What exactly is a PC. Most people immediately answer that PC stands for personal computer, which in fact it does. Many continue by defining a personal computer as any small computer system purchased and used by an individual. Although it is true that all PCs are personal computers, not all personal computers are PCs. For example, all of Apple's pre-2006 Motorola/IBM processor based Macintosh systems, older 8080/Z-80 processor based CP/M machines, and even old Apple system are considered personal computers, but most people wouldn't call them PCs, least of all the Mac users! For the true definition of what a PC is, we must look deeper. Calling something a PC implies that it is something much more specific than just any personal computer. One thing it implies is a family relation to the original IBM PC from 1981. In fact, I'll go so far as to say that IBM literally invented the type of computer we call a PC today; that is, IBM designed and created the very first one, and IBM's definition set all the standards that made the PC distinctive from other personal computers. I'm not saying that IBM invented the personal computer; many recognize the historical origins of the personal computer in the MITS Altair, introduced in 1975, even though other small computers were available prior. However, although IBM did not invent the personal computer, it did invent the type of personal computer that today we call the PC. Some people might take this definition a step further and define a PC as any personal computer that is "IBM compatible." In fact, many years back, PCs were called either IBM compatibles or IBM clones, in essence paying homage to the origins of the PC at IBM.
The reality today is that although IBM clearly designed and created the PC in 1981 and controlled the development and evolution of the PC standard for several years thereafter, IBM is no longer in control of the PC standard; that is, it does not dictate what makes up a PC today. IBM lost control of the PC standard in 1987 when it introduced its PS/2 line of systems. Up until then, other companies that were producing PCs literally copied IBM's systems right down to the chips, connectors, and even the shapes (form factors) of the boards, cases, and power supplies. After 1987, IBM abandoned many of the standards it created in the first place, and the designation "IBM compatible" started to be considered obsolete.
Who Controls PC Hardware?
Although it is clear that Microsoft has always had the majority control over PC software by virtue of its control over the dominant PC operating systems, what about the hardware? It is easy to see that IBM controlled the PC hardware standard up through 1987. After all, IBM invented the core PC motherboard design; the original expansion bus slot architecture (8/16-bit ISA bus); the ROM BIOS interface, serial and parallel port implementations; video card design through VGA and XGA standards; floppy and hard disk interface and controller implementations; power supply designs; keyboard interfaces and designs; the mouse interface; and even the physical shapes (form factors) of everything from the motherboard to the expansion cards, power supplies, and system chassis.
But to me the real question is which company has been responsible for creating and inventing newer and more recent PC hardware designs, interfaces, and standards? When I ask people that question, I normally see some hesitation in their responses-some people say Microsoft (but it controls the software, not the hardware), and some say HP/Compaq or Dell, or they name a few other big-name system manufacturers. Some, however, surmise the correct answer-Intel. I can see why many people don't immediately realize this; I mean, how many people actually own an Intel-brand PC? But a system that was designed and built by or even purchased through, Intel. Believe it or not, many people today do have Intel PCs!
Certainly this does not mean that consumers have purchased their systems from Intel because Intel does not sell complete PCs to end users. You can't currently order a system from Intel, nor can you purchase an Intel-brand system from somebody else. What I am talking about are the major components inside, including especially the motherboard as well as the core of the motherboard-the chipset.
How did Intel come to dominate the interior of our PCs? Intel has been the dominant PC processor supplier since IBM chose the Intel 8088 CPU in the original IBM PC in 1981. By controlling the processor, Intel naturally controlled the chips necessary to integrate its processors into system designs.
This naturally led Intel into the chipset business. It started its chipset business in 1989 with the 82350 Extended Industry Standard Architecture (EISA) chipset, and by 1993 it had become-along with the debut of the Pentium processor-the largest-volume major motherboard chipset supplier. Now I imagine Intel sitting there, thinking that it makes the processor and all the other chips necessary to produce a motherboard, so why not just eliminate the middleman and make the entire motherboard too? The answer to this, and a real turning point in the industry, came about in 1994 when Intel became the largest-volume motherboard manufacturer in the world. By 1997, Intel made more motherboards than the next eight largest motherboard manufacturers.
