?
> 
> I suppose the new word "process" comes from the fact that MicroWorlds does
> emulate parallel processing. MicroWorlds launches independent processes. eg.
> click on a button to make a song play, then on a turtle to make a bird fly.



Playing music is done apparently by a seperate processor. But I still
can't see how MW can process two programs (except music) paralelly.



> >You say that MW runs paralelly several "processes". How is it that done
> >on a single-processor computer?
> 
> I don't know the technical details of how it is done but I think its a major
> improvement. Its more like real life. We walk down the street and hum a song at
> the same time in real life, naturally without thinking about it. MicroWorlds
> allows us to emulate that on the computer.
> 
> >Do you think that in MW, STOPME is an essential command and normally one
> >can't do without it?
> 
> Here is a simple case that arose from the work of a year 9 student the other
> day. He had a bird flying and the man walking simultaneously. He wanted the
> man to stop when he reached a tree and the bird to keep on flying. He
> programmed the colour brown (tree trunk) with stopme and made sure the bird
> didn't fly through any brown. It was useful and easier than other ways.


If so, THROW "TOPLEVEL is not the same as STOPME, as THROW "TOPLEVEL
stops ANY action of Logo, puts it in toplevel, as its name implies, and
returns the command to the user at the keyboard.

But I still wonder: What would happen in your above program had you used
STOP instead of STOPME?

Thank you,

[[Yehuda]]


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