For IBM® 3720 and 3745 communication controllers, the VARY ACT command enables you to control whether the NCP is loaded from the host or from the 3720 or 3745 Communication Controller external disk storage.

The first NCP load can be from the host or a diskette. For more information about loading an NCP from a diskette, see the NCP, SSP, and EP Generation and Loading Guide. For communication controllers other than 3720s or 3745s, the NCP can be loaded only from the host.