RosettaCodeData/Task/Binary-digits/Maxima/binary-digits.maxima

digits([arg]) := block(
   [n: first(arg), b: if length(arg) > 1 then second(arg) else 10, v: [ ], q],
   if n = 0 then [0] else (
      while n # 0 do (
         [n, q]: divide(n, b),
         v: endcons(q, v)
      ),
      v
   )
)$

binary(n) := simplode(reverse(digits(9000, 2)))$

binary(9000);
"10001100101000"