Abstract: Processing within a computing environment that supports pageable guests is facilitated. Processing is facilitated in many ways, including, but not limited to, associating guest and host state information with guest blocks of storage; maintaining the state information in control blocks in host memory; enabling the changing of states; and using the state information in management decisions. In one particular example, the guest state includes an indication of usefulness and importance of memory contents to the guest, and the host state reflects the ease of access to memory contents. The host and guest state information is used in managing memory of the host and/or guests.

Abstract: Input/output (I/O) operation requests from pageable storage mode guests are interpreted without host intervention. In a pageable mode virtual environment, requests issued by pageable storage mode guests are processed by one or more processors of the environment absent intervention from one or more hosts of the environment. Processing of the requests includes manipulating, by at least one processor on behalf of the guests, buffer state information stored in host storage. The manipulating is performed via instructions initiated by the guests and processed by one or more of the processors.

Abstract: Host page management assist functions are employed to manage storage of a pageable mode virtual environment. These functions enable storage to be managed by a processor of the environment absent intervention of a host of the environment. The functions include a resolve host page function; a pin function; and unpin functions.

Abstract: A connector block having an alarm-isolation circuit includes a first alarm input terminal, a second alarm input terminal, a first alarm output terminal, a second alarm output terminal, and at least one diode. The first and second alarm input terminals are operable for electrical connection with a two-wire alarm input. The first and second alarm output terminals are electrically connected respectively to the first and second alarm input terminals. The at least one diode is electrically connected between the first alarm input terminal and a first alarm output terminal, thereby forming a portion of the alarm-isolation circuit. The one alarm-isolation circuit is capable of forwarding an electrical signal to a remote location. In other embodiments, a diode is used between each alarm input terminal and alarm output terminal, thereby inhibiting feedback among the alarm output terminals and the associated alarm input terminal.

Abstract: A connector block having an alarm-isolation circuit includes a first alarm input terminal, a second alarm input terminal, a first alarm output terminal, a second alarm output terminal, and at least one diode. The first and second alarm input terminals are operable for electrical connection with a two-wire alarm input. The first and second alarm output terminals are electrically connected respectively to the first and second alarm input terminals. The at least one diode is electrically connected between the first alarm input terminal and a first alarm output terminal, thereby forming a portion of the alarm-isolation circuit. The one alarm-isolation circuit is capable of forwarding an electrical signal to a remote location. In other embodiments, a diode is used between each alarm input terminal and alarm output terminal, thereby inhibiting feedback among the alarm output terminals and the associated alarm input terminal.