title: Base91, how is it calculated?
body: <p>I've been looking online to find out how basE91 is calculated. I have found resources such as <a href="http://base91.sourceforge.net/" rel="noreferrer">this one</a> which specifies the characters used for a specific value but nowhere have I found how I get that value.</p>
  
  <p>I have tried changing the input values into binary and taking chunks of both 6 and 7 bits but these do not work and I get the incorrect output. I do not want code that will do this for me as I which to write that myself, I only want to know the process needed to encode a string into basE91.</p>