How to convert from base-256 to base-N, where N is greater than 16?

Question

I need to convert an array of bytes to another base, namely 85. In mathematical terms, the question is, how is it most efficient to convert from base-256 to base-85?

This question is inspired by my previous question - What is the most efficient way to encode an arbitrary GUID into readable ASCII (33-127)?

Thanks.

Answer 1

Do you mean this? http://www.codinghorror.com/blog/2005/10/c-implementation-of-ascii85.html