In April 1974 Xerox introduced the copier Xerox 4500. It had the same functions as the Xerox 4000, but it also had a sorter.
When more than one copy to more than one person was needed, sorting was necessary. The 4500 sorter operated online, gathering one-sided and/or two-sided copies. This means that when the copying was done, the copies was in the same sequence as the originals, ready for distribution. Hand collating was eliminated, and the total job time was shortened to just about the time it takes to make copies.