Configuration of the modifier keys

TeXmacs uses five major keyboard modifiers: shift, control, alternate, meta and hyper, which are abbreviated as S-, C-, A-, M- and H-. The shift and control keys are present on virtually all keyboards and the alternate key on almost all. Most keyboards for PC's nowadays also have a windows key, which is usually equivalent to meta for TeXmacs.

Before reconfiguring your keyboard, you should first check that this is indeed necessary. If you have keys which correspond to shift, control, alternate and meta in a suitable way, then you probably do not want to do anything. A possible exception is when you want to use a simple key like caps-lock for typing mathematical symbols. In that case, you should map caps-lock to hyper.

In order to reconfigure the keyboard, you simply select the logicial modifier that you want to correspond to a given physical key in Edit→Preferences→Keyboard. For instance, selecting Windows key→Map to M modifier, the windows key will correspond to the meta modifier. Similarly, when selecting Caps-lock key→Map to H modifier, the caps-lock key will correspond to the hyper modifier.

Unfortunately, X Window only allows system-wide reconfiguration. Consequently, if you reconfigure the caps-lock key inside TeXmacs, then the new behaviour of caps-lock will affect all other applications too. It is therefore important to reconfigure only those keys which you do not use for something else in other applications. For instance, the windows key is not used by many applications, so it generally does not do any harm to reconfigure it. You may also prefer to perform an appropriate system-wide configuration. This can be done using the xmodmap command; see the corresponding manual page for more information.

In certain cases, you already have keys on your keyboard which correspond to alternate, meta and hyper, but not in the way you want. This can be done by remapping the A-, M- and H- prefixes to other logical modifiers in the first group of submenus of Edit→Preferences→Keyboard.

For instance, for Emacs compatability, you might want to permute the meta or windows key with alternate without making any system-wide changes. This can be done by finding out which modifiers correspond to these keys; usually this will be Mod1 for alternate and Mod4 for meta or windows. We next perform the necessary permutation in Edit→Preferences→Keyboard, by selecting A modifier→Equivalent for Mod4 and M modifier→Equivalent for Mod1.