OVLY: Overlay option

The OVLY option allows you to create a program module in overlay format. A program with the overlay attribute is placed in an overlay structure as directed by binder OVERLAY control statements. The program module cannot be refreshed, reenterable, or serially reusable. AMODE(24) and RMODE(24) are the only valid addressing and residence options.

If the overlay attribute is specified and no OVERLAY control statements are found in the binder input, the attribute is ignored.

The overlay attribute must be specified for overlay processing. If this attribute is omitted, the OVERLAY and INSERT statements are not considered valid, and the module is not put into overlay structure.

You specify the overlay attribute by coding OVLY in the PARM field as follows:

{OVLY | OVLY=NO | NOOVLY}

See Designing and specifying overlay programs, for information on the design and specification of an overlay structure.

OVLY=NO is the default value and can also be specified with the keyword NOOVLY.

Note: The OVLY option overrides any specification of the COMPAT option. That is, if you specify the options COMPAT (COMPAT=any value) and OVLY at the same time, OVLY prevails and the module is saved in PM1 format if the SYSLMOD data set is a PDSE. Otherwise it is saved as a load module in a PDS. For more information on COMPAT, see COMPAT: Binder level option.