Section 3: Computer Hardware and History
3.3 ( Components of Computer Hardware: Peripheral Devices)
Various units that support the input and output functions are collectively called peripheral devices and comprise the I/O unit. Input devices, such as keyboards, mouses, and sensors, are used to move data into computers. Output devices, such as printers and monitors, are used to move information out of computers.
3.3 (Types of Computers: Workstation)
A workstation is a single-user computer designed for technical or scientific applications. It has a faster microprocessor, a large amount of RAM, and high-speed graphics cards. It generally performs a specific job with great expertise. Graphics, music, and engineering design departments often use this type of system.
3.1 (Computer History and Hardware: The Abacus)
One of the earliest computing devices was the abacus, probably first used in China and then by the early Greek and Roman civilizations. The abacus consists of strings of beads strung on rods, which are mounted on a rectangular frame. As the beads are moved back and forth on the rod, their positions represent stored values. To carry out calculations, the abacus needs a human operator; otherwise, it is merely data storage. Thus, the abacus must be combined with a human to form a system whose purpose is carrying out additions.
3.3 (Types of Computers: Supercomputers)
Supercomputers are the biggest and fastest computers, designed to process huge amounts of data. They are built as a system of thousands of interconnected processors. Supercomputers are particularly useful in scientific and engineering applications such as weather forecasting, scientific simulations, and nuclear energy research.
3.3 ( The Components of the System Unit: CPU)
You have already learned that the CPU is the brain of the computer. It executes instructions and tells other components what to do.
3.3 (Types of Computers: Mainframe Computers)
Mainframe computers are designed to support hundreds or thousands of users simultaneously. They also support multiple programs at the same time, making them useful to big organizations that manage and process high volumes of data.
3.2 (Introduction to Computer Hardware: Graphic Processor Unit)
Especially important for 3D rendering, the graphics processing unit (GPU) does exactly what its name suggests and processes huge batches of graphic data. You will find that your computer's graphics card has at least one GPU. As opposed to the basic on-board graphic capabilities that PC motherboards supply, dedicated graphics cards interface with the motherboard via an expansion slot to work almost exclusively on graphic rendering. This also means you can upgrade your graphics card if you want to get a bit more performance from your PC. Not only this, but modern GPUs fulfill a broad computational workload beyond just rendering, making them an extension to the central processing unit.
3.3 ( The Components of the System Unit: Expansion Slots)
Expansion slots are sockets on the motherboard where expansion cards can be installed. Common types of expansion cards include graphics, sound, and network cards.
3.1 ( Emerging 5th Generation Computers: Nanotechnology)
Nanotechnology and molecular manufacturing involves the use of nanoscale (extremely small) tools and nonbiological processes to build structures, devices, and systems at the molecular level. It is a technology based on the ability to build structures to complex, atomic specifications by means of mechanosynthesis, or reaction outcomes determined by the use of mechanical constraints. Nanotechnology is a very diverse field, which is having a bigger and bigger impact on the world. It has applications in medicine, cars, spacecraft, food, electronics, and materials science just to name a few.
3.3 ( The Components of the System Unit: Ports)
Ports are sockets that allow cables to be plugged in without opening the system unit. Some examples are serial, parallel, and Universal Serial Bus (USB) ports, which are recognizable by their distinct shapes.
3.1 ( Emerging 5th Generation Computers: Quantum Computing)
Quantum computing is the study of a non-classical model of computation. It is said to be more efficient than modern computing through the use of quantum tunneling. Quantum computers are expected to reduce power consumption from 100 to 1,000 times and will allow computing to surpass any and all limits that traditional computing has set.
3.2 (Introduction to Computer Hardware: RAM)
Random-access memory, or RAM, is hardware found in the memory slots of the motherboard. The role of RAM is to temporarily store information created by programs and to do so in a way that makes this data immediately accessible. The tasks that require random memory could be rendering images for graphic design, editing video or photographs, or multitasking with multiple applications open.
3.2 (Introduction to Computer Hardware: CPU)
The CPU (central processing unit or processor) is responsible for processing all information from programs run by your computer. The speed at which the processor processes information is measured in gigahertz (GHz). This means that a processor advertising a high GHz rating will likely perform faster than a similarly specified processor of the same brand and age.
