                       V      VVV   VVV   VVV
                       V     V   V V   V V   V
                       V     V   V V     V   V
                       V     V   V V VVV V   V
                       V     V   V V   V V   V
                       V     V   V V   V V   V
                       VVVVV  VVV   VVV   VVV

                           <By Evan Hoke>
Description:
Logo is a programming language similar to LISP for drawing designs 
by controlling a turtle (triangle), which traces its path on the screen.  
This implementation of Logo supports 12 different commands as well 
as different Zoom options.

Requirements:
A TI-83 Plus Calculator
A graph link or equivalent, for sending the program to your calculator.

Installation:
Simply send "Logo.8xk" to your calculator using the software that 
came with your graph link.

Using the Program:
Run the program from the application menu.  Upon running the 
program press any key when the splash screen appears.  You can now 
type commands. Press "ALPHA" to switch between letter and number 
mode. Use the left and right arrows to move the flashing cursor. Press 
"DEL" to delete a character. Press "CLEAR" to clear the line. The () 
keys will type [].  Press "ZOOM" to change the window.  Press "Y=" at 
any time for help. Press "MODE" to quit.  The turtle starts at (0,0) 
pointing up.  The program is affected by the current graph mode and 
whether the calculator is in radians or degrees mode.

Basic Commands:
FD X
moves turtle forward X steps
BK X
moves turtle backward X steps
LT X
turns turtle X degrees or radians counterclockwise
RT X
turns turtle X degrees or radians clockwise
PU
turns off drawing of turtle's trail
PD
turns on drawing of turtle's trail
HT
hides turtle
ST
shows turtle
CLR
clears the screen
HOME
brings turtle to (0,0) pointing up, line drawn from previous spot if pen 
is down
CLRHOME
clears screen and brings turtle to (0,0)
REPEAT X [commands]
repeats commands in brackets X times

Zoom Menu:
Press Zoom to access the zoom menu.  Press Clear or Mode to exit the 
zoom menu. The functions in the zoom menu are similar to when the 
calculator is in standard mode. Zoom fit will fit the entire drawing in 
the screen. Drawings often look best in Zoom Square.

Neat Designs:
Zoom Standard then Zoom Square for best viewing. Use degree mode.
Square: REPEAT 4 [FD 8 LT 90]
Pentagon: REPEAT 5 [FD 7 LT 72]
Hexagon: REPEAT 6 [FD 6 LT 60]
Fake Circle: REPEAT 360 [FD .1 LT 1]
5pt Star: REPEAT 5 [FD 8 LT 144]
9pt Star: REPEAT 9 [FD 8 LT 80]
Rotating Squares: REPEAT 12 [REPEAT 4 [FD 7 LT 90] LT 30]
Try your own! The possibilities are endless.

Bug Reports, Questions or Comments?
If you would like to report a bug or have a question or comment about 
Logo, please email me at ehgid@attbi.com.  Please be very descriptive 
in a bug report so that I can identify the problem and fix it.

Disclaimer:
I am not responsible for any damage that Logo may cause to your 
calculator or computer.  I have tested the program extensively so there 
should not be any bugs but in the event of a bug, I am not responsible.  
You should always back up your calculator before running assembly 
programs.  Feel free to distribute Logo as long as you keep all the files 
in this folder intact.  Dont get the wrong impression, I am not a stingy 
capitalist (this program is free) but just in case your calculator blows up 
and Russia declares nuclear war, I can say that I am not responsible.

History:
Version 1.0 8/20/02 Released the first version for the soul purpose of 
competing in the TI APP contest.  The program was made in a mere 
two weeks.

Acknowledgments:
I would like to thank the following people for their contribution to 
Logo:

-Speech Technology Incorporated for their great TASM z80 assembler.
-Texas Instruments for making the calculators and releasing a key to 
sign Apps and for their great APP contest which motivated me to write 
this program.
-James Matthews for his great assembly tutorials.
-My family for giving me time to program while we were on vacation.
-MIT and the other institutions that developed Logo
-Wayland Public School system for teaching Logo at an early age, 
which ultimately got me interested in programming.
-You for downloading Logo and taking the time to read this boring file.
-All the people who encouraged me and gave me suggestions on 
making Logo.
-Anybody else that I neglected to mention but helped me along the 
way.
