146-433: " IBM PC–compatible " refers to a class of computers that are technically compatible with the 1981 IBM PC and subsequent XT and AT models from computer giant IBM . Like the original IBM PC, they use an Intel x86 central processing unit and are capable of using interchangeable commodity hardware , such as expansion cards . Initially such computers were referred to as PC clones , IBM clones or IBM PC clones , but
292-534: A 32-bit operating system released during the 2000s can still operate many of the simpler programs written for the OS of the early 1980s without needing an emulator , though an emulator like DOSBox now has near-native functionality at full speed (and is necessary for certain games which may run too fast on modern processors). Additionally, many modern PCs can still run DOS directly, although special options such as USB legacy mode and SATA-to-PATA emulation may need to be set in
438-471: A 64-bit UEFI firmware implementation can load only a 64-bit operating system (OS) boot loader or kernel (unless the CSM-based legacy boot is used) and the same applies to 32-bit. After the system transitions from boot services to runtime services , the operating system kernel takes over. At this point, the kernel can change processor modes if it desires, but this bars usage of the runtime services (unless
584-557: A ISA-independent device driver stored in non-volatile memory as EFI byte code or EBC . System firmware has an interpreter for EBC images. In that sense, EBC is analogous to Open Firmware , the ISA-independent firmware used in PowerPC -based Apple Macintosh and Sun Microsystems SPARC computers, among others. Some architecture-specific (non-EFI Byte Code) EFI drivers for some device types can have interfaces for use by
730-725: A UGA (Universal Graphic Adapter) protocol as a way to support graphics features. UEFI did not include UGA and replaced it with GOP (Graphics Output Protocol) . UEFI 2.1 defined a "Human Interface Infrastructure" (HII) to manage user input, localized strings, fonts, and forms (in the HTML sense). These enable original equipment manufacturers (OEMs) or independent BIOS vendors (IBVs) to design graphical interfaces for pre-boot configuration. UEFI uses UTF-16 to encode strings by default. Most early UEFI firmware implementations were console-based. Today many UEFI firmware implementations are GUI-based. An EFI system partition, often abbreviated to ESP,
876-758: A commercial venture. Experience had shown that even if an operating system was technically superior to Windows, it would be a failure in the market ( BeOS and OS/2 for example). In 1989, Steve Jobs said of his new NeXT system, "It will either be the last new hardware platform to succeed, or the first to fail." Four years later in 1993, NeXT announced it was ending production of the NeXTcube and porting NeXTSTEP to Intel processors. Very early on in PC history, some companies introduced their own XT-compatible chipsets . For example, Chips and Technologies introduced their 82C100 XT Controller which integrated and replaced six of
1022-490: A computer capable of running programs that are managed by MS-DOS". The main reason why an IBM standard is not worrying is that it can help competition to flourish. IBM will soon be as much a prisoner of its standards as its competitors are. Once enough IBM machines have been bought, IBM cannot make sudden changes in their basic design; what might be useful for shedding competitors would shake off even more customers. In February 1984 Byte wrote that "IBM's burgeoning influence in
1168-420: A computer through retail channels rather than directly to customers. Because IBM did not have retail experience, they partnered with the retail chains ComputerLand and Sears , who provided important knowledge of the marketplace and became the main outlets for the PC. More than 190 ComputerLand stores already existed, while Sears was in the process of creating a handful of in-store computer centers for sale of
1314-558: A consumer PC manufacturer during April 2005, when it sold its laptop and desktop PC divisions ( ThinkPad / ThinkCentre ) to Lenovo for US$ 1.75 billion . As of October 2007, Hewlett-Packard and Dell had the largest shares of the PC market in North America. They were also successful overseas, with Acer , Lenovo , and Toshiba also notable. Worldwide, a huge number of PCs are " white box " systems assembled by myriad local systems builders. Despite advances of computer technology,
1460-442: A dedicated power supply and included a hard drive. Although official hard drive support did not exist, the third party market did provide early hard drives that connected to the floppy disk controller , but required a patched version of PC DOS to support the larger disk sizes. The only option for human interface provided in the base PC was the built-in keyboard port, meant to connect to the included Model F keyboard. The Model F