3.3 ( The Architecture of a Computer System: The Computer System)
The computer system is a system of hardware, software, networking, and human components that function together. The IPOS (input-process-ouput-storage) model explains what computer systems are used for. They take input, process it, and provide an output while using storage to keep intermediate and final results of the transformation of data. Individual hardware components support the function of computer systems.
3.3 ( The Architecture of a Computer System: Basic Components)
Generally, computer hardware contains three major components: the central processing unit, storage, and peripheral devices. The central processing unit supports data processing. Computer memory stores ephemeral programs and data in use temporarily for quick access and primarily store it in RAM. Peripheral devices support the input and output operations of the system. Most computing systems include these elements, which constitute the Von Neumann architecture of a computer system, another name for the IPOS model.
3.2 (Introduction to Computer Hardware: Expansion Card)
In computing, the expansion card, expansion board, adapter card, or accessory card is a printed circuit board that can be inserted into an electrical connector or expansion slot on a computer motherboard, backplane, or riser card to add functionality to a computer system via the expansion bus. An expansion bus is a computer bus that moves information between the internal hardware of a computer system (including the CPU and RAM) and peripheral devices. It is a collection of wires and protocols that allows for the expansion of a computer.
3.3 (Input/Output Devices)
Input devices translate data into a form that the computer can understand, and output devices translate information into a form that humans can understand. The keyboard is the most common input device. Direct input devices such as pointing devices (mouse and trackball) and scanning devices (bar code readers) are much faster and have less room for error compared to the keyboard. Styluses, cameras, and microphones are input devices more commonly used in smartphones. Monitors and printers are the most common output devices. Monitors present the output on a screen, and printers produce hard copies on paper. Other examples of output devices include speakers, 3D printers, and projectors. Identify the I/O devices attached to the system unit of the machine you are using. Consider how each device supports your communication with the computer system.
3.1 (First and Second Generation Computers: Vacuum Tubes)
(1946-1959) ENIAC emerged in 1946 as a 30-ton machine with 18,000 vacuum tubes. When it was first being used, lights dimmed in sections of Philadelphia. The first-generation computers used vacuum tubes for circuitry and magnetic drums for memory, and they were often enormous in size. They consumed a great deal of electricity and were expensive to operate. They often malfunctioned because of the excessive heat they generated. This generation of computers relied on machine languages, the lowest-level programming languages understood by computers. They could run one program at a time and it took a long time, sometimes weeks, to set up a different program. Punched cards were used for input, and the computers printed out the outputs. EDVAC (Electronic Discrete Variable Automatic Computer), UNIVAC (Universal Automatic Computer), IBM-701, and IBM-650 are other notable first-generation computers. Vacuum tubes were the only electronic components available during the first generation of computers and could complete calculations within milliseconds. However, vacuum tubes were large, had limited storage capacity, were unreliable, and required a lot of maintenance.
3.1 (First and Second Generation Computers: Transistors)
(1959-1965) Transistors replaced vacuum tubes in the second generation of computers. Transistors were more reliable and economical. The smaller electronic components in the second generation could maintain two states, "Off" and "On," represented by the binary digits 0 and 1, respectively. Although transistors were invented in 1947, it took almost a decade for them to find their place in computer hardware. Second-generation computers still relied on punched cards for input and printouts for output. Tapes and disks were used for storage purposes. The first computers of this generation were built for the atomic energy industry and included Honeywell 400, IBM 7094, CDC 1604, CDC 3600, and UNIVAC 1108. Over 100 computer programming languages were developed to work with second-generation computers. Machine languages representing instructions in binary (0s and 1s) were replaced by assembly languages that specified instructions using words. High-level programming languages were also developed, such as early versions of FORTRAN (FORmula TRANslation) and COBOL (Common Business-Oriented Language). While these computers were smaller in size, used less energy, and were easier to move, they were used for specific purposes and still required cooling systems and constant maintenance.
