This section describes how to control certain parameters of the GT.M run-time environment. This information is useful to anyone setting up a GT.M production environment. However if you are a first-time GT.M user, you can skip this section for now, and return to it when you are more familiar with the basics of executing an M program in the GT.M environment.
GT.M provides defaults for the GT.M working environment. These defaults or run-time parameters set the initial characteristics of the working environment used when compiling and linking an M image. The values for the defaults are changed by linking the image with an object module produced by assembling the macro GTM$DEFAULTS.M64.
GT.M installation places a distribution copy of GTM$DEFAULTS.M64 in GTM$DIST. In order to use GTM$DEFAULTS.M64, edit the distribution copy of this file or its replica. The list of items in a GTM$DEFAULTS.M64 must be complete and correctly spelled to avoid "symbol-multiply-defined" errors upon relinking. New versions of GT.M may have additional default parameters. In this case, make your modifications in the new GTM$DEFAULTS.M64, or add the new parameters to your edited copy.
The run-time parameters can change the following process characteristics:
Stack space.
BG buffer space.
Size of cache for storing compiles from past indirections.
Initial string pool size.
Maximum time that GT.M may defer a terminal write.
Whether to maintain $X and $Y for <LF>, <FF>, <CR> and <BS> characters produced by $C() and W *, and whether to ignore escape sequences when updating $X and $Y.
Whether to provide alternative handling for <CTRL-U>.
Whether to treat undefined variables as null strings.
Whether or not <CTRL-C> is enabled.
Whether or not Break messages are enabled.
Whether or not labels are case sensitive.
Whether or not local variables accept null subscripts.