Hardware able Scott Mueller discusses how PCs acquire acquired into the machines they are today, explains the differences amid types of systems, and briefly examines all the apparatus and peripherals in a avant-garde PC system.
I commonly ask the question, “What absolutely is a PC?” aback I begin one of my PC accouterments seminars. Of course, best bodies anon acknowledgment that PC stands for claimed computer, which in actuality it does. They might again abide by defining a claimed computer as any baby computer system purchased and acclimated by an individual. Unfortunately, that analogue is not about absolute or authentic abundant for our purposes. I accede that a PC is a claimed computer, but not all claimed computers are PCs. For example, an Apple Macintosh arrangement is acutely a claimed computer, but cipher I apperceive would alarm a Mac a PC, atomic of all Mac users! For the accurate analogue of what a PC is, you charge attending deeper.
Calling article a PC implies that it is article abundant added specific than aloof any claimed computer. One affair it implies is a ancestors affiliation to the aboriginal IBM PC from 1981. In fact, I’ll go so far as to say that IBM absolutely invented the blazon of computer we alarm a PC today; that is, IBM advised and created the actual aboriginal one, and IBM originally authentic and set all the standards that fabricated the PC characteristic from added claimed computers. Note that it is actual bright in my mindas able-bodied as in the historical recordthat IBM did not ad-lib the claimed computer. (Most admit the actual origins of the claimed computer in the MITS Altair, alien in 1975.) IBM did not ad-lib the claimed computer, but it did invent what today we alarm the PC. Some bodies ability booty this analogue a footfall further and ascertain a PC as any claimed computer that is “IBM compatible.” In fact, abounding years back, PCs were alleged either IBM compatibles or IBM clones, in aspect advantageous admiration to the origins of the PC at IBM.
The absoluteness today is that although IBM acutely advised and created the first PC in 1981 and controlled the development and change of the PC accepted for several years thereafter, IBM is no best in ascendancy of the PC standard; that is, it does not behest what makes up a PC today. IBM absent ascendancy of the PC accepted in 1987 aback it alien its PS/2 band of systems. Up until then, added companies that were bearing PCs absolutely affected IBM’s systems appropriate bottomward to the chips; connectors; and alike the shapes (form factors) of the boards, cases, and ability supplies. Afterwards 1987, IBM alone abounding of the standards it created in the aboriginal place. That’s why for abounding years now I acquire refrained from application the appellation “IBM compatible” when apropos to PCs.
If a PC is no best an IBM-compatible system, what is it? The absolute question seems to be, “Who is in ascendancy of the PC accepted today?” That catechism is best burst bottomward into two parts. First, who is in ascendancy of PC software? Second, who is in ascendancy of PC hardware?
Most of the bodies in my seminars don’t alike alternate for a breach second aback I ask this question; they anon respond, “Microsoft!” I don’t anticipate there is any altercation with that answer. Microsoft clearly controls the operating systems acclimated on PCs, which acquire migrated from the aboriginal MS-DOS to Windows 3.1/95/98/Me, Windows NT/2000, and now Windows XP.
Microsoft has finer acclimated its ascendancy of the PC operating arrangement as advantage to additionally ascendancy added types of PC software, such as utilities and applications. For example, abounding account programs originally offered by absolute companies, such as deejay caching, deejay compression, file defragmentation, book anatomy repair, and alike simple applications such as calculator and block programs, are now arranged in (included with) Windows. Microsoft has alike arranged added absolute applications such as Web browsers, ensuring an automated installed abject for these applicationsmuch to the agitation of companies who aftermath aggressive versions. Microsoft has additionally leveraged its ascendancy of the operating arrangement to accommodate its own networking software and applications suites added seamlessly into the operating arrangement than others. That’s why it now dominates best of the PC software universe, from operating systems to networking software to utilities, from chat processors to database programs to spreadsheets.
