MODESET macro - is type 6, gets no lock.
Calls module IEAVMODE, entry point IGC107.
| 0-2 | Reserved (must be zero). | ||
| 3 | Indicator bits: | ||
| 0000 | .... | No action. | |
| 0001 | .... | Invalid. | |
| 0010 | .... | Place the TCB key in the RBOPSW field of the RB. | |
| 0011 | .... | Set the RBOPSW key to zero. | |
| .... | 0000 | No action. | |
| .... | 0100 | Turn on the state bit in RBOPSW field of the RB (problem state). | |
| .... | 1000 | Invalid. | |
| .... | 1100 | Turn off the state bit in RBOPSW field of the RB (supervisor state). | |