### 1.4 Emacs support ¶

MDK includes extensive support for Emacs. Upon installation, all the elisp code is installed in `PREFIX/share/mdk`, where `PREFIX` stands for your installation root directory (e.g. `/usr/local`). You can copy the elisp files to a directory that is in your load-path, or you can add the above directory to it. Assuming that the installing prefix is `/usr/local`, you can do it by adding to your `.emacs` file the following line:

    (setq load-path (cons "/usr/local/share/mdk" load-path))

`MIXAL` programs can be written using Emacs and the elisp program `share/mdk/mixal-mode.el`, contributed by Pieter E. J. Pareit. It provides font locking, interactive help, compiling assistance and invocation of the `MIX` virtual machine via a new major mode called `mixal-mode`. To start `mixal-mode` automatically whenever you edit a `MIXAL` source file, add the following lines to your `.emacs` file:

    (autoload 'mixal-mode "mixal-mode" t)
    (add-to-list 'auto-mode-alist '("\\.mixal\\'" . mixal-mode))

In addition, `mixvm` can be run within an Emacs GUD buffer using the elisp program `share/mdk/mixvm.el`, contributed by Philip E. King. `mixvm.el` provides an interface between MDK’s `mixvm` and Emacs, via GUD. Place this file in your load-path, optionally adding the following line to your `.emacs` file:

    (autoload 'mixvm "mixvm" "mixvm/gud interaction" t)