If a device number is not valid, bit 0 of the FLAG byte is set
to 1.
Register 15 contains one of the following return codes:
- Code
- Meaning
- 0
- The specified input is correct.
- 4
- The specified unit name is not valid.
- 8
- Unit name has incorrect units assigned.
- 20
- One or more device numbers are not valid.
- 28
- The required input is not specified or is not valid.