How can you make binary data less filling?
Remove the 1s, of course.
OO O OO O OO OOOO OO OO O O OOO O OOOOO OOO O O OOO OO OO OO O OOO OO OOO OOOO OOO O O O O O OOOO O OO O O O OO OO O OO OOOO O OO OO OO O OO OO O OO OO O OOO O O OOOO OOO OOO O O OO OO O OOOOOO O OOO OO OOO OO OO OO O OO OO O OOOO O OO OOO OOOO O OOOO
Some who remember the 1960s were more into computers than counterculture. They may remember a time when stored text was less filling than now. One reason for that relative efficiency is given in the two-column mystery sentence above, encoded authentically for those days.
What was that reason?
What is this encoding?