The following MACRO program can be used to obtain symbols in
    addition to those in SYS$BASE_IMAGE.EXE:

    .TITLE GLOBALS
    $PHDDEF GLOBAL          ; Process header definitions
    $DDBDEF GLOBAL          ; Device data block
    $UCBDEF GLOBAL          ; Unit control block
    $VCBDEF GLOBAL          ; Volume control block
    $ACBDEF GLOBAL          ; AST control block
    $IRPDEF GLOBAL          ; I/O request packet
    ; More can be inserted here
    .END

    Use the command below to generate an object module file
    containing the globals defined in the program.

    $MACRO GLOBALS+SYS$LIBRARY:LIB/LIBRARY /OBJECT=GLOBALS.STB

    SDA can also read symbols from an image .EXE or .STB produced by
    the linker. The STB and EXE files only contain universal symbols.
    The STB file, however, can be forced to have global symbols for
    the image if the SYMBOL_TABLE=GLOBAL option is used in the linker
    options file.

    If you do not specify a file type, .STB is used by default. If a
    .STB file is not found, SDA then tries a .EXE file.

    A number of ready-built symbol table files ship with OpenVMS
    Alpha. They can be found in the directory SYS$LOADABLE_IMAGES,
    and all have names of the form xyzDEF.STB. Of these files, SDA
    automatically reads REQSYSDEF.STB on activation. The symbols in
    the other files can be added to SDA's symbol table using the READ
    command.