2.1: Introduction
- Page ID
- 110790
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Information systems comprise six components: hardware, software, data, communication, people, and process. In this chapter, we will review hardware. Hardware is the tangible or physical parts of computing devices to function. We will review the hardware components of information systems, learn how it work, and discuss some current trends.
Computer hardware encompasses digital devices you can physically touch. This includes devices such as the following:
- desktop computers
- e-readers
- input devices, such as keyboards, mice, and scanners
- laptop computers
- mobile phones
- output devices such as 3d printers and speakers
- smartphones
- smartwatches
- Smart home devices
- storage devices, such as flash drives
- tablet computers
- virtual Reality headsets
Besides these more traditional computer hardware devices, many items that were once not considered digital devices are now becoming computerized. Digital technologies are now being integrated into many everyday objects, so the days of a device being labeled computer hardware may end. Examples of digital devices include automobiles, refrigerators, doorbells, and even soft-drink dispensers. Let's begin with some key metrics and terminologies used in describing units in devices before we get to look at each device in detail.
Digital Devices
A digital device is any physical equipment containing a computer or microcontroller; examples include smartphones, watches, and tablets. A digital device processes electronic signals that represent either a one ("on") or a zero ("off"). The presence of an electronic signal represents the "on" state; the absence of an electronic signal represents the "off" state.
Each one or zero is referred to as a bit (a contraction of a binary digit); a group of eight bits is a byte. The first personal computers could process 8 bits of data simultaneously; modern PCs can now process thousands of bits simultaneously. The larger the number of bits, the faster information can be processed simultaneously.
The system of numbering we are most familiar with is the decimal numeral system, also known as base-ten numbering. The decimal digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. In base-ten numbering, each position in the number represents a power of ten, going from right to left, with the far-right position representing 100 (ones), the next position from the right representing 101 (tens), then 102 (hundreds), then 103 (thousands), etc. The '10' means the base ten.
Example: How do we express the number 2053 or "two thousand and fifty-three" in base-ten format?
Going from left to right, the number 2053 in decimal represents: (2 x 1000) + (0 x 100) + (5 x 10) + (3 x 1) = 2000 + 0 + 50 + 3 = 2050, as shown in the table below:
| Position Exponent (note the '10' is the base ten) | 10 4 (read ten to the power of 4) | 10 3 | 10 2 | 10 1 | 10 0 |
|---|---|---|---|---|---|
| Answer | 2050 = | 2000 | +0 | +50 | + 3 |
| Decimal Number | 2 | 0 | 5 | 3 | |
| Decimal Representation | (2 *1000 (position value) ) | + (0 *100) | + (5 * 10) | + (3 * 1) | |
| Position Value in decimal | 10 to the power of 4 =10,000 | 1000 | 100 | 10 | 1 |
However, computers use the base-two number system, also known as binary. The binary digits are 0 and 1. Information is expressed by combinations of 'on' or 'off' electrical signals. The digit 0 represents 'off,' and 1 represents 'on.' Each position in a binary number represents a power of 2, going from right to left, with the far-right position representing 20 (ones), the next position from the right representing 21 (tens), then 22 (hundreds), then 23 (thousands), etc.
Example: What is the decimal value of the binary number 1010? (i.e., convert binary 1010 to a decimal value)
Going from left to right, the number 1010 in the binary represents: (1 * 8) + (0 * 4) + (1 * 2) + (0 * 1) =8 + 0 + 2 + 0 =10 in decimal, as shown in the table below:
| Position Exponent (note the '2' is the base two) | 2(read 2 to the power of 4) | 2 3 | 2 2 | 2 1 | 2 0 |
|---|---|---|---|---|---|
| Position Value in decimal | 2 to the power of 4 = 16 | 8 | 4 | 2 | 1 |
| Binary Number | 1 | 0 | 1 | 0 | |
| Convert to base ten decision | (1 * 8 (position value in decimal) ) | + (0 *4) | + (1 * 2) | + (0 * 1) | |
| Answer | 10 = | 8 | +0 | +2 | +0 |
As digital devices' capacities grew, new terms were developed to identify the capabilities of processors, memory, and disk storage space.
Let's get familiar with the terminologies to express the different sizes in bytes.
We discussed that computer systems operate using a binary number of systems with two digits: 0 and 1. Each digit is also called a bit. It takes 8 bits to describe a letter in the alphabet, such as the letter A. Eight bits is also called a byte. Prefixes were applied to the word byte to represent different orders of magnitude. The prefixes were initially meant to represent multiples of 1024 but have more recently been rounded to mean multiples of 1000.
| To Say | Use Prefix | Complete Expression |
|---|---|---|
| 1 byte | No prefix needed | 1 byte |
| One thousand bytes | kilo | 1 kilobyte |
| One million bytes | mega | 1 megabyte |
| One billion bytes | giga | 1 gigabyte |
| One trillion bytes | tera | 1 terabyte |
| One quadrillion bytes | peta | 1 petabyte |
| One quintillion bytes | exa | 1 exabyte |
| One sextillion bytes | zetta | 1 zettabyte |
| One septillion bytes | yotta | 1 yottabyte |