sentences:  According to source code listings of the SCOPE version of O26, it was written in 1967 by CDC programmers Greg Mansfield and David Cahlander.An independently developed full screen editor was written in 1967 by Edgar T. Irons and Franz M. Djorup at the Institute for Defense Analyses to run on a CDC 6600.This editor was described in a later ACM article as operating ""from low-cost cathode-ray tube entry and display stations with keyboard and 13 function buttons.""