PART I: WHAT IS AN INFORMATION SYSTEM?
Chapter 2: Hardware
Upon successful completion of this chapter, you will be able to:
• Describe information systemshardware;
• Identify the primary components of a computer and the functions they perform;
and
• Explain the effect of the commoditization of the personal computer.
Introduction
As you learned in the first chapter, an information system is made up of five components: hardware, software, data, people, and process. The physical parts of computing devices – those that you can actually touch – are referred to as hardware. In this chapter, you will take a look at this component of information systems, learn a little bit about how it works, and discuss some of the current trends surrounding it.
As stated above, computer hardware encompasses digital devices that you can physically touch. This includes devices such as the following:
• desktop computers
• laptop computers
• mobile phones
• tablet computers
• e-readers
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• storage devices, such as flash drives
• input devices, such as keyboards, mice, and scanners
• output devices such as printers and speakers.
Besides these more traditional computer hardware devices, many items that were once not considered digital devices are now becoming computerized themselves. Digital technologies are being integrated into many everyday objects so the days of a device being labeled categorically as computer hardware may be ending. Examples of these types of digital devices include automobiles, refrigerators, and even beverage dispensers. In this chapter, you will also explore digital devices, beginning with defining what is meant by the term itself.
Digital Devices
A digital device processes electronic signals into discrete values, of which there can be two or more. In comparison analog signals are continuous and can be represented by a smooth wave pattern.
You might think of digital (discrete) as being the opposite of analog.
Many electronic devices process signals into two discrete values, typically known as binary. These values are represented as either a one (“on”) or a zero (“off”). It is commonly accepted to refer to the on state as representing the presence of an electronic signal. It then follows that the off state is represented by the absence of an electronic signal. Note: Technically, the voltages in a system are evaluated with high voltages converted into a one or on state and low voltages converted into a zero or off state.
Each one or zero is referred to as a bit (a blending of the two words
“binary” and “digit”). A group of eight bits is known as a byte. The first personal computers could process 8 bits of data at once. The number of bits that can be processed by a computer’s processor at one time is known as word size. Today’s PCs can process 64 bits of data at a time which is where the term 64-bit processor comes from.
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You are most likely using a computer with a 64-bit processor.
Sidebar: Understanding Binary
The numbering system you first learned was Base 10 also known as Decimal. In Base 10 each column in the number represents a power of 10 with the exponent increasing in each column as you move to the left, as shown in the table:
Thousands Hundreds Tens Units 103 102 101 100
The rightmost column represents units or the values zero through nine. The next column from the left represents tens or the values teens, twenties, thirties, etc., followed by the hundred’s column (one hundred, two hundred, etc.), then the thousands column (one thousand, two thousand) etc. Expanding the table above, you can write the number 3456 as follows:
Thousands Hundreds Tens Units 103 102 101 100
3 4 5 6
3000 400 50 6
Computers use the Base 2 numbering system. Similar to Base 10, each column has a Base of 2 and has an increasing exponent value moving to the left as shown in the table below:
Two cubed Two Two Units squared
23 22 21 20
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The rightmost column represents 20 or units (1). The next column from the left represents 21 twos or (2). The third column represents 22 or (4) and the fourth column represents 23 or (8). Expanding the table above, you can see how the decimal number 15 is converted to 1111 in binary as follows:
Two cubed Two Two Units squared
23 22 21 20
1 1 1 1
8 4 2 1
8 + 4 + 2 + 1 = 15
Understanding binary is important because it helps us understand how computers store and transmit data. A “bit” is the lowest level of data storage, stored as either a one or a zero. If a computer wants to communicate the number 15, it would need to send 1111 in binary (as shown above). This is four bits of data since four digits are needed. A “byte” is 8 bits. If a computer wanted to transmit the number 15 in a byte, it would send 00001111. The highest number that can be sent in a byte is 255, which is 11111111, which is equal to 27 + 26 + 25 + 24 + 23 + 22 + 21 + 20 .
As the capacities of digital devices grew, new terms were developed to identify the capacities of processors, memory, and disk storage space. Prefixes were applied to the word byte to represent different orders of magnitude. Since these are digital specifications, the prefixes were originally meant to represent multiples of 1024 (which is 210), but have more recently been rounded for the sake of simplicity to mean multiples of 1000, as shown in the table below:
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Prefix Represents Example kilo one
thousand kilobyte=one thousand bytes mega one million megabyte = one
million bytes giga one billion gigabyte = one billion bytes tera one trillion terabyte = one
trillion bytes peta one
quadrillion petabyte = one quadrillion bytes
exa one
quintillion exabyte = one quintillion bytes zetta one
sextillion zettabyte = one sextillion bytes yotta one
septillion yottabyte = one septillion bytes
Tour of a PC
All personal computers consist of the same basic components: A Central Processing Unit (CPU), memory, circuit board, storage, and input/output devices. Almost every digital device uses the same set of components, so examining the personal computer will give you insight into the structure of a variety of digital devices. Here’s a “tour” of a personal computer.
Processing Data: The CPU
The core of a computer is the Central Processing Unit, or CPU.
It can be thought of as the “brains” of the device. The CPU carries out the commands sent to it by the software and returns results to be acted upon.
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Intel Core i7 CPU
The earliest CPUs were large circuit boards with limited functionality.
Today, a CPU can perform a large variety of functions. There are two primary manufacturers of CPUs for personal computers: Intel and Advanced Micro Devices (AMD).
The speed (“clock time”) of a CPU is measured in hertz. A hertz is defined as one cycle per second. A kilohertz (abbreviated kHz) is one thousand cycles per second, a megahertz (mHz) is one million cycles per second, and a gigahertz (gHz) is one billion cycles per second. The CPU’s processing power is increasing at an amazing rate (see the sidebar about Moore’s Law).
Besides a faster clock time, today’s CPU chips contain multiple processors. These chips, known as dual-core (two processors) or quad-core (four processors), increase the processing power of a computer by providing the capability of multiple CPUs all sharing the processing load. Intel’s Core i7 processors contain 6 cores and their Core i9 processors contain 16 cores. This video shows how a CPU works.
Sidebar: Moore’s Law and Huang’s Law
As you know computers get faster every year. Many times, we are not sure if we want to buy today’s model because next week it won’t be the most advanced any more. Gordon Moore, one of the founders of Intel, recognized this phenomenon in 1965, noting that microprocessor transistor counts had been
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doubling every year.1 His insight eventually evolved into Moore’s Law:
The number of integrated circuits on a chip doubles every two years.
Moore’s Law has been generalized into the concept that computing power will double every two years for the same price point. Another way of looking at this is to think that the price for the same computing power will be cut in half every two years.
Moore’s Law has held true for over forty years (see figure below).
The limits of Moore’s Law are now being reached and circuits cannot be reduced further. However, Huang’s Law regarding Graphics Processors Units (GPUs) may extend well into the future. Nvidia’s CEO Jensen Huang spoke at the GPU Technology Conference in March 2018 announcing that the speed of GPUs is increasing faster than Moore’s Law. Nvidia’s GPUs are 25 times faster than five years ago. He admitted that the advancement is because of advances in architecture, memory technology, algorithms, and interconnects.2