Recognize the computer

Author: Zhu Hua
Publisher:
Publish Date: 1999-10-01
Features: Brief Introduction:
1. Sea turtle centered, ready to draw
2. Move forward and backward to adjust direction
3. Lift and lower the pen, sea turtle returns home
4. Multiple corners repeat commands at turns
5. Simply draw a circle, approximate with multiple sides
6. Precisely draw a circle with radius control, etc.