Logo Programming

But quite surprisingly, when later during my Ph.D. part of my time was dedicated to give exercises to students. And we used logo instead of the more usual programming languages. And I think it really helped them to really internalise programming a lot better. Typically, the latest exercices introduced recursion which is immediately visible as fractals.

    HIDETURTLE
    
    PENUP
    SETXY -200 0
    RIGHT 90
    PENDOWN
    
    to dragon :degree :size
        setpensize 1
        if :size>5  [setpensize 2]
        if :size>10 [setpensize 3]
        if :size>20 [setpensize 4]
        if :size>40 [setpensize 5]
        ifelse :degree=0 [
            fd :size
        ][
            left  45 dragon (:degree-1) (size/4)
            right 90 dragon (:degree-1) (size/2)
            left  90 dragon (:degree-1) (size/4)
            right 45
        ]
    end
    
    dragon 6 3000

[0] https://www.gentleknowledge.com/

[1] https://en.wikipedia.org/wiki/Math_circle

[2] https://www.amazon.com/dp/0817641610

When I realized that all of logo was actually saved on that disk and I could continue playing with the turtle at home, I was amazed.

Drawing little things, realizing that I was repeating stuff and breaking it into little functions so I could draw them again more easily. I was learning the essentials of programming and didn't even realize it.

My first ever english word that I can spell out is REPEAT.

Do yourself a favor, and read it today : it is that good. Even though it is quite depressing to see that the revolution in education that the book was predicting in its preface, simply never happened.

We had "no screen in the morning" house rule - we had to eat, play outside first while it was not too hot. I woke up and realised what was wrong with my code. And my mum made an exception to the rule and the fix worked! I am so grateful to her for understanding the importance of the moment and allowing me to do the fix. I guess I'll give her a call and tell her the story now :) Thanks HackerNews!

and Music Blocks

https://musicblocks.sugarlabs.org/

LOGO variants by Walter Bender (also student of Seymour Papert) https://en.wikipedia.org/wiki/Walter_Bender

https://apps.kde.org/nl/kturtle/ (in pretty much every linux distro) also brings that benefit (though the language is not exactly a LOGO clone).

Early 80's I learned Logo and Basic at a local store that sold Apple computers. It was called "The Logical Choice" and had a classroom tucked away behind a false wall and an English Sheep dog "Sir Isaac Newton" that would hang around the store!

Nice, I just found a story on the store, page 5 of [1].

[1] https://mirrors.apple2.org.za/ftp.apple.asimov.net/documenta...

What I find interesting it that it's not just programming, specifically. Logo is a highly interactive and dynamic language (a relative of Lisp), and that influenced the way I think about writing code. Seymour Papert did a lot for me, albeit highly indirectly.

https://mschaef.com/c64

[0] https://www.macintoshrepository.org/6717-logo-writer-2-0

[1] technically I had used the Apple II version a couple times first

[2] https://applerescueofdenver.com/products-page/macintosh-to-p...

For many of us, it was our first encounter with programming.

So, draw a curve from the ground to the sky. Draw some explosion shape. Change pen color to the sky color. Draw the curve and the explosion again to erase them. Change pen color and start the next firework.

It was like a little futuristic tank. I searched for a minute, and I cannot find the exact model. Did I imagine this?

It's been all downhill since.

During the second Logo class, the teacher set up a competition. A prize was to be given to the student who could first plot an equilateral triangle, a square, a regular pentagon, a regular hexagon, etc, up to a regular icosagon. I won the prize because I wrote formulas to make the computer do the angle computation. I was so so proud of myself compared to my classmates who were computing angles with pen and paper. It felt like the first inkling of the power of automation.

Logo was just perfect for thinking in Agents

70 comments here and they're basically all positive about Logo being formative

https://turtlespaces.org

The computer is running windows 95. The teacher starts Logo and I see that turtle in the middle of the screen. She explains how to make it move.

And I start typing my very first code.

It’s lisp based. Took me 28 years to learn that. Now I think I need to finish the job and pock up lisp.

310 versions!! https://pavel.it.fmi.uni-sofia.bg/logotree/pdf/LogoTree.pdf

Also, The Great Logo Adventure is a great book for kids learning Logo. It's what I learned with, and it's available as a free PDF now!

Came for the graphics, stayed for the recursion and string handling

After a while I was running laps around my teachers and I knew computers were for me.

The whole point was a very visual way of learning with immediate feedback, where you build stuff in order to understand it.

Papert based his own ideas of constructionism on children's cognitive development theories of Jean Piaget, a famous Swiss psychologist with whom he worked in the 50s - early 60s.

Logo pioneered a whole class of tools and languages built around constructivist ideas (e.g. Ozobot, Scratch, EToy, Processing, Design by Numbers...) and I hope these ideas will not be totally forgotten in the era of slop, when people prize ignorance and no longer seem to appreciate the concept of "build to understand".

https://escholarship.org/uc/item/1623m1p3

https://news.ycombinator.com/item?id=36755727

larsbrinkhoff on July 17, 2023 [–]

A list of all Logo memos, with links where I could find them.

https://github.com/pdp11/sits/wiki/List-of-Logo-memos

https://news.ycombinator.com/item?id=28605037

larsbrinkhoff on Sept 21, 2021 | next [–]

Your LLOGO copy was for an older version of Maclisp, but eventually we (Eric and I) managed to port it over to New IO. It works fine and displays on an emulated Knight TV. (Itself a tour de force in emulation: the TV PDP-11 code runs on an emulator sharing its Unibus with the PDP-10 emulator.)