3.1 (Third and Fourth Generation Computers: 3rd Gen. Integrated Circuits)
(1965-1971) The invention of integrated circuits enabled the development of computer systems that were cheaper, faster, smaller, and more reliable. Integrated circuits miniaturized transistors and placed them on silicon chips called semiconductors. Users interacted with third-generation computers using keyboards and monitors that communicated with the other components of the hardware and operating systems. Operating systems made it possible for computers to run multiple applications at the same time and to share memory and other resources. The computational time was reduced from milliseconds to nanoseconds. While integrated circuits increased computing power, they were complicated to manufacture, difficult to maintain, and required air conditioning to keep the computers cool enough to run. Examples of third-generation computers include the PDP-8, PDP-11, ICL 2900, IBM 360, and IBM 370.
3.1 (Third and Fourth Generation Computers: 4th Gen. Microprocessors)
(1971-Present) Microprocessors include thousands of integrated circuits on a single silicon chip. They created the fourth generation of computers. This generation of computers is characterized by a significant reduction in processor size and, at the same time, a significant increase in capabilities. The Intel 4004 chip, developed in 1971, included all the components of the computer on a single chip. It powered the Busicom calculator and paved the way for the personal computer. The first IBM computer for home use was available in 1981, followed by Apple's Macintosh computer in 1984. Fourth-generation computers also saw the development of graphical user interfaces, the mouse, and handheld devices. Several operating systems, such as MS-DOS and Microsoft Windows, were developed during this time period. Fourth-generation computers are more reliable than their predecessors, calculate in picoseconds (one trillionth of a second), use high-level languages, and are portable and economical.
3.1 (Computer History and Hardware: Desktop Computers)
A major step in the popularization of computer systems was the development of desktop computers. Steve Jobs and Stephen Wozniak built the first viable home computer and established Apple Computer Inc. (now Apple Inc.) in 1976 to mass-produce their garage-built home computer. Other companies, such as Commodore, offered similar solutions, but these smaller computers were not widely adopted by businesses, which continued to use the well-established mainframe computers. In 1981, IBM introduced its first desktop computer called the personal computer, or PC, whose underlying software was developed by a newly formed company known as Microsoft. The term PC is now widely used to refer to all machines that evolved from IBM's personal computer product, including desktops and laptops. Toward the end of the twentieth century, the ability to connect individual computers in a world-wide system called the internet was revolutionizing communication. The British scientist Tim Bernes-Lee proposed a system by which documents stored on computers throughout the internet could be linked together producing a system of linked information called the World Wide Web. In order to make web pages more accessible to users, search engines (e.g., Bing and Google) and browsers (e.g., Edge and Chrome) were developed. Search engines use technologies to index and tag pages so users can quickly search for resources based on keywords. The miniaturization of computing machines continued. Tiny computers are embedded today in a wide variety of electronic appliances and devices. Because hardware components are continuing to get smaller, the capabilities of smartphones continue to expand. These handheld computers are much more than mobile telephones. They are equipped with a wide variety of sensors, including cameras, microphones, compasses, and touch screens, as well as a number of wireless technologies used to communicate with other smartphones and computers.
3.3 (Types of Computers: Microcomputer)
A microcomputer is more commonly known as a personal computer. It is a general-purpose computer for individual use. It has a memory, storage, input and output units, and a microprocessor as a central processing unit. Desktops, laptops, and handheld or mobile devices are all microcomputers.
3.3 ( The Components of the System Unit: Motherboard)
Again, the motherboard is the main circuit board for the computer containing both soldered components that cannot be removed and sockets or slots for components that can be removed. The motherboard holds the CPU, RAM, and ROM chips, as well as other hardware components. RAM stores instructions and data while they are being used. This storage is volatile, which means when the system is turned off, the contents in RAM are lost. Unlike RAM, ROM chips are nonvolatile memory, keeping their content whether the system is on or off, and generally contain instructions for starting up the computer.
3.3 ( Components of Computer Hardware: Buses)
Buses or bus lines are the wires that serve as electrical roadways, transmitting information between the CPU and other components. The size of the bus is related to the amount of data that can be transmitted at once. Instructions are sent through the bus lines to the CPU and include how to process the data and which component to use. These instructions are split and sent through three different types of buses: address buses, data buses, and control buses.
3.3 (Input/Output Devices: Communication Devices)
Communication devices allow a computer to send and receive data to and from other computers. Modems send information over a phone line or coaxial cable, whereas a network card sends information over dedicated network cables. Satellite, wireless, and Bluetooth technologies enable data to be transmitted without the need for physical wires. Satellite communication uses radio signals and orbiting satellites to receive and send data from one system to another. Bluetooth adapters facilitate wireless communication between electronic devices. Common devices that use Bluetooth include hands-free earpieces, wireless keyboards, mouses, and microphones.
