williams-et-al-1983-apple-ii-computer-graphics

78 APPLE II COMPUTER GRAPHICSThe following program will POKE into memory the values we justgenerated. We will plot the cannon in the upper left corner of thescreen.10 REM POKE CANNON20 REM THE HARD WAY !30 REM40 HGR50 REM QUADRANT A60 POKE 8192,85 : POKE 9216,85:POKE 10240 ,85: POKE 11264,8570 POKE 12288, 0 : POKE 13312,32 :POKE 14336,48: POKE 15360 ,12080 REM QUADRANT B90 POKE 8193,42: POKE 9217,106:POKE 10241,106: POKE 11265,42100 POKE 12289,20 : POKE 13313,21:POKE 14337,53: POKE 15361,120110 REM QUADRANT C120 POKE 8320 ,120 : POKE 9344,48130 REM QUADRANT D140 POKE 8321,120 : POKE 9345,48150 ENDListing 8-3. Cannon poker.Listing 8-3 makes no pretense at cleverness, but it does perform aspromised .By now you have seen how the individual bits on the Hi-Res screen arecontrotled, and how you can wade through the memory map to fi nd thebyte of your dreams. Using those ideas, you have developed the data forand plotted some simple figures on the screen. Not bad fo r a day's work,eh?VocabularyColumn AddressDigitizingPosition AddressRow AddressExercises1. Place the given dot pattern where indicated on the Hi-Res screen.a. -XX -X -X in row 10, column 20 of boxes, and fi rst byte of the box.