Microprocessor Chips

possible while pulling it forward for removal.” This action ensures that none of the internal wires, cables, or connectors are accidentally pulled loose and avoids possible damage to the components already installed inside the system unit. So that you will have a better understanding and appreciation for this microcomputer, we will take a closer look at microprocessor chips and see how they differ from one another. We will also examine what all this means to you from a communications specialist’s standpoint. Microprocessor Chips All microcomputer systems are driven by one or more microprocessor chips. A microprocessor chip is made up of thousands of integrated circuits that contain all of the essential elements of a central processing unit (figure 1-10). These include the control logic, instruction decoding, and arithmetic-processing circuitry. To be useful, the microprocessor chip (which is no bigger than your fingernail) must be mounted onto what is called a carrier package (figure 1-11). This carrier package along with other chips-memory chips (RAM and ROM) and I/O integrated circuit chips—are plugged into specific socket locations on a circuit board called the system board or the motherboard (figure 1-12). Figure 1-10.—A typical microprocessor computer chip. Figure 1-11.—A microprocessor being mounted onto the carrier package. Of all the boards in the microcomputer, the system board is the most important. But what are the functions of the microprocessor chip? Are all microprocessor chips designed to perform the same functions? Basically, yes; but there are some significant differences in how they perform their functions. You should be aware of these differences, especially if you will be working with several different types of micros. A chip, is a chip, is a chip, OR IS IT? Computer chips, like everything else in data processing, have some rather unique and unusual names; names like Zilog Z-80A, Intel 80C88, MOS Technology 6502, Motorola 68000, and so on. Some chip names contain letters and numbers. Others contain only numbers. Having the right microprocessor chip in your computer Figure 1-12.—The system/motherboard showing placement of the microprocessor, RAM, ROM, and integrated circuit chip. 1-13