RCA CDP18S711 manual Some Program Ideas, CHIP-8Language Programming

111. CHIP-8 Language Programming 17

lose the CHIP-8 interpreter and will have to reload it. You can insert stopping points in your program for debugging purposes. Suppose you want to stop and examine variables when your program reaches the instruction at 0260. Just write a 1260 instruction at location 0260. Flip RUN down and use operating system mode A to examine variables V0-VF. The memory map in Appendix C shows where you can find them.

After the above practice you are ready to design more sophisticated CHIP-8 programs. Always prepare a flowchart before actually writing a program. The last 352 bytes of on-card RAM are used for variables and display refresh. In a 2048-byte RAM system you can use locations 0200-069F for your programs. This area is enough for 592 CHIP-8 instructions (1184 bytes). In a 4096-byte RAM system you can use locations 0200-0E8F. This area is equal to 1608-CHIP-8 instructions (3216 bytes).

Some Program Ideas

Here are a few ideas for programs to write using the CHIP-8 language:

1.INTOXICATION TESTER - Display a six digit random number on the screen for several seconds. You must remember this number and enter it from the keyboard within ten seconds after the screen goes blank to prove that you're sober and score.

2.NUMBER BASE QUIZ - Display numbers in binary or octal on the screen. You must enter their decimal equivalent to score points.

3.DICE - Push any key to simulate rolling dice displayed on the screen.

4.PUPPETS - Show large face on the screen. Let small children move mouth and roll eyes by pushing keys.

rBUSY BOX - Let small children push keys to make different object appear on the screen, move, and make sounds.

6.SHUFFLEBOARD - Simulate shuffleboard type games on the screen.

7.COMPUTER ART - Design new programs to generate pleasing geometric moving patterns on the screen.

8.INVISIBLE MAZE - Try to move a spot through an invisible maze. Tones indicate when you bump into a wall.

9.LUNAR LANDING - Program a graphic lunar landing game.

10.COLLIDE - Try to maneuver a spot from one edge of the screen to the other without hitting randomly moving obstacles.

Il. CAPTURE - Try to chase and catch randomly moving spots within a specified time limit.

12.LEARNING EXPERIENCES - Program graphic hand and eye coordination exercises for young children or those with learning disabilities.

13.NUMBER RECOGNITION - Show groups of objects or spots on the screen. Young child must press key representing number of objects shown to score.

WALL BALL - Program a wall-ball-type paddle game for one player.

15.FOOTBALL - Each player enters his play via the hex keyboard and the computer moves the ball on the screen.

16.BLACKJACK - Play "21" against the com puter dealer.

17.HOLIDAY DISPLAYS - Design custom, animated displays for birthdays, Halloween, Christmas, etc.

18.METRIC CONVERSION - Help children learn metric by showing lengths on screen in inches and requiring centimeter equivalent to be entered to score.

19.TURING MACHINE - Simulate a simplifed Turing machine on the screen.

20.TIMER - Use the computer to time chess games, etc.

21.HEXAPAWN - Program Hexapawn so that the computer learns to play a perfect game.

22.NIM - Program Nim with groups of spots shown on the screen.

23.BLOCK PUZZLES - You can simulate a variety of sliding block-type puzzles on the screen.

24.BOMBS AWAY - Show a moving ship at the bottom of the screen. Try to hit the ship by releasing bombs from a moving plane at the top of the screen.