Page 4 - Computer Programming
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                                                   1.1  Concepts and Terminology of a Computer  3  Q   Explain that the CPU is much like
                                                                                           the human brain. The brain sends
                     Q     Input devices (such as the mouse and keyboard)
                     Q     Output devices (such as monitors and printers)                  and receives messages to control the
                     Q     Communication devices (such as modems and network interface cards)  body and tell it what to do. Likewise,
                                                                                           the CPU controls the actions of the
                                                                                           other components.
                    Storage  Memory  CPU  Communication  Input  Output
                    Devices             Devices  Devices  Devices                        Q   Demonstrate the concept of the
                  e.g., Disk, CD,      e.g., Modem  e.g., Keyboard,  e.g., Monitor,
                   and Tape             and NIC  Mouse   Printer                           binary number system using an
                  FIGURE 1.1   A computer consists of a CPU, memory, storage devices, input   8–flap foldable. Each switch has
                         devices, output devices, and communication devices.
                                                                                           only 2 settings: on or off, 0 or 1. The
                                                                                           combination of these eight switches
                   A computer’s components are interconnected by a subsystem called a bus.   bus
                  You can think of a bus as a sort of system of roads running among the com-  is the storage unit called a byte.
                  puter’s components. Data and power travel along the bus from one part of the
                  computer to another. In personal computers, the bus is built into the com-  Q   Practice calculating several bytes
                  puter’s motherboard, which is a circuit case that connects all of the parts of a   motherboard
                  computer together.                                                       with the foldable.
                  Central Processing Unit                                                Q   When a number cannot fit into
                  The central processing unit (CPU) is the computer’s brain. It retrieves instructions   CPU  a single byte, you must add more
                  from memory and executes them. The CPU usually has two components: a
                                                                  control unit
                  control unit and an  arithmetic/logic unit. The control unit controls and coor-  arithmetic/logic unit  bytes! Demonstrate with a second
                  dinates the actions of the other  components. The arithmetic/logic unit per-
                  forms numeric operations (addition, subtraction, multiplication, division)   8-bit foldable.
                  and logical operations (comparisons).
                   Today’s CPUs are built on small silicon semiconductor chips that contain
                  millions of tiny electric switches, called transistors, for processing information.  transistors
                   Every computer has an internal clock, which emits electronic pulses at a
                  constant rate. These pulses are used to control and synchronize the pace of
                  operations. A higher clock speed enables more instructions to be executed in   speed
                  a given period of time. The unit of  measurement of clock speed is the hertz   hertz
                  (Hz), with 1 hertz equaling 1 pulse per second. In the 1990s,  computers meas-
                  ured clocked speed in megahertz (MHz), but CPU speed has been improving   megahertz
                  continuously; the clock speed of a computer is now usually stated in gigahertz   gigahertz
                  (GHz). Intel’s newest processors run at about 3 GHz.
                   CPUs were originally developed with only one core. The core is the part   core
                  of the processor that performs the reading and executing of instructions. In
                  order to increase CPU processing power, chip manufacturers are now produc-
                  ing CPUs that contain multiple cores. A multicore CPU is a single component
                  with two or more independent cores. Today’s consumer computers typically
                  have two, three, and even four separate cores. Soon, CPUs with dozens or even
                  hundreds of cores will be affordable.

                                                           CHAPTER 1     Q  Computer Programming and the Workplace 3
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