You can save all of the current mode settings in your Calc init file
(the file given by the variable calc-settings-file, typically
~/.emacs.d/calc.el) with the m m (calc-save-modes)
command. This will cause Emacs to reestablish these modes each time
it starts up. The modes saved in the file include everything
controlled by the m and d prefix keys, the current
precision and binary word size, whether or not the trail is displayed,
the current height of the Calc window, and more. The current
interface (used when you type C-x * *) is also saved. If there
were already saved mode settings in the file, they are replaced.
Otherwise, the new mode information is appended to the end of the
file.
The m R (calc-mode-record-mode) command tells Calc to
record all the mode settings (as if by pressing m m) every
time a mode setting changes. If the modes are saved this way, then this
“automatic mode recording” mode is also saved.
Type m R again to disable this method of recording the mode
settings. To turn it off permanently, the m m command will also be
necessary. (If Embedded mode is enabled, other options for recording
the modes are available; see Mode Settings in Embedded Mode.)
The m F (calc-settings-file-name) command allows you to
choose a different file than the current value of calc-settings-file
for m m, Z P, and similar commands to save permanent information.
You are prompted for a file name. All Calc modes are then reset to
their default values, then settings from the file you named are loaded
if this file exists, and this file becomes the one that Calc will
use in the future for commands like m m. The default settings
file name is ~/.emacs.d/calc.el. You can see the current file name by
giving a blank response to the m F prompt. See also the
discussion of the calc-settings-file variable; see Customizing Calc.
If the file name you give is your user init file (typically ~/.emacs), m F will not automatically load the new file. This is because your user init file may contain other things you don’t want to reread. You can give a numeric prefix argument of 1 to m F to force it to read the file no matter what. Conversely, an argument of -1 tells m F not to read the new file. An argument of 2 or -2 tells m F not to reset the modes to their defaults beforehand, which is useful if you intend your new file to have a variant of the modes present in the file you were using before.
The m x (calc-always-load-extensions) command enables a mode
in which the first use of Calc loads the entire program, including all
extensions modules. Otherwise, the extensions modules will not be loaded
until the various advanced Calc features are used. Since this mode only
has effect when Calc is first loaded, m x is usually followed by
m m to make the mode-setting permanent. To load all of Calc just
once, rather than always in the future, you can press C-x * L.
The m S (calc-shift-prefix) command enables a mode in which
all of Calc’s letter prefix keys may be typed shifted as well as unshifted.
If you are typing, say, a S (calc-solve-for) quite often
you might find it easier to turn this mode on so that you can type
A S instead. When this mode is enabled, the commands that used to
be on those single shifted letters (e.g., A (calc-abs)) can
now be invoked by pressing the shifted letter twice: A A. Note
that the v prefix key always works both shifted and unshifted, and
the z and Z prefix keys are always distinct. Also, the h
prefix is not affected by this mode. Press m S again to disable
shifted-prefix mode.