Abstract: A controller for a heat pump system wherein the controller has a variable capacity control capability that responds to thermostat output signals. The variable capacity controller computes real-time performance parameters at variable capacity heating/cooling load conditions of the heat pump system. A defrost controller calculates an optimum heat pump operating time period between successive defrost cycles during a heating mode of the heat pump. Such values are calculated as a function of sensed time, temperature and variable capacity operating conditions which are calculated by the variable capacity controller. The controller preferably has a manual mode for verifying correct operation of each actuator of the heat pump system, as a function of a sequenced input signal, while the heat pump system is in a shutdown mode.

Abstract: A controller for a gas heat pump system wherein the controller has a variable capacity control capability that responds to thermostat output signals. The variable capacity controller computes real-time performance parameters at variable capacity heating/cooling load conditions of the gas heat pump system. A defrost controller calculates a maximum heat pump operating time period between successive defrost cycles and a minimum heat pump operating time period of each defrost cycle, during a heating mode of the gas heat pump. Such values are calculated as a function of sensed time, temperature and variable capacity operating conditions which are calculated by the variable capacity controller. The controller preferably has a manual mode for verifying correct operation of each actuator of the gas heat pump system, as a function of a sequenced input signal, while the gas heat pump system is in a shutdown mode.

Abstract: A dual cache memory system employs a search cache addressed by virtual addresses, the search cache containing a plurality of recently used, pre-translated physical addresses. A map cache contains virtual address bound data and relocation data to map the virtual address space to physical address space. Upon receipt of a virtual address, a search of the search cache is first conducted to retrieve the associated physical address if it has been already translated. If not, a binary search of the memory map using the map cache is conducted to find that map entry whose virtual address bound identifies the region of virtual addresses containing the virtual address being mapped. The physical address is constructed from the retrieved relocation data and virtual address, and is written into the search cache for future use.