We construct a pseudo-random generator for space bounded computations using the extractor of Zuckerman [
7]. For machines that use
S space and
R < 2
1-ε random bits for ε Τ; 0, the generator uses a seed of length O(
(S log
R)/ log
S) which is shorter than the seed of both the generator of Nisan [
4] and the generator of Nisan and Zuckerman[
5]. We then use this generator to derandomize these machines in space

which is better than the derandomization of [
6].