100 COUNT=0
110 INP=PORT1.AND.1
120 IF INP=1 THEN  GOTO 110
130 INP=PORT1.AND.1
140 IF INP=0 THEN  GOTO 130
150 COUNT=COUNT+1 : REM PRINT COUNT
160 IF COUNT=10 THEN  GOTO 200
170 IF COUNT=20 THEN  GOTO 250
180 GOTO 110
200 REM Output low
210 PORT1=253 :  REM P1.1 = 0
220 GOTO 110
250 REM Output high
260 PORT1=255 :  REM P1.1 = 1
270 COUNT=0
280 GOTO 110