1606-531: A few percentage points of market share was Apple Inc. 's Macintosh . The Mac started out billed as "the computer for the rest of us", but high prices and closed architecture drove the Macintosh into an education and desktop publishing niche, from which it only emerged in the mid-2000s. By the mid-1990s the Mac's market share had dwindled to around 5% and introducing a new rival operating system had become too risky
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#17327719759681752-583: A hard drive, the motherboard did not support BIOS expansion ROMs which was needed to support a hard drive controller, and both PC DOS and the BIOS had no support for hard disks. After the XT was released, IBM altered the design of the 5150 to add most of these capabilities, except for the upgraded power supply. At this point adding a hard drive was possible, but required the purchase of the IBM 5161 Expansion Unit, which contained
1898-567: A library of common functions that all software can use for many purposes, such as video output, keyboard input, disk access, interrupt handling, testing memory, and other functions. IBM shipped three versions of the BIOS throughout the PC's lifespan. While most home computers had built-in video output hardware, IBM took the unusual approach of offering two different graphics options, the MDA and CGA cards. The former provided high-resolution monochrome text, but could not display anything except text, while
2044-608: A maximum disk and partition size of 8 ZiB (8 × 2 bytes) . Support for GPT in Linux is enabled by turning on the option CONFIG_EFI_PARTITION (EFI GUID Partition Support) during kernel configuration. This option allows Linux to recognize and use GPT disks after the system firmware passes control over the system to Linux. For reverse compatibility, Linux can use GPT disks in BIOS-based systems for both data storage and booting, as both GRUB 2 and Linux are GPT-aware. Such
2190-401: A maximum of 64 KB onboard, and the more common 64 KB revision to a maximum of 256 KB on the motherboard. RAM cards could upgrade either variant further, for a total of 640 KB conventional memory , and possibly several megabytes of expanded memory beyond that, though on PC/XT-class machines, the latter was a very expensive third-party hardware option only available later in
2336-503: A minor player with its own technology". The Economist predicted in 1983 that "IBM will soon be as much a prisoner of its standards as its competitors are", because "Once enough IBM machines have been bought, IBM cannot make sudden changes in their basic design; what might be useful for shedding competitors would shake off even more customers". After the Compaq Deskpro 386 became the first 80386-based PC, PC wrote that owners of
2482-657: A mouse.) Connectivity to other computers and peripherals was initially provided through serial and parallel ports. IBM provided a serial card based on an 8250 UART . The BIOS supports up to two serial ports. IBM provided two different options for connecting Centronics-compatible parallel printers. One was the IBM Printer Adapter, and the other was integrated into the MDA as the IBM Monochrome Display and Printer Adapter. The expansion capability of
2628-467: A personal computer, possibly a miniaturized version of the IBM System/370 , and Matsushita acknowledged publicly that it had discussed with IBM the possibility of manufacturing a personal computer in partnership, although this project was abandoned. The public responded to these rumors with skepticism, owing to IBM's tendency towards slow-moving, bureaucratic business practices tailored towards
2774-505: A policy of strict secrecy, with all other IBM divisions kept in the dark about the project. Several CPUs were considered, including the Texas Instruments TMS9900 , Motorola 68000 and Intel 8088 . The 68000 was considered the best choice, but was not production-ready like the others. The IBM 801 RISC processor was also considered, since it was considerably more powerful than the other options, but rejected due to
2920-421: A range of machines from different vendors that had widely varying hardware. Those customers who needed other applications than the starter programs could reasonably expect publishers to offer their products for a variety of computers, on suitable media for each. Microsoft's competing OS was intended initially to operate on a similar varied spectrum of hardware, although all based on the 8086 processor. Thus, MS-DOS
3066-657: A rapidly changing market. The idea of acquiring Atari was considered but rejected in favor of a proposal by Lowe that by forming an independent internal working group and abandoning all traditional IBM methods, a design could be delivered within a year and a prototype within 30 days. The prototype worked poorly but was presented with a detailed business plan which proposed that the new computer have an open architecture , use non-proprietary components and software, and be sold through retail stores, all contrary to IBM practice. It also estimated sales of 220,000 computers over three years, more than IBM's entire installed base . This swayed
