Definition: Logo

A high-level programming language noted for its ease of use and graphics capabilities. It is a recursive language that contains many list processing functions that are in LISP, although Logo's syntax is more understandable for novices.

Stemming from a National Science Foundation project, Logo was created by Seymour Papert in the mid-1960s along with colleagues at MIT and members of Bolt Beranek & Newman. Originally developed on large computers, it was later adapted to many personal computers. A wealth of information about Logo and its educational philosophy is available from the Logo Foundation, http://el.media.mit.edu/Logo-foundation.

Command the Turtle
Turtle Graphics is the graphics language built into Logo, which allows complex graphics images to be created with a minimum of coding. The turtle is a triangular-shaped cursor, which is moved on screen with commands that activate the turtle as if you were driving it, for example, go forward 100 units, turn right 45 degrees, turn left 20 degrees.

The following Object Logo example converts Fahrenheit to Celsius:

   convert
   local [fahr]
   print "|Enter Fahrenheit |
   make "fahr ReadWord
   print "|Celsius is |
   print (:fahr - 32) * 5 / 9
   end

The Logo Turtle

Logo's Turtle Graphics provides a simple, intuitive way to learn about and program graphics. The commands cause the triangular cursor (the turtle) to draw the image on screen.