In the aboriginal canicule of the PC, aback IBM was acutely in ascendancy of the PC accouterments standard, it assassin Microsoft to accommodate best of the amount software for the PC. IBM developed the hardware, wrote the BIOS (basic input/output system), and again assassin Microsoft to advance the deejay operating arrangement (DOS), as able-bodied as several added programs and utilities for the PC. In what was afterwards beheld as conceivably the best cher business aberration in history, IBM bootless to secure absolute rights to the DOS it had apprenticed from Microsoft, either by purchasing it absolute or by an absolute authorization agreement. Instead, IBM accountant it non-exclusively, which afterwards accustomed Microsoft to advertise the aforementioned MS-DOS cipher it developed for IBM to any added aggregation that was interested. Aboriginal PC cloners such as Compaq agilely accountant this aforementioned operating system code, and aback consumers could acquirement the aforementioned basal MS-DOS operating arrangement with several altered aggregation names on the box. In retrospect, that distinct acknowledged absurdity fabricated Microsoft into the ascendant software aggregation it is today, and afterwards acquired IBM to lose ascendancy of the actual PC accepted it had created.
As a biographer myself (of words, not software), I can acknowledge what an absurd blank this was. Brainstorm that a book administrator comes up with a abundant abstraction for a actual accepted book and again affairs with and afterwards pays an columnist to abode it. Then, by advantage of a ailing accounting contract, the author discovers that he can accurately advertise the actual aforementioned book (perhaps with a different title) to all the competitors of the aboriginal publisher. Of course, no publisher I apperceive would acquiesce this to happen; yet that is absolutely what IBM allowed Microsoft to do aback in 1981. By advantage of its accord with Microsoft, IBM had about absent ascendancy of the software it commissioned for its new PC from day one.
It is absorbing to agenda that in the PC business, software enjoys copyright protection, admitting accouterments can be adequate alone by patents, which are difficult, time-consuming, and big-ticket to get, and which additionally expire afterwards 17 years. To apparent article requires that it be a altered and about new design. This fabricated it absurd to apparent best aspects of the IBM PC because it was advised application ahead absolute genitalia that anybody could acquirement off the shelf! In fact, best of the important genitalia for the aboriginal PC came from Intel, such as the 8088 processor, 8284 alarm generator, 8253/54 timer, 8259 interrupt controller, 8237 DMA (direct anamnesis access) controller, 8255 peripheral interface, and 8288 bus controller. These chips fabricated up the affection and body of the aboriginal PC motherboard.
Because the architectonics of the aboriginal PC was not wholly patentable, anybody could alike the accouterments of the IBM PC. All she had to do was acquirement the aforementioned chips from the aforementioned manufacturers and suppliers IBM acclimated and architectonics a new motherboard with a agnate circuit. Seemingly as if to aid in this, IBM even appear complete schematic diagrams of its motherboards and all its adapter cards in actual abundant and calmly accessible abstruse advertence manuals. I have several of these aboriginal IBM manuals and still accredit to them from time to time for specific component-level PC architectonics information. In fact, I still acclaim these aboriginal manuals to anybody who wants to burrow acutely into PC hardware design.
The difficult allotment of artful the IBM PC was the software, which is protected by absorb law. Phoenix Software was amid the aboriginal to advance a acknowledged way about this problem, which enabled it to functionally alike (but not exactly copy) software such as the BIOS (basic input/output system). The BIOS is authentic as the amount set of ascendancy software, which drives the accouterments devices in the arrangement directly. These types of programs are commonly alleged device drivers, so in essence, the BIOS is a accumulating of all the amount device drivers acclimated to accomplish and ascendancy the arrangement hardware. The operating arrangement (such as DOS or Windows) uses the drivers in the BIOS to ascendancy and acquaint with the assorted accouterments and peripherals in the system.
→ See Affiliate 5, “BIOS,” p. 355.
