History of the undo command FYI

I thought people would enjoy this excerpt from a New York Times
article:

"Our expectations that any action can be taken back have been primed
by a few decades of personal computing, which injected the founding
metaphor of “undoing” into the common consciousness. An early glimmer
of our Age of Undoing appeared in a prescient 1976 research report by
Lance A. Miller and John C. Thomas of I.B.M., drably titled
“Behavioral Issues in the Use of Interactive Systems.” “It would be
quite useful,” Miller and Thomas observe, “to permit users to ‘take
back’ at least the immediately preceding command (by issuing some
special ‘undo’ command).” Useful indeed!

"The undo command would become a crucial feature of text editors and
word processors in the PC era, assigned the now-familiar keyboard
shortcut of Control-Z by programmers at the research center Xerox
PARC. In the software of the ’80s, some undo commands became
“multi­level,” allowing users to take back a whole series of actions
(called the undo stack), not just the most recent one. Ad-hoc un-
verbs began to emerge for these reversible innovations. In 1984, the
software company NewStar introduced the unerase command for its
word-processing program NewWord, while I.B.M.’s VisiWord countered
with undelete. From there it was a quick step to unbolding,
unitalicizing and even un-underlining your errantly formatted
text."

Source:
http://www.nytimes.com/2009/09/20/magazine/20FOB-onlanguage-t.htm?_r=1