Addressing and residency mode

Addressing mode (AMODE) refers to the address length that a program is prepared to handle: 24-bit addresses, 31-bit addresses, or both (ANY). Programs with an addressing mode of ANY (AMODE ANY) must have been designed to receive control in either 24-bit or 31-bit addressing mode.

Residency mode (RMODE) specifies where a program is expected to reside in virtual storage. RMODE 24 indicates that a program is coded to reside in virtual storage below 16 MB. RMODE ANY indicates that a program is coded to reside in 24-bit virtual storage (below 16 MB) or 31-bit virtual storage (above 16 MB but below 2 GB).

For more information about AMODE and RMODE, see z/OS MVS Programming: Extended Addressability Guide. See also the appropriate programming guides for COBOL and PL/I for guidance about placing parameters above or below the 16 MB line.

With remote DL/I and DBCTL, programs can be AMODE(31) RMODE(ANY) with parameters above the 16 MB line, for both DL/I call and command level.