The functional unit in a processor that does the computing. It reads instructions and data from memory and performs the arithmetic and logic operations defined by the instruction. A complete computer system includes CPU, main memory, clock circuits, and input and output devices. A special ROM memory that can be erased when exposed to strong doses of ultraviolet or UV light. Erasing requires physically removing the device and placing it under a strong UV light for several minutes.
Programming requires placing it into a special PROM programmer.
Special ROM memory that can be erased and programmed electrically, often the original system socket. H High Level Language HLL coding requires an editor and an HLL compiler program. The compiler program takes the HLL instructions and translates them into sequences of 1 's and 0's that the CPU can understand. The final output is machine code or binary executable code. One wire, SDA, carries the data between components and the other wire, SCL, carries the clock timing information that synchronizes the data transmission at speeds of up to 100 kilobits per second.