These programs rely on Logo's turtle interface, which is a convenient and intuitive way to describe graphics imperatively. It's great for kids. These days, Python also has a turtle library (edit: built-in! part of the standard library, for some reason), heavily inspired by Logo, which means that the code on this page can be easily translated into Python. Here are some example that you can run at home (since I assume more people have access to Python these days than likely have a Logo interpreter installed). Edit: these are Python translations (by me) of the top three entries on the linked page.
import turtle
import math
turtle.tracer(0,0) # remove this line to watch the drawing
def spirals():
# repeat 1800 [fd 10 rt repcount + .1]
for repcount in range(1800):
turtle.fd(10)
turtle.rt(repcount+.1)
turtle.update()
def snowflakes(variant=6):
# repeat 8 [rt 45 repeat 6 [repeat 90 [fd 2 rt 2] rt 90]]
for _ in range(8):
turtle.right(45)
for _ in range(variant):
for _ in range(90):
turtle.forward(2)
turtle.right(2)
turtle.right(90)
turtle.update()
def orb():
# for [i 0 420] [seth :i repeat :i [fd 2 rt 1] pu home pd]
for i in range(0,420):
turtle.seth(i)
for _ in range(i):
turtle.forward(2)
turtle.right(1)
turtle.penup()
turtle.home()
turtle.pendown()
turtle.update()
I'm a Python newbie, running on macOS 10.13 with Python 2.7.10. When I save the above as turtle.py, and run with `python turtle.py` in the Terminal, I see an almost instantaneous flash of a tiny window, which then disappears.
When I remove the tracer line to "watch the drawing," I don't even get that. The Terminal just returns instantly.
Looking at tracer documentation, it's supposed to be `(which-frames-to-render, delay)`. If I set it to `turtle.tracer(1, 10000)` I get exactly the same flashing window as (0,0).
Logo was my first programming experience - my older sister(who had Logo in school) introduced me to a few basic commands.
These quickly turned out to be insufficient, so I reverse-engineered the examples shipped with the platform. We didn't have internet access, so that was the only viable option.
When that turned out to be insufficient I noticed that many Logo commands were three characters long and highlighted, so I generated all the three-character combinations and checked them out one by one.
Turns out you can make games in Logo, but sounds and keyboard interactions introduce pauses in the main loop.
Eventually this new browser named Internet Explorer 6, which shipped with a language called JScript, proved to be more interesting, even though I didn't understand what a "<div>" was and how to write a for loop properly.
While this challenge does show off the complexity and beauty of Logo's "turtle graphics", it has often struck me as a tragedy of the language that, for most people who have encountered Logo, they are led to believe that graphics is all it can do (or its only purpose).
Indeed. I've recently discovered NetLogo, which is a variant designed for making simulations, and it is amazing how you can get a sophisticated simulation in about a page of code.
>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.
As a result of a recent thread[1] on HN regarding Logo, we now have a Slack workspace[2] and Freenode IRC channel[3] for Logo fans. Please do join them even if you don't remember Logo anymore. The intention here is not to discuss Logo but to share the joy of computing that we discovered through Logo and has remained in our lives.
> Algorithmic information theory principally studies measures of irreducible information content of strings (or other data structures). Because most mathematical objects can be described in terms of strings, or as the limit of a sequence of strings, it can be used to study a wide variety of mathematical objects, including integers.
Even simple thing like drawing the Euler spiral has much more effect, if you visualize the turtle motion, so you can see how the motion turns at some point and the turtle starts going back on the same way down.
My boss at Logo Computer Systems, Brian Silverman, produced a custom version of Logo with Life Game instructions included (implemented in 6502 asm for //e). This was never marketed.
What was it like? I see on his Wikipedia page that he's made a lot of discrete cellular automata over the years, but Logo seems more...analog and continuous?
It was basically a specialised version of Apple Logo // (which we produced) adding primitives for constructing cellular automata. You would basically define rules, which would be executed and displayed. It was very fast as the execution engine was written in 6502 asm.
