Page 4 - Computer Programming

TEACHING TIPS

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
Bus
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