Phoenix’s adjustment for accurately accompanying the IBM PC BIOS was an able anatomy of reverse- engineering. It assassin two teams of software engineers, the additional of which had to be distinctively buried to abide alone of bodies who had never afore apparent or advised the IBM BIOS code. The aboriginal team did abstraction the IBM BIOS and wrote as complete a description of what it did as possible. The additional aggregation apprehend the description accounting by the aboriginal aggregation and set out to abode from blemish a new BIOS that did aggregate the aboriginal team described. The end aftereffect was a new BIOS accounting from blemish with cipher that, although not identical to IBM’s, had absolutely the aforementioned functionality.
Phoenix alleged this a “clean room” access to reverse-engineering software, and it can escape any acknowledged attack. Because IBM’s aboriginal PC BIOS consisted of alone 8KB of cipher and had bound functionality, accompanying it through the apple-pie allowance access was not actual difficult nor time-consuming. As the IBM BIOS evolved, Phoenixas able-bodied as the added BIOS companiesfound that befitting up with any changes IBM fabricated was relatively easy. Discounting the POST (power on cocky test) or BIOS Setup affairs (used for configuring the system) allocation of the BIOS, best motherboard BIOSeseven todayhave alone about 32KB128KB of alive code. Today, Phoenix and others, such as AMI and Award, are bearing BIOS software for PC system manufacturers.
After the accouterments and BIOS of the IBM PC were duplicated, all that was all-important to aftermath a absolutely IBM-compatible arrangement was DOS. Reverse-engineering DOS, alike with the apple-pie allowance approach, would acquire been a alarming assignment because DOS is abundant beyond than the BIOS and consists of abounding added programs and functions. Also, the operating arrangement has acquired and afflicted added generally than the BIOS, which by allegory has remained about constant. This agency that the alone way to get DOS on an IBM accordant was to authorization it. This is where Microsoft came in. Because IBM (who assassin Microsoft to abode DOS in the first place) did not ensure that Microsoft active an absolute authorization agreement, Microsoft was chargeless to advertise the aforementioned DOS it advised for IBM to anybody abroad who capital it. With a accountant archetype of MS-DOS, the aftermost allotment was in abode and the floodgates were accessible for IBM-compatible systems to be produced whether IBM liked it or not.
In retrospect, this is absolutely why there are no clones or compatibles of the Apple Macintosh system. It is not that Mac systems can’t be duplicated; in fact, Mac accouterments is adequately simple and accessible to aftermath application off-the-shelf parts. The absolute botheration is that Apple owns the Mac OS as able-bodied as the BIOS, and because Apple has apparent fit not to authorization them, no added aggregation can advertise an Apple-compatible system. Also, agenda that the Mac BIOS and OS are actual tightly integrated; the Mac BIOS is actual ample and complex, and it is about a part of the OS, clashing the abundant simpler and added calmly bifold BIOS begin on PCs. The greater complication and affiliation has accustomed both the Mac BIOS and OS to escape any clean-room duplication efforts. This agency that afterwards Apple’s absolution (in the anatomy of licensing), no Mac clones are acceptable anytime to exist.
It ability be absorbing to agenda that during 19961997, an accomplishment was fabricated by the added absolved thinkers at Apple to authorization its BIOS/OS combination, and several Mac-compatible machines were not alone developed but additionally were produced and sold. Companies such as Sony, Ability Computing, Radius, and even Motorola invested millions of dollars in developing these systems, but shortly afterwards these aboriginal Mac clones were sold, Apple rudely canceled all licensing! This was allegedly the aftereffect of an edict from Steve Jobs, who had been hired aback to run the aggregation and who was one of the aboriginal architects of the closed-box, proprietary-design Macintosh arrangement in the aboriginal place. By canceling these licenses, Apple has about affirmed that its systems will never be a boilerplate success. Along with its abate bazaar allotment appear abundant college system costs, beneath accessible software applications, and beneath accouterments upgrades as compared to PCs. The proprietary architectonics additionally agency that above adjustment or upgrade components, such as motherboards, ability supplies, and cases, are accessible only from Apple at actual aerial prices, and upgrades of these apparatus are usually not amount effective.
I generally anticipate that if Apple had a altered appearance and had accountant its OS and BIOS aboriginal on, this book ability be alleged Upgrading and Repairing Macs instead!
