152 Understanding the Numbers
as phone numbers and addresses. These same capabilities are also available on
PCs, most typically in software products such as Microsoft Outlook, which also
includes e-mail. Most PDAs come with the ability to transfer appointments and
contact information bidirectionally between the PDA and a PC.
Computer Components
Exhibit 5.1 shows a schematic rendition of the components in a computer sys-
tem. This section of Chapter 5 will explain the basic functioning of these com-
ponents and present some of the tradeoffs that you will face in making an
intelligent decision to buy a computer system.
CPU
All basic computers have a central processing unit (CPU).The CPU is the basic
logical unit that is the computer ’s “brain.” As mentioned earlier, it is usually
provided by Intel Corporation or one of the clone-chip manufacturers such as
AMD. While Intel enjoys the lion’s share of the market, the clones have
recently made significant inroads by offering lower prices for comparable
products. State-of-the-art CPUs manage to integrate onto one thumbnail sized
silicon chip tens of millions of electronic components. CPUs such as the Pen-
tium come in different speeds, expressed in megahertz or gigahertz (millions
or billions of cycles per second). Speed represents how fast the CPU is capable
of performing its various calculations and data manipulations. A typical CPU
today operates at between 800 MHz and 1.5 GHz.
EXHIBIT 5.1 Layout of a personal computer.
CPURAMHard
driveCD ROM/
DVD driveMonitorPhone
jackKeyboard MouseDisk controller
Display adapterModem
Sound cardSpeaker SpeakerNetwork adapter Network
jack