A PC routine must be defined so that it may receive control from supervisor state, key 0.
| Environmental factor | Requirement |
|---|---|
| State and key: | State and Key as defined via the ETDEF for the PC |
| Cross memory mode: | If it is not a space switcher PC, then Home = Primary = Secondary. Otherwise, the ETDEF of the PC will define the cross memory mode. |
| AMODE: | Defined via the ETDEF for the PC |
| ASC mode: | ASC mode defined via ETDEF for the PC |