Lecture 7
21
Counting 
•1,2,3,... (everyday, mathematics)
•0,1,2,... (computer science)
•Screen models (x,y) coordinates
–y value increases as you read down
–(0,0) is upper left hand corner
–Each location holds one pixel – a character
–Frame of +’s is not part of Screen
•5 ´ 3 Screen with                                                         G at position (3,1),                     & at position (0,2)
•       
     0 1 2 3 4 
  + + + + + + +
0 +           +
1 +       G   +
2 + &         +
  + + + + + + +