Class M1 commands are commands that are attached in the *MASTER*
address space, and are considered essential to clearing a backlog
of other commands:
- DISPLAY AUTOR
- DISPLAY GRS
- DISPLAY MPF
- DISPLAY MSGFLD
- DISPLAY SLIP
- DISPLAY XCF
- DUMP
- DUMPDS
- QUIESCE
- SET
- SETMF
- SETXCF
- SLIP
- VARY XCF