Sulfur dioxide (SO2) is irritating to eyes, skin and respiratory system. Volcanic Smog (vog) is produced from SO2 gas and is a hazard in Hawaii. Scientists monitor SO2 emission rates at KÄ«lauea volcano. Gas Plume during the 1984 eruption of Mauna Loa, Hawaii blocks out the sun.
Control Unit (CU) A control unit (CU) handles all processor control signals. It directs all input and output flow, fetches code for instructions from microprograms and directs other units and models by providing control and timing signals.
As Figure 1 shows, the central processing unit consists of two parts: The control unit and the arithmetic/logic unit. Each part has a specific function. Before we discuss the control unit and the arithmetic/logic unit in detail, we need to consider data storage and its relationship to the central processing unit.