### 4.2 GUD integration ¶

If you are an Emacs user and write your MIXAL programs using this editor, you will find the elisp program `mixvm.el` quite useful17. `mixvm.el` allows running the MIX virtual machine `mixvm` (see `mixvm`, the MIX computer simulator) inside an Emacs GUD buffer, while visiting the MIXAL source file in another buffer.

After installing `mixvm.el` (see Emacs support), you can initiate an MDK/GUD session inside Emacs with the command

    M-x mixvm

and you will have a `mixvm` prompt inside a newly created GUD buffer. GUD will reflect the current line in the corresponding source file buffer.