[net.micro.mac] Logo Query: Replies

dubois@uwmacc.UUCP (Paul DuBois) (09/18/85)

A while back, I asked about any experience people had with Logo.
Here's what I got in reply.  My thanks to all who responded, and
I hope it is useful to others as well.
-------------------------------------------------------------------------------
From: uwvax!ihnp4!gargoyle!stuart (Stuart A. Kurtz)
Organization: Dept. of Comp. Sci., The University of Chicago

I have the Microsoft Logo, but not the Expertelligence.  I really like the
Microsoft Logo -- it has an acceptable debugger, and some limited Mac Toolbox
support.  We're giving it some though as an introductory programming language
for our "poets" course.  It seems reasonably fast, and my wife (who has used
Logo extensively on the Apple II's to teach geometry to elementary school
students) thinks its a solid implementation too.

You should know that this is not a Microsoft product in the usual sense --
it was developed by a Canadian software house and Microsoft is just handling
the marketing.  It is *not* copy-protected.  It has a customization program
which enables you to allocate various amounts of space to different types
of objects.  Presumably, if you had a Mega-Mac, you could access the whole
thing...
-------------------------------------------------------------------------------
[I sent back a question to Stuart; this was the reply:]

From: uwvax!ihnp4!gargoyle!stuart (Stuart A. Kurtz)

> Expertelligence Logo has the ability to draw things simultaneously in
> multiple windows.  Does MS Logo do that?

It depends on what you mean.  MS Logo can open lots of "graphics" windows
simultaneously, and can rapidly switch between them -- in essence, maintaining
multiple independent graphics environments.  Like MacPascal, it does not
retain an off-screen bit-image of each window, so if you reveal a portion of
a window that was obsured (say, by another window), it is white.  I consider
this to be a bug, or perhaps an incomplete implementation of what should
really occur.

My current best assessment:  It is a good, solid implementation of Logo that
should be very useful for teaching programming concepts to younger students,
while remaining sufficiently powerful (and *almost* fast enough) for fairly
advanced programming.

>From an advanced point of view, it is a simple Lisp, with fexprs but not
lexprs or macros.  (Although the fact that list arguments are implicitly
quoted enables you to write Logo procedures which implement various control
structures -- which is probably the most important use of macros in Lisp.)
I've found it to be **vastly** superior to MacPSL (Portable Standard Lisp,
Utah) as a lisp programming environment.
-------------------------------------------------------------------------------
From uwvax!ihnp4!ucla-cs!seth Mon Aug 12 01:23:57 1985
Organization: UCLA Computer Science Dept.

I haven't seen MS Logo but I own ExperLogo.  The claims for ExperLogo are
true (i.e. compiled, fast, lots of features) but it is different from Apple
Logo or Krell (Terapin) Logo for the Apple IIs.  In trying to make it a
suitable language for 'REAL' programming, they've gotten away from some of
the simplicity which makes it suitable for children.  In order for a child
to use it, they must be able to manipulate the Mac interface which is no
mean feat for a 4 year-old or younger.  I'm sure plenty of 5-6 year olds
would also have difficulty.

I think it might be confusing for a child to deal with the two different
windows.  Instead of providing a splitscreen, ExperLogo pops up a graphics
window for drawing and the interaction takes place in the Listener window.
This is fine but in order to edit things, you must go into an edit buffer
which is yet another window which will obscure what is already on the screen.

Basically I think it is a good product and could be used by children with
supervision.  I may be misjudging the complexity but being the uncle of a
precocious (obviously a biased opinion) 4 year-old and having watched her
play with my Mac I remain cynical.
-------------------------------------------------------------------------------
From: uwvax!seismo!allegra!alice!dsj
(David S. Johnson, AT&T Bell Laboratories)

I've had microsoft logo for about two months.  My wife tells me that it's
considerably faster than Terrapin Logo on the Apple II (but not so fast that
you can't see the turtle move very well, a complaint I saw on the net some
months ago about Experlogo).  It profits greatly from a 512 Mac, but will
apparently run on a 128.  It has a nice "Mac-ish" interface, in addition
to some advanced features that take advantage of the mac quickdraw routines.
It can do graphics on the sphere.  We liked it very much.

Two drawbacks, however.  One: covering up the graphics window erases
the contents, even if by desk accessory (this is not a bug, as it is
mentioned in the manual, but it is a painful obstacle, given that the Mac
screen is small already, and you need a text window to invoke programs.
Two: You cannot load a file directly into an editor window, as you would
normally want to do when modifying a program.  This IS a bug (microsoft
has been informed and wrote back a nice letter saying they would try to
fix it), but can be circumvented by loading to the text window and then
doing a cut and paste (there is a "select all" on the menu, which speeds
the process).
-------------------------------------------------------------------------------
-- 
                                                                    |
Paul DuBois     {allegra,ihnp4,seismo}!uwvax!uwmacc!dubois        --+--
                                                                    |
"A mind like cement:  thoroughly mixed and permanently set"         |