Petit Computer Journal #21

A Simple Timer

This here is a simplified version of the timer program. I put it here just to clarify that there are other ways to do this. The previous version was used to show LOOP construct, but this version is an optimized version of it. Notice that duplicate codes are collapsed into one, thus simplifying the whole structure.

1. 'TIMER PROGRAM BY HARRY HARDJONO
2. SPSET 1,156,0,0,0,0
3. SPOFS 1,-50,-50
4. SPANIM 1,4,15
5. SPSCALE 1,200
6. 
   
7. @INIT
8. CLS
9. SPOFS 1,0,96,0
10. SPREAD(1),X,Y
11. ?"HOW MANY SECONDS?"
12. INPUT T
13. IF 0>=T GOTO @END
14. CLS
15. ?"A STARTS TIMER"
16. ?"B SETS NEW TIME"
17. ?"X EXIT"
18. ?"Y PAUSE"
19. 
    
20. @LOOP
21. VSYNC 1:B=BTRIG()
22. IF (SPCHK(1) AND 1) THEN SPOFS 1,X,Y,0 
23. IF (B AND 16) THEN SPOFS 1,224,96,FLOOR((224-X)*T/224)*60:GOTO @TICK
24. IF (B AND 32) GOTO @INIT
25. IF (B AND 64) GOTO @END
26. GOTO @LOOP
27. @TICK
28. IF (BUTTON(0) AND 128) GOTO @LOOP
29. LOCATE 0,8:SPREAD(1),X,Y:?"TIME LEFT: ";FLOOR((224-X)*T/224);"   "
30. IF (SPCHK(1) AND 1) THEN BEEP 28:WAIT 60:GOTO @TICK
31. ?"TIME'S UP!":SPOFS 1,0,96,0:X=0:BEEP 50:WAIT 120
32. GOTO @LOOP
33. 
    
34. @END
35. ?"GOODBYE!"
36. SPCLR 1:WAIT 300