3.2 (Introduction to Computer Hardware: Hardware and History)
Computer hardware includes the physical, tangible parts or components of a computer, such as the monitor, mouse, keyboard, computer data storage, hard disk drive (HDD), graphic cards, sound cards, memory, motherboard, and so on, all of which are objects you can see and touch. In contrast, software is instructions that can be stored and run by the physical hardware. This section will help you understand the inner workings of your computer by introducing you to its basic components.
3.3 (Secondary Storage: Computer Storage and Memory)
Computer storage and memory are often measured in megabytes (MB), gigabytes (GB), and terabytes (TB). A medium-sized novel contains about 1 MB of information. 1 MB is 1,024 kilobytes, or 1,048,576 (1024x1024) bytes, not one million bytes. However, you may find documents that estimate each MB to 1,000 KB. When planning storage requirements, be sure to verify the accuracy of the documented storage capacity. Similarly, 1 gigabyte (GB) is 1,024 MB, 1 terabyte (TB) is 1,024 GB, and 1 petabyte (PB) is 1,024 TB. For another point of reference, 1 TB is roughly equivalent to 1,500 CDs worth of data, and 1 PB of data would create over 1.5 million CDs, a stack a mile high.
3.1 (Computer History and Hardware: The Leibniz Machine)
More sophisticated computing machines emerged between the Middle Ages and the Modern Era when a few inventors began to experiment with the technology of gears. These machines represented data through gear positioning. The data was initially entered by mechanically positioning the gears in a specific gear position. The final gear position represents the output of the calculations. One such machine is the Leibniz machine in which the gears of the machine are initially mechanically set in a position that represents the input, and their final state represents the output of the calculations. As the systems became more complex, they were able to perform more complex operations. The Leibniz machine was designed to perform basic arithmetic operations, and the algorithm for addition was embedded into the structure of the hardware itself. Babbage's Analytical Engine (which was never constructed) was designed to read instructions in the form of holes on paper cards. In other words, Babbage's Analytical Engine was programmable. Ada Lovelace, who published a paper demonstrating that the Analytical Engine is indeed programmable, is considered to be the world's first programmer.
3.3 (Secondary Storage)
Secondary storage devices hold data and information permanently. Secondary storage devices store data and instructions while they are not being used; the saved content remains on the secondary storage unit even when the computer is powered down. There is a variety of secondary storage types, including floppy and hard drives, flash drives, magnetic tape, and optical discs, such as CDs and DVDs. A bit is the smallest unit of storage that is set to 0 or to 1. Bits need to be combined to create a useful representation of data or information; a group of eight bits forms a byte. A byte contains enough information to store a single character, such as the letter "M."
3.3 ( Components of Computer Hardware: Central Processing Unit)
The central processing unit (CPU) is the electronic circuit responsible for executing computer program instructions. The CPU consists of three parts: 1. the arithmetic logic unit (ALU), which contains circuitry that performs operations on data (such as addition and subtraction); 2. the control unit, which contains the circuitry coordinating the machine's activities; and 3. the processor register, which contains data storage cells called registers. Registers are high-speed storage areas in the CPU. All data must be stored in a register before it can be processed. They serve as temporary holding places for data being manipulated by the CPU. Registers hold the inputs to the ALU and store the results. To perform an operation on data stored in the main memory, the control unit transfers the data from the main memory into the registers, informs the ALU which registers hold the data, activates the ALU, and tells the ALU which register should receive the result.
3.1 ( Emerging 5th Generation Computers: Artificial Intelligence)
The fifth generation started in the early 1980s when microprocessor chips were able to accommodate tens of millions of electronic components using ultra-large-scale integration (ULSI). These computers are based on parallel processing (multiple programs running concurrently) and artificial intelligence (AI) software. They support the development of artificial intelligence and natural language processing while using principles of robotics, neural networks, expert systems, and natural language understanding and generation. Quantum computing, molecular technology, and nanotechnology are expected to significantly contribute to the abilities of fifth-generation computers. Fifth-generation computing devices will be able to respond to natural language input and are capable of learning. Emerging technologies may advance computers in unimaginable directions. Research efforts and experiments coupled with emerging technologies provide glimpses into the computers of the future.