We also have an early PDP-11 Logo, an even earlier BBN PDP-10 Logo, and a later Apple II Logo (not the Terrapin version). I also wrote an emulator for the General Turtle 2500 computer slash terminal.

DonHopkins on Sept 21, 2021 | parent | next [–]

Do you have the specs for the infamous military Terrapin Snapping Turtle proposed to the Department of Defense?

https://dl.acm.org/doi/10.1145/1056602.1056608

https://donhopkins.com/home/TurtlesAndDefense.pdf

>TURTLES AND DEFENSE

>Introduction

>At Terrapin, we feel that our two main products, the Terrapin Turtle ®, and the Terrapin Logo Language for the Apple II, bring together the fields of robotics and AI to provide hours of entertainment for the whole family. We are sure that an enlightened application of our products can uniquely impact the electronic battlefield of the future. [...]

>Guidance

>The Terrapin Turtle ®, like many missile systems in use today, is wire-guided. It has the wire-guided missile's robustness with respect to ECM, and, unlike beam-riding missiles, or most active-homing systems, it has no radar signature to invite enemy missiles to home in on it or its launch platform. However, the Turtle does not suffer from that bugaboo of wire-guided missiles, i.e., the lack of a fire-and-forget capability.

>Often ground troops are reluctant to use wire-guided antitank weapons because of the need for line-of-sight contact with the target until interception is accomplished. The Turtle requires no such human guidance; once the computer controlling it has been programmed, the Turtle performs its mission without the need of human intervention. Ground troops are left free to scramble for cover. [...]

>Because the Terrapin Turtle ® is computer-controlled, military data processing technicians can write arbitrarily baroque programs that will cause it to do pretty much unpredictable things. Even if an enemy had access to the programs that guided a Turtle Task Team ® , it is quite likely that they would find them impossible to understand, especially if they were written in ADA. In addition, with judicious use of the Turtle's touch sensors, one could, theoretically, program a large group of turtles to simulate Brownian motion. The enemy would hardly attempt to predict the paths of some 10,000 turtles bumping into each other more or less randomly on their way to performing their mission. Furthermore, we believe that the spectacle would have a demoralizing effect on enemy ground troops. [...]

>Munitions

>The Terrapin Turtle ® does not currently incorporate any munitions, but even civilian versions have a downward-defense capability. The Turtle can be programmed to attempt to run over enemy forces on recognizing them, and by raising and lowering its pen at about 10 cycles per second, puncture them to death.

>Turtles can easily be programmed to push objects in a preferred direction. Given this capability, one can easily envision a Turtle discreetly nudging a hand grenade into an enemy camp, and then accelerating quickly away. With the development of ever smaller fission devices, it does not seem unlikely that the Turtle could be used for delivery of tactical nuclear weapons. [...]

https://medium.com/@donhopkins/logo-adventure-for-c64-terrap...

>When I was 17, Terrapin published my first commercial code on their C64 Logo utilities disk: a Logo Adventure program, a simple non-graphical game that showed off Logo’s list processing and functional programming capabilities. [...]

https://news.ycombinator.com/item?id=23054174

Here is the source code to LLogo in MACLISP, which I stashed from the MIT-AI ITS system. It's a fascinating historical document, 12,480 lines of beautiful practical lisp code, defining where the rubber meets the road, with drivers for hardware like pots, plotters, robotic turtles, TV turtles, graphical displays, XGP laser printers, music devices, and lots of other interesting code and comments.

https://donhopkins.com/home/archive/lisp/llogo.lisp

Lars Brinkhoff got some of this code to run in MacLisp on an emulator! (I don't know how much of the historical hardware the emulator supports yet, but he's probably worked on some of that too. ;) )

https://github.com/PDP-10/its/issues/620

Thanks to Lars, here are two revisions of an AI Lab memo about LLOGO:

http://bitsavers.org/pdf/mit/ai/aim/AIM-307.pdf

http://bitsavers.org/pdf/mit/ai/aim/AIM-307a.pdf

And a Logo manual and glossary of PDP-11 Logo:

http://bitsavers.org/pdf/mit/ai/aim/AIM-313.pdf

http://bitsavers.org/pdf/mit/ai/aim/AIM-315.pdf

http://bitsavers.org/pdf/mit/ai/aim/AIM-315a.pdf

There's a whole Lispy beauty behind the language that teachers didn't know how to transmit to the kids because they themselves didn't understand it. The emphasis on turtle graphics was limiting.

TThe only reason we got to learn it at all was because one of the daycare workers was a graduate student at the University of Washington. She somehow got permission for any of the kids who were interested to use the school's computer lab. Which, I think, took some doing on her part.

Back then, computers were treated like sacred objects. They made a huge deal about kids using them. The whole first week of the class was basically some grumpy old guy with a white beard telling us, "These are not toys! These are expensive machines!"

We had to wash our hands before we were allowed into the computer room. The old guy would literally "hand check" us at the door. You had to hold out your hands and show him that they were clean before you were allowed anywhere near the computers.

Logo was a lot of fun. We had a competition to see who could draw the coolest thing. Just like foundation for a "hackathon" really. Every day, "OK, Kids, you have 30 minutes, let's see what you can do!" Was a lot of fun.

I had to ask my mom for a floppy disk. "Mom, I need $5 for class supplies..." And then I had to explain that it was for a computer disk... and she had to call the school to make sure I was getting the right thing... even though I told her 100 times that I needed an un-formatted 5.25" disk! Ha.

Anyway good memories here. Logo and HyperCard were gateway drugs.

https://www.netlogo.org/

https://snook.ca/technical/colour_contrast/colour.html#fg=96...