LOGO-L> solving out-of-space problem in whole-class project

[wap3@cornell.edu (Wendy Petti)]

Back in April, there was a bit of discussion of how to deal with space
problems when compiling a whole-class MicroWorlds project in which each
student contributes one drawing.  I didn't put my two cents in at the time
because I was too busy compiling my own whole-class MicroWorlds projects to
read my e-mail!  However, I do have a simple solution for anyone who
encounters this type of trouble in the future.  I will use the original
sender's problem as the sample project here.  Each student had drawn a book
poster directly into MicroWorlds.  From here on, this message quotes
directly from my reply to Peter Cassidy, the original sender:

"I used an approach which actually was recommended by one of the people
trying to help you, although he didn't explain it clearly.  The idea is to
create a FOLDER for your project.  You keep each page independently in the
folder as a PICT file. You also keep your compilation project in that
folder. To create the proper sort of PICT file, and it's not too late to do
it for the pages in your current compiled project, you type in the command
center, SAVEPICT "name.of.page  and hit return.  You won't see anything
happen, but when you quit MicroWorlds, you will see a PICT file by that
name located in whatever folder that project was in when you typed the
command.  If you were just inside the general MicroWorlds 2.0 folder, then
that's where the PICT file will be.  However, for simplicity's sake, you
should create a folder called "Book Illustrations" or whatever, and place
the compilation project inside it, before you start doing all the SAVEPICT
commands.  You can name them according to the student's project name or
simply assign them each a number, as in SAVEPICT "book.1  SAVEPICT "book.2
etc.

        (By the way, when collecting these PICT files from a number of
different student machines, you simply copy the individual PICT files onto
a disk, not needing to copy a MicroWorlds page or project at all, and then
copy them from the disk onto the main computer for the compilation project.
Obviously, with a network, you can bypass the disk altogether.  But again,
it's essential that they all end up in the same folder, along with the
compilation project!)

        Now you can delete every single page in your compilation project,
except page 1!  Type RECYCLE to free up the now-available space.  Of
course, your project will look practically empty, but don't worry.  You
just need LOADPICT commands to load each picture at the appropriate time.

        When our class did a similar compilation, using pictures of maps
the children had drawn, we set up a textbox which we eventually made
invisible.  Each line of the textbox in your case would look like this:
LOADPICT "book.1
LOADPICT "book.2
LOADPICT "book.3
and so on.

        Your page 1 of buttons can still bring you to each picture, but the
instruction needs to be changed so that instead of sending you to a
different page of the project, it does the related LOADPICT instruction
instead.  [Actually, so that all the buttons don't block the drawing, you
would probably want a page2 for displaying the loaded PICT files, with just
one button to return you to page1.] The reason for the invisible textbox is
to create the slide show.  The easiest method is to make a random slide
show.  Create a button called "load.a.book" or whatever.  Write a procedure
by the same name.  The instruction is only a few words:

to load.a.book
run textpick "text1
end

(where text1 is the name of the invisible textbox holding all the LOADPICT
commands.)  [Textpick picks a line at random from the textbox.]

Writing a procedure to show each picture in a certain order can be done one
of two ways:

1)      to slide.show
        loadpict "book.1 wait 50
        loadpict "book.2 wait 50
        etc...
        end

2)      to slide.show.reset
        make "slide.number 0
        end

        to slide.show
        run textitem :slide.number + 1 "text1
        wait 50
        slide.show
        end

In the second version, slide.show obviously is a recursive procedure which
will keep on running until you click the slide.show button again.  It will
begin by running the first line of the invisible textbox (named text1) -
which means it will load the first book picture, and after waiting 50 (or
whatever interval you choose) will then proceed to line 2 of the textbox,
and so on.

        You can write a startup procedure so that the slide show will
always start with the first book poster:

to startup
slide.show.reset
end

or create a reset button to do the same thing.

        I am not experienced with networks, but I do want to say that 475's
are marginal machines for running MicroWorlds, even with the upgraded hard
drive capacity and RAM.  The processor is pretty slow.  Your project size
was getting really huge for even much more powerful machines.  The method
I've suggested gives you a very tiny project size, and it should run fine
on all your machines.  However, you do need to be sure to copy the entire
folder to each machine [or make it available to each machine through the
network], and you need to be sure that the compilation project is located
in the same folder as the PICT files.  If you want your project icon to be
easier to find, you can keep an alias of it outside of the folder in
whatever place you choose, even the desktop.

Wendy A. Petti
Lower School computer teacher
Washington International School
Washington, D.C.
wap3@cornell.edu


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