3.2 (Introduction to Computer Hardware: Hard Drive)
The hard drive is a storage device responsible for storing permanent and temporary data. This data comes in many different forms but is essentially anything saved or installed to a computer; for example, computer programs, family photos, operating systems, word-processing documents, and so on. There are two different types of storage devices: the traditional hard disk drive (HDD) and the newer solid-state drives (SSD). Hard disk drives work by writing binary data onto spinning magnetic disks called platters that rotate at high speeds, while a solid-state drive stores data by using static flash memory chips.
3.1 (Computer History and Hardware: ENIAC
The idea of communicating instructions with punched cards originated in 1801 in a system specifying the steps of the weaving process. Different patterns of holes resulted in different woven designs. Later, Herman Hollerith used punched cards to speed up the tabulation process in the 1890 U.S. census. Punched cards were heavily used for a variety of computing systems until the mid-1970s. Electronic advances at the beginning of the twentieth century enabled the production of complex hardware. Examples of this progress include the electromechanical machine of George Stibitz completed in 1940 at Bell Laboratories and Mark I completed in 1944 at Harvard University by Howard Aiken and a team of IBM engineers. These machines made heavy use of electronically controlled mechanical relays. Paralleling these efforts, the use of vacuum tubes gave way to fully electronic computers, such as the Atanasoff-Berry machine constructed at Iowa State College between 1937 and 1941 and Colossus built in England to decode German messages during the latter part of World War II. Other more flexible machines, such as ENIAC (Electronic Numerical Integrator and Calculator) developed at Pennsylvania State University, soon followed. From that point on, the development of computer systems largely depended on advancements in technology, such as the invention of the transistor. Later, the invention of complete circuits allowed for the integration of multiple circuits on one piece of semiconductor material, such as silicon. These integrated circuits reduced the size of the early computing systems of the 1940s from room-sized machines to machines the size of a single cabinet. Processing power began to double every two years. The mass production of integrated circuits made computers less expensive and thus more readily available in the market.
3.3 ( Components of Computer Hardware: Random Access Memory)
The memory unit consists of random-access memory (RAM), sometimes referred to as primary or main memory. Unlike a hard drive (permanent memory, secondary memory), this memory is fast and directly accessible by the CPU. Loading data from secondary to primary memory allows the CPU to operate faster. However, RAM is ephemeral, meaning data stored in RAM is lost when the computer is powered off. RAM is split into partitions. Each partition consists of an address and its contents, all in binary form. The address uniquely identifies every location in the memory. In addition to RAM, read-only memory (ROM) is another component that stores instructions for crucial system activities, including booting up the system and initializing different computer components.
3.3 ( The Components of the System Unit: System Clock)
The system clock sends out a pulse of electricity at regular intervals. The electronic components of the computer need these electric pulses in order to operate. The more pulses sent out by the system clock, the faster the computer. One instruction gets processed per pulse. Multiple processing units and a higher clock speed increase the processing speed of the computer system. The system speed commonly is measured in two primary measurements: megahertz (MHz), which converts to millions of pulses per second gigahertz (GHz), which converts to billions of pulses per second
3.3 (The System Unit)
The system unit, also known as a tower or chassis, encases various components already mentioned: the motherboard, CPU, RAM, power supply, and any other internally installed components. The term system unit is often used to differentiate between the computer and its peripheral devices.
3.2 (The Computer System)
You have already learned a bit about the basic components of a computer system, a system of hardware, software, networking, and human components that function together. Now take another look at the diagram introduced earlier in this section. The IPOS (input-process-output-storage) model explains what computer systems are used for. They take input, process it, and provide an output while using storage to keep intermediate and final results of the transformation of data. Individual hardware components support the function of computer systems. Generally, computer hardware contains three major components: the central processing unit, storage, and peripheral devices. The central processing unit supports data processing. Computer memory stores ephemeral programs and data in use temporarily for quick access and primarily stores it in RAM. Peripheral devices support the input and output operations of the system. Most computing systems include these elements, which constitute the Von Neumann architecture of a computer system, another name for the IPOS model.
