10 PRINT BIN$(50)
100 DEF BIN$(N)
110   LET N=ABS(INT(N)):LET B$=""
120   DO
140     LET B$=STR$(MOD(N,2))&B$:LET N=INT(N/2)
150   LOOP WHILE N>0
160   LET BIN$=B$
170 END DEF