>>-MACHINE--=--+-----------+-----------------------------------><
               +-S370------+   
               +-S370XA----+   
               +-S370ESA---+   
               +-S390------+   
               +-S390E-----+   
               +-ZSERIES---+   
               +-ZS--------+   
               +-ZSERIES-2-+   
               +-ZS-2------+   
               +-ZSERIES-3-+   
               +-ZS-3------+   
               +-ZSERIES-4-+   
               +-ZS-4------+   
               +-ZSERIES-5-+   
               +-ZS-5------+   
               +-ZSERIES-6-+   
               '-ZS-6------'   

S370

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to System/370™ systems, including those with a vector facility. See OPTABLE=370.

S370XA

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to systems operating in System/370 extended-architecture mode, including those with a vector facility. See OPTABLE=XA.

S370ESA, S390, S390E

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to systems operating according to the ESA/370 or ESA/390 architecture, including those with a vector facility. See OPTABLE=ESA.

ZSERIES, ZS

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to Z/Architecture systems. See OPTABLE=ZOP.

ZSERIES-2, ZS-2

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to Z/Architecture systems with the Long-Displacement Facility, the DAT Enhancement Facility, the Message-Security Assist, and the HFP Multiply-Add/Subtract Facility. See OPTABLE=YOP.

ZSERIES-3, ZS-3

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to Z/Architecture systems with the decimal floating point facility. See OPTABLE=ZS3.

ZSERIES-4, ZS-4

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to Z/Architecture systems with the general instructions extensions facility. See OPTABLE=ZS4.

ZSERIES-5, ZS-5

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to Z/Architecture systems with the general instructions extensions facility and z196 instructions. See OPTABLE=ZS5.

ZSERIES-6, ZS-6

the assembler loads and uses the operation code table that contains the symbolic operation codes for the machine instructions specific to Z/Architecture systems with the general instructions extensions facility and zEnterprise EC12 (zEC12) instructions. See OPTABLE=ZS6.

Default

There is no default for the MACHINE option.

If you do not specify any value for the MACHINE option, the assembler takes the value you have specified for OPTABLE, if any, or the default OPTABLE=UNI, if not.

If you specify a value for MACHINE and a value for OPTABLE, and the values you specify are mutually exclusive (for example, you specify MACHINE=S390 and OPTABLE=ZOP) then the assembler will take the specification for MACHINE.