After the industry downturn in 2001, Intel concentrated on its core competency of chip making, and began using Chinese contract manufacturers such as Foxconn to make Intel-branded motherboards. Since then, contract manufacturers such as Asus, Foxconn, ECS, MSI, and Gigabyte have essentially taken over the market for motherboard manufacturing. Regardless of which company actually manufactures the boards, the main part of any motherboard is the chipset, which contains the majority of the motherboard circuitry. These days about 80% of PCs on the market use Intel processors, and the majority of those are plugged in to motherboards built using Intel chipsets.
Intel controls the PC hardware standard because it controls the PC motherboard and most of the components on it. It not only makes the majority of motherboards being used in systems today, but it also supplies the majority of processors and motherboard chipsets to other motherboard manufacturers.
Intel also has had a hand in setting several recent PC hardware standards, such as the following:
Peripheral Component Interconnect (PCI) local bus interface.
Accelerated Graphics Port (AGP) interface for high-performance video cards.
PCI Express (originally known as 3GIO), the interface selected by the PCI Special Interest Group (PCI SIG) to replace both PCI and AGP as the high-performance bus for newer PCs.
Industry-standard motherboard form factors such as ATX (including variations such as micro ATX and Flex ATX) and BTX (including variations such as micro BTX, nano BTX, and pico BTX). ATX is still the most popular, and beginning in 1996-1997 it replaced the somewhat long-in-the-tooth IBM-designed Baby-AT form factor, which had been used since the early 1980s.
Desktop Management Interface (DMI) for monitoring system hardware functions.
Dynamic Power Management Architecture (DPMA) and Advanced Power Management (APM) standards for managing power use in the PC.
Intel dominates not only the PC, but the entire worldwide semiconductor industry. According to the sales figures compiled by iSuppli, Intel has about one and a half times the sales of the next closest semiconductor company (Samsung) and more than four times the sales of competitor AMD, it is no wonder that a popular industry news website called The Register uses the term Chipzilla when referring to the industry giant.
Whoever controls the operating system controls the software for the PC, and whoever controls the motherboard controls the hardware. Because Microsoft and Intel together seem to control software and hardware in the PC today, it is no surprise the modern PC is often called a "Wintel" system.
Many of the top-selling system manufacturers do design and make their own motherboards, especially for their higher-end systems. According to Computer Reseller News magazine, the top desktop systems manufacturers for the last several years have consistently been names such as HP, Dell, and Lenovo (formerly IBM). These companies design and manufacture their own motherboards as well as purchase existing boards from motherboard manufacturers. In rare cases, they even design their own chips and chipset components for their own boards. Although sales are high for these individual companies, a large segment of the market is what those in the industry call the reseller systems.
Reseller is the term used by the industry to refer to what would otherwise be called generic PCs that is, PCs assembled from a collection of industry-standard, commercially available components. The reseller designation comes from the fact that historically most of the chassis used by this type of system have been white (or ivory or beige). The great thing about reseller systems is that they use industry-standard components that are interchangeable. This interchangeability is the key to future upgrades and repairs because it ensures that a plethora of replacement parts will be available to choose from and will be interchangeable. For many years, I have recommended avoiding proprietary systems and recommended more industry standard reseller systems instead.
Companies selling reseller systems do not usually manufacture the systems; they assemble them. That is, they purchase commercially available motherboards, cases, power supplies, disk drives, peripherals, and so on, and assemble and market everything together as complete systems. Some companies such as HP and Dell manufacture some of their own systems as well as assemble some from industry-standard parts. In particular, the HP Pavilion and Dell Dimension lines are composed largely of mainstream systems made with mostly industry-standard parts. PC makers using mostly industry standard parts also include high-end game system builders such as Voodoo PC (owned by HP) and Alienware (owned by Dell). Other examples include Gateway and eMachines (owned by Gateway), whose PCs are also constructed using primarily industry-standard components. Note that there can be exceptions for all of these systems; for example, I know that some of the Dell Dimension XPS systems use proprietary parts such as power supplies. I recommend avoiding such systems, due to future upgrade and repair hassles.
