Can undo editing in the calculator?

can i undo anything when i'm programming using the calculator?
like undo cancelling

Not exactly, you can go through a history of stuff you've entered by pressing 2nd enter, but it's kinda limited on what it shows. Other than that, there's nothing I know of >.>

There's an app called CalcSys that will let you edit programs even when they're archived... it copies them to RAM when you want to do that. Anyway, because of the perishable nature of the Flash Archive, it doesn't copy back until you press 2nd-Quit. Then it asks you if you want to save the changes back to the actual program. This is the closest solution I could find, but it will only undo all changes since you started editing.

I would most strongly suggest making a back up if you don't want it to get destroyed, and then have one that you tamper with. To do this, make a new program. Then hit the Rcl (2nd Store) and then go to the program you wish to recall. This will copy the entire program into that new program. Then, if you mess up a program and just want to go back, you can load the back up.