Variable: calc-undo-length
calc-undo-length is a customizable variable defined in calc.el.gz.
Value
100
Documentation
The number of undo steps that will be preserved when Calc is quit.
Source Code
;; Defined in /usr/src/emacs/lisp/calc/calc.el.gz
(defcustom calc-undo-length 100
"The number of undo steps that will be preserved when Calc is quit."
:type 'integer)