Others using industry-standard components include Acer, CyberPower, Micro Express, and Systemax, but hundreds more could be listed. In overall total volume, this ends up being the largest segment of the PC marketplace today. What is interesting about reseller systems is that, with very few exceptions, you and I can purchase the same motherboards and other components any of the reseller manufacturers can (although we would probably pay more than they do because of the volume discounts they receive). We can assemble a virtually identical reseller system from scratch ourselves.
PCs can be broken down into many categories. I like to break them down in two ways-by the design and/or width of the processor bus (often called the front side bus, or FSB) as well as by the width of the internal registers, which dictates the type of software that can be run.
When a processor reads data and the data moves into the processor via the processor's external data connection. Traditionally this connection has been a parallel bus; however, in newer chips it is a serialized point-to point link, transferring fewer bits at a time but at a much higher rate. Older designs often had several components sharing the bus, whereas the newer point-to-point links are exclusively between the processor and the chipset.
Processor Data Bus Width Register Size
8088 8-bit 16-bit
8086 16-bit 16-bit
286 16-bit 16-bit
386SX 16-bit 32-bit
386DX/486/5x86 32-bit 32-bit
Intel/AMD x86 w/FSB 64-bit 32-bit
AMD x86 w/HyperTransport 16-bit 32-bit
AMD x86-64 w/HT 16-bit 64-bit
Intel x86-64 w/FSB 64-bit 64-bit
Intel x86-64 w/QPI 20-bit 64-bit
A common confusion arises in discussions of processor "widths." Some people take the width to refer to how many bits of data can be read or written at a time, whereas others refer to the size of the internal registers, which control how much data can be operated on at a time. Although many processors have had matching data bus widths and internal register sizes, they are not always the same, which can lead to more confusion. For example, most Pentium processors have 64-bit data bus widths and yet include internal registers that are only 32 bits wide. The newer AMD and Intel processors with x86-64 architecture have 64-bit internal registers and can run in both 32-bit and 64-bit modes. Thus, from a software point of view, there are PC processors capable of running 16-bit, 32-bit, and 64-bit instructions. For backward compatibility, those having 64-bit registers can also run 32-bit and 16-bit instructions, and those with 32-bit registers can run 16-bit instructions. Whereas the register size dictates what type of software instructions the processor can run, the data bus width is the major factor in motherboard and chipset design because it dictates how many bits move in and out of the chip in one cycle.
A modern PC is both simple and complicated. It is simple in the sense that over the years, many of the components used to construct a system have become integrated with other components into fewer and fewer actual parts. It is complicated in the sense that each part in a modern system performs many more functions than did the same types of parts in older systems.
This section briefly examines all the components and peripherals in a modern PC system. Each item is discussed below.
The motherboard is the core of the system. It really is the PC; everything else is connected to it, and it controls everything in the system.
The processor is often thought of as the "engine" of the computer. It's also called the CPU (central processing unit).
The system memory is often called RAM (for random access memory). This is the primary working memory, which holds all the programs and data the processor is using at a given time.
The case is the frame or chassis that houses the motherboard, power supply, disk drives, adapter cards, and any other physical components in the system.
The power supply feeds electrical power to the internal components in the PC.
The floppy drive is a low-capacity, removable-media, magnetic-storage device. Many recent systems use other types of removable magnetic or USB-based flash memory devices instead of floppy drives for removable storage.
The hard disk is the primary high-capacity storage media for the system.
CD or DVD drive
CD (compact disc) and DVD (digital versatile disc) drives are relatively high-capacity, removable-media, optical drives; most newer systems include drives featuring write/rewrite capability.
The keyboard is the primary device on a PC that is used by a human to communicate with and control a system.
Although many types of pointing devices are on the market today, the first and most popular device for this purpose is the mouse.
The video card controls the information you see on the monitor.
Display/ output units (CRT/LCD)
A sound card enables the PC to generate complex sounds.
Most prebuilt PCs ship with a network interface and possibly a modem.