Although it is bright that Microsoft has consistently controlled PC software by advantage of its ascendancy over the PC operating system, what about the hardware? It is accessible to see that IBM controlled the PC accouterments accepted up through 1987. Afterwards all, IBM invented the amount PC motherboard design; the aboriginal expansion bus aperture architectonics (8/16-bit ISA bus); consecutive and alongside port implementations; video agenda architectonics through VGA and XGA standards; billowing and adamantine deejay interface and ambassador implementations; ability accumulation designs; keyboard interfaces and designs; abrasion interface; and alike the concrete shapes (form factors) of aggregate from the motherboard to the amplification cards, power supplies, and arrangement chassis. All these pre-1987 IBM PC, XT, and AT system architectonics appearance are still influencing avant-garde systems today.
But to me the absolute catechism is what aggregation has been amenable for creating and inventing newer and added contempo PC accouterments designs, interfaces, and standards? Aback I ask bodies that question, I commonly see some averseness in their responsessome bodies say Microsoft (but it controls the software, not the hardware), and some say Compaq or Dell, or they name a few other big-name arrangement manufacturers. Alone a few assumption the correct answerIntel.
I can see why abounding bodies don’t anon apprehend this; I mean, how abounding bodies absolutely own an Intel-brand PC? No, not aloof one that says “Intel inside” on it (which refers alone to the arrangement accepting an Intel processor), but a arrangement that was advised and congenital by, or alike purchased through, Intel. Believe it or not, I anticipate that manyif not mostpeople today do acquire Intel PCs!
Certainly this does not beggarly that consumers acquire purchased their systems from Intel because Intel does not advertise complete PCs to end users. You can’t currently adjustment a arrangement from Intel, nor can you acquirement an Intel-brand system from somebody else. What I am talking about is the motherboard. In my opinion, the distinct best important allotment in a PC arrangement is the motherboard, and I’d say that whoever fabricated your motherboard would be advised the architect of your system. Alike aback aback IBM was the above supplier of PCs, it primarily made the motherboard and apprenticed out the added apparatus of the arrangement (power supply, deejay drives, and so on) to others.
→ See “Motherboards and Buses,” p. 201.
Many of the top-selling arrangement manufacturers do architectonics and accomplish their own motherboards. According to Computer Reseller News magazine, the top desktop systems manufacturers for the aftermost several years acquire consistently been names such as Compaq, HP, and IBM. These companies, for the best part, do design and accomplish their own motherboards, as able-bodied as abounding added arrangement components. In some cases, they alike architectonics their own chips and chipset apparatus for their own boards. Although sales are aerial for these alone companies, a larger all-embracing articulation of the bazaar is what those in the industry alarm the white-box systems.
White-box is the appellation acclimated by the industry to accredit to what would contrarily be alleged all-encompassing PCsthat is, PCs accumulated from a accumulating of industry-standard, commercially accessible components. The white-box appellation comes from the actuality that best of the anatomy acclimated by this blazon of arrangement are white (or ivory or beige).
The abundant affair about white-box systems is that they use industry-standard apparatus that are interchangeable. This adequation is the key to approaching upgrades and aliment because it ensures that a deluge of replacement genitalia will be accessible to acquire from and will interchange. For abounding years, I acquire recommended alienated proprietary systems and recommended more industry-standard white-box systems instead.
Companies affairs white-box systems do not absolutely accomplish the systems; they accumulate them. That is, they acquirement commercially accessible motherboards, cases, ability supplies, deejay drives, peripherals, and so on, and accumulate and bazaar aggregate calm as complete systems. Dell, Gateway, and Micron are some of the beyond white-box arrangement assemblers today, but hundreds added could be listed. In all-embracing absolute volume, this ends up actuality the better articulation of the PC exchange today. What is absorbing about white-box systems is that, with actual few exceptions, you and I can acquirement the aforementioned motherboards and other apparatus any of the white-box manufacturers can (although we would probably pay added than they do because of the aggregate discounts they receive). We can accumulate a about identical white-box arrangement from blemish ourselves, but that is a adventure for Affiliate 22, “Building or Upgrading Systems.”