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#17327719759683212-595: A separate monochrome monitor for text menus. Third parties went on to provide an enormous variety of aftermarket graphics adapters, such as the Hercules Graphics Card . The software and hardware of the PC, at release, was designed around a single 8-bit adaptation of the ASCII character set, now known as code page 437 . The two bays in the front of the machine could be populated with one or two 5.25″ floppy disk drives, storing 160 KB per disk side for
3358-579: A set of UEFI interfaces as defined in the Embedded Base Boot Requirements ( EBBR ) suitable for embedded environments such as Yocto. Many Linux and BSD distros can support both recipes. In December 2018, Microsoft announced Project Mu, a fork of TianoCore EDK II used in Microsoft Surface and Hyper-V products. The project promotes the idea of firmware as a service . The latest UEFI specification, version 2.10,
3504-450: A setup is usually referred to as BIOS-GPT . As GPT incorporates the protective MBR, a BIOS-based computer can boot from a GPT disk using a GPT-aware boot loader stored in the protective MBR's bootstrap code area . In the case of GRUB, such a configuration requires a BIOS boot partition for GRUB to embed its second-stage code due to absence of the post-MBR gap in GPT partitioned disks (which
3650-569: A specific version of the FAT file system , which is maintained as part of the UEFI specification and independently from the original FAT specification, encompassing the FAT32 , FAT16 and FAT12 file systems. The ESP also provides space for a boot sector as part of the backward BIOS compatibility. Unlike the legacy PC BIOS, UEFI does not rely on boot sectors , defining instead a boot manager as part of
3796-459: A total of 320 KB of storage on one disk. The floppy drives require a controller card inserted in an expansion slot, and connect with a single ribbon cable with two edge connectors. The IBM floppy controller card provides an external 37-pin D-sub connector for attachment of an external disk drive, although IBM did not offer one for purchase until 1986. As was common for home computers of the era,
3942-572: A user interface to allow the selection of another UEFI application to run. Utilities like the UEFI Shell are also UEFI applications. EFI defines protocols as a set of software interfaces used for communication between two binary modules. All EFI drivers must provide services to others via protocols. The EFI Protocols are similar to the BIOS interrupt calls . In addition to standard instruction set architecture -specific device drivers, EFI provides for
4088-403: A year. By 1984, IBM's revenue from the PC market was $ 4 billion, more than twice that of Apple. A 1983 study of corporate customers found that two thirds of large customers standardizing on one computer chose the PC, while only 9% chose Apple. A 1985 Fortune survey found that 56% of American companies with personal computers used PCs while 16% used Apple. Almost as soon as the PC reached
4234-418: Is a data storage device partition that is used in computers adhering to the UEFI specification. Accessed by the UEFI firmware when a computer is powered up, it stores UEFI applications and the files these applications need to run, including operating system boot loaders . Supported partition table schemes include MBR and GPT , as well as El Torito volumes on optical discs. For use on ESPs, UEFI defines
4380-545: Is a specification for the firmware architecture of a computing platform . When a computer is powered on , the UEFI-implementation is typically the first that runs, before starting the operating system . Examples include AMI Aptio , Phoenix SecureCore , TianoCore EDK II , InsydeH2O . UEFI replaces the BIOS which was present in the boot ROM of all personal computers that are IBM PC compatible , although it can provide backwards compatibility with
4526-634: Is a legacy of that period; other non-clone machines, while subject to a limit, could exceed 640 KB. Rumors of "lookalike," compatible computers, created without IBM's approval, began almost immediately after the IBM PC's release. InfoWorld wrote on the first anniversary of the IBM PC that The dark side of an open system is its imitators. If the specs are clear enough for you to design peripherals, they are clear enough for you to design imitations. Apple ... has patents on two important components of its systems ... IBM, which reportedly has no special patents on
IBM PC–compatible - Misplaced Pages Continue
4672-466: Is becoming a misnomer, as Intel has lost absolute control over the direction of x