The History of the "Undo" Function?

TheLocustNMI asks: "So, earlier today as I was typing out some magnum opus of a stored procedure, I highlighted to copy it, and hit SPACE instead of Ctrl-C. Without thinking, I hit Ctrl-Z to 'undo' my folly. Pausing a moment to reflect, I realized that I own countless hours of thanks to whomever came up with the "undo" button. In short -- my question is this -- where did it come from? What are the earliest implementations of the 'undo'? (a quick googling returns this page, a cornucopia of undo and history related treatises)"

Comments

Re:I'd like to know

[exp(pi*sqrt(163))]

Here's what one well known Academy Award winning 3D package does. Every command is an object. When you execute a command that object is stored in a 'history'. The command has two methods, a do() method and an undo() method. As long is the object remains alive it can undo or redo the associated operation.

"Commit" = "Undo"

[dpbsmith]

I remember a rudimentary CAD program for the Apple ][+, circa 1982 or 1983. I wish I could remember the name...

I personally first encountered "Undo" on the Mac in 1984. But this CAD program had a function... they didn't call it "commit." I don't remember the exact language they DID use.

The idea was that you never had to worry about making mistakes, because every action you took was tentative, and would be shown to you as a preview before taking effect.

So you'd give a command to draw a line, you'd see the line onscreen, and you could either accept it (in which case it became part of the drawing) or reject it (in which case it disappeared).

The weird thing about all this is that logically, it is exactly equivalent to an "undo" function.

And the even weirder thing is that while an "undo" function feels empowering and liberating... when the exact same function was presented as "tentative action, preview, accept/reject" it felt clumsy and laborious.

To me, anyway.