Sharp MZ-800 - Page 56

10 INIT “CRT:M1”
20 A=STICK(0):B =STRIG(O)
30 ON A GOSUB 200,300,400,500,600,700,800,900
40 IF X<0O THEN X=0
50 IF X>319 THEN X=319
60 IF Y<O THEN Y=0
70 IF Y>199 THEN Y=199
80 SET X,Y
90 IF B=1 GOTO 10
100 GOTO 20
200 Y =Y — 1:RETURN
300 X=X+1:Y=Y—1:RETURN
400 X=X + 1:RETURN
500 X=X+1:Y=Y +1:RETURN
600 Y =Y + 1:RETURN
700 X=X—1:Y =Y¥ + T:RETURN
800 X =X — 1:RETURN
900 X =X —1:Y =Y— 1:RETURN