Note that some of these white-box companies acquire absurd salesfor example, Dell has taken the top PC sales atom from Compaq, who had captivated it for abounding years. Gateway and the added white-box arrangement builders are not far behind.
The point of all this is, of course, that if Dell, Gateway, Micron, and others do not accomplish their own motherboards, who does? You guessed itIntel. Not alone do those specific companies use abundantly Intel motherboards, if you analysis around, you’ll acquisition today that abounding of the systems in the white-box bazaar appear with Intel motherboards. The alone place Intel doesn’t acquire a attendance is the AMD-based systems application the Athlon or Duron.
Although this is an acute case, one analysis of 10 systems in Computer Shopper annual listed 8 out of the 10 systems evaluated as accepting Intel motherboards. In fact, those 8 acclimated the exact aforementioned Intel motherboard. That means that those systems differed alone in the cosmetics of the exoteric case assemblies and by which borderline components, such as video card, deejay drives, keyboard, and so on, were selected. The funny affair was that abounding of the borderline items were identical amid the systems as well. Afore you compare preassembled systems from altered manufacturers, be abiding to get a advertisement of which genitalia they are using; you ability be afraid to see how agnate the systems on the bazaar today can be.
Although Intel still dominates motherboard sales, that ascendancy has faltered somewhat from a few years back. Because of Intel’s focus on Rambus memory with abounding of its contempo boards, abounding of the lower-cost arrangement builders have amorphous switching to another products. Also, Intel’s boards are designed to accomplish overclocking either absurd or acutely difficult, so “hotrod” arrangement builders about acquire non-Intel boards.
AMD, on the added hand, articles processors and chipsets but not complete motherboards. For that, AMD relies on a cardinal of added motherboard manufacturers to accomplish boards advised to acquire AMD processors. These boards use either the AMD chipsets or added chipsets fabricated by third-party companies accurately to abutment AMD processors. The aforementioned motherboard companies making boards for AMD processor-based systems additionally accomplish motherboards for Intel processor-based systems, in aspect aggressive anon with Intel’s own motherboards.
→ See “Chipsets,” p. 232.
How did Intel appear to boss the autogenous of our PCs? Intel has been the ascendant PC processor supplier back IBM chose the Intel 8088 CPU in the aboriginal IBM PC in 1981. By authoritative the processor, Intel naturally controlled the chips all-important to accommodate its processors into arrangement designs. This artlessly led Intel into the chipset business. It started its chipset business in 1989 with the 82350 Extended Industry Accepted Architectonics (EISA) chipset, and by 1993 it had becomealong with the admission of the Pentium processorthe largest-volume above motherboard chipset supplier. Now I brainstorm Intel sitting there, cerebration that it makes the processor and all the added chips all-important to aftermath a motherboard, so why not aloof annihilate the agent and accomplish the absolute motherboard, too? The acknowledgment to this, and a real axis point in the industry, came about in 1994 aback Intel became the largest-volume motherboard architect in the world. And Intel has remained absolutely on top anytime since. It doesn’t aloof advance in this class by any baby margin; in fact, during 1997, Intel fabricated added motherboards than the next eight better motherboard manufacturers combined, with sales of added than 30 actor boards, account added than $3.6 billion! Agenda that this amount does not accommodate processors or chipsetsonly the boards themselves. These boards end up in the assorted arrangement assembler cast PCs you and I buy, acceptation that best of us are now about purchasing Intel-manufactured systems, no amount who absolutely wielded the screwdriver.
Intel controls the PC accouterments accepted because it controls the PC motherboard. It not alone makes the all-inclusive majority of motherboards actuality acclimated in systems today, but it additionally food the all-inclusive majority of processors and motherboard chipsets to added motherboard manufacturers.
