10 READ N
20 IF N < 0 THEN 70
30 GOSUB 100
40 PRINT N"-> "B$
50 GOTO 10
60 DATA 5, 50, 9000, -1
70 END
90 REM *** SUBROUTINE: CONVERT INTEGER IN N TO BINARY STRING B$
100 B$=""
110 FOR N1 = ABS(INT(N)) TO 0 STEP 0
120 :  B$ = MID$(STR$(N1 AND 1),2) + B$
130 :  N1 = INT(N1/2)
140 NEXT N1
150 RETURN