T-Square is an early drafting program written by Peter Samson assisted by Alan Kotok and possibly Robert A. Saunders while they were students at the Massachusetts Institute of Technology and members of the Tech Model Railroad Club.T-Square was written for the PDP-1 computer and its Type 30 precision CRT that Digital Equipment Corporation donated to MIT in 1961. It is unlikely that many people have had the opportunity to use T-Square although Samson has said the group drew some schematics.