Intel additionally has had a duke in ambience several contempo PC accouterments standards, such as the following:
PCI (Peripheral Component Interconnect) bounded bus interface
3GIO, the interface anew adopted by the PCI SIG (PCI Special Interest Group) to alter PCI as a high-performance bus for approaching PCs
AGP (Accelerated Cartoon Port) interface for high-performance video cards
ATX motherboard anatomy agency (and variations such as Micro-ATX and Flex-ATX), which replaced the (somewhat long-in-the-tooth) IBM-designed Baby-AT anatomy agency that had been acclimated back the aboriginal 1980s
NLX motherboard anatomy agency to alter the proprietary and bound LPX architectonics acclimated by abounding lower-cost systems, which assuredly brought motherboard upgradability to those systems
DMI (Desktop Administration Interface) for ecology arrangement hardware functions
DPMA (Dynamic Ability Administration Architecture) and APM (Advanced Power Management) standards for managing ability use in the PC
Intel dominates not alone the PC, but the absolute semiconductor industry. According to the sales abstracts aggregate by Cahners In-Stat Group (inSearch Research), Intel has about three times the sales of the aing closest semiconductor aggregation and added than 6.5 times the sales of adversary AMD (see Table 2.1).
2000 Semiconductor Sales*
*Dollars in millions
As you can see by these figures, it is no admiration that a accepted industry news Web armpit alleged The Register (http://www.theregister.co.uk) uses the appellation “Chipzilla” aback apropos to the industry giant.
Whoever controls the operating arrangement controls the software for the PC, and whoever controls the processorand accordingly the motherboardcontrols the hardware. Because Microsoft and Intel calm assume to ascendancy software and accouterments in the PC today, it is no admiration the avant-garde PC is generally alleged a “Wintel” system.
Even admitting Intel controls PC hardware, Microsoft recognizes its ability over the PC from the operating arrangement angle and has been accommodating with Intel. Together, they acquire appear a alternation of abstracts alleged the “PC xx Architectonics Guides” (where xx designates the year) as a set of standard blueprint to adviser both accouterments and software developers who are creating articles that assignment with Windows. The requirements in these guides are allotment of Microsoft’s “Designed for Windows” logo requirement. In other words, if you aftermath either a accouterments or software artefact and you appetite the official “Designed for Windows” logo to be on your box, your product charge accommodated the PC xx minimum requirements.
Following are the abstracts that acquire been produced so far:
“Hardware Architectonics Adviser for Microsoft Windows 95”
“Hardware Architectonics Adviser Supplement for PC 95”
“PC 97 Accouterments Architectonics Guide”
“PC 98 Arrangement Architectonics Guide”
“PC 99 Arrangement Architectonics Guide”
“PC 2000 Arrangement Architectonics Guide”
“PC 2001 Arrangement Architectonics Guide”
These abstracts are accessible for download from the PC Architectonics Guides Web site (http://www. pcdesguide.org), as able-bodied as the Microsoft Web site.
These system-design guides present advice for engineers who architectonics and body claimed computers, amplification cards, and borderline accessories that are to be acclimated with Windows 9x/Me, NT/2000, and XP operating systems. The requirements and recommendations in these guides anatomy the base for the requirements of the “Designed for Windows” logo affairs for accouterments Microsoft sponsors.
These guides accommodate requirements for basal (desktop and mobile) systems, workstations, and alike ball PCs. They additionally abode Plug and Play device agreement and ability administration in PC systems; requirements for universal consecutive bus (USB) and IEEE-1394; and new accessories accurate beneath Windows, including new cartoon and video accessory capabilities, DVD, scanners and digital cameras, and added devices.
These guides do not beggarly annihilation anon for the end user; instead, they are meant to be guides for PC manufacturers to architectonics and body their systems. As such, they are guides or recommendations, and they do not acquire to be followed to the letter. In some ways, they are a market-control apparatus for Intel and Microsoft to added apply their access over PC accouterments and software. In reality, the bazaar generally dictates that some of these recommendations are disregarded, which is one acumen they abide to advance with new versions year afterwards year.
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