When EDT starts up, it reads the installation default startup command
file. The name of the file is always EDTSYS. The default name varies
depending on the system, as follows:
Default Name
-----------------
VAX/VMS SYS$LIBRARY:.EDT
RSX-11M & M-PLUS LB:[1,2].EDT
RSTS/E LB:.EDT
When opening the file, EDT combines the name and the default name
together into a complete file specification. On VAX/VMS, therefore, if
the logical name EDTSYS is defined, EDT will read from it rather than
from SYS$LIBRARY:EDTSYS.EDT.
The installation default startup command file should have SET COMMAND
EDTINI at its end, so that the user's initialization file will be read
after the installation default initialization file. If EDTSYS is not
found, EDT will try again using the name EDTINI, so there is no need for
an installation-default initialization file that just contains SET
COMMAND EDTINI.