Next: Troubleshooting Commands, Previous: Error Messages, Up: Introduction [Contents][Index]

### 3.10 Multiple Calculators

It is possible to have any number of Calc mode buffers at once. Usually this is done by executing `M-x another-calc`, which is similar to `C-x * c` except that if a `*Calculator*` buffer already exists, a new, independent one with a name of the form `*Calculator*<n>` is created. You can also use the command `calc-mode` to put any buffer into Calculator mode, but this would ordinarily never be done.

The `q` (`calc-quit`) command does not destroy a Calculator buffer; it only closes its window. Use `M-x kill-buffer` to destroy a Calculator buffer.

Each Calculator buffer keeps its own stack, undo list, and mode settings such as precision, angular mode, and display formats. In Emacs terms, variables such as `calc-stack` are buffer-local variables. The global default values of these variables are used only when a new Calculator buffer is created. The `calc-quit` command saves the stack and mode settings of the buffer being quit as the new defaults.

There is only one trail buffer, `*Calc Trail*`, used by all Calculator buffers.