Professor Shai Simonson

How Computers Work

CSC 195



Logo Reference Sheet

    Here is a list of Logo built in procedures organized by their function.  The help facility in Logo (as well as myself and the TA) can be consulted for details.  Note that this list is a small but sufficient subset of the entire Logo language.


     Turtle Related
     bk     fd     lt     rt     cs     draw     home     setpc     tt     st     ht     setxy     setbg     pu     pd      setpattern     (seth)eading     (setw)idth     stampoval     stamprect     setfont       fill     fs     ss
     Text Related                                                                           Sound Related
     ct     print     read     readlist       key?      readchar              tone     play
     Mouse Related
     button?  mouse

    Environment related:

     edit     bye     erase      define(control-D)

    Debug related: (The traffic light icons)

     pause     continue     trace

    Procedure related:

     to     end     stop     toplevel     wait    local

    List/Data related:

     first     bf     last     bl     se     list     word     make     count

    Control related:

     if     then     else     not     and     or      equal?
     =     >=     >     <     <=     number?     member?     empty?
     word?     list?     repeat      run

    Computation related:

     +     -     *     /     int     remainder     round     ascii     char      random


    A backslash "\" can be used to continue a line on the next line.  Make sure that "\" is the very last thing on your line.  A semicolon ; can be used for comments since anything after a semicolon until the end of the line will be ignored by the Logo interpreter.

    Logo Bugs:  Be careful!

    1.  NOT to use a backslash on any line that has open parenthesis on it.
    2.  NOT to use ; for comments inside any "repeat"
    3.  NOT to use -  in a list for PRINT.

    If you find anything that you believe is a Logo bug (i.e. a problem that is due to an error in the Logo Interpreter Program rather than in your program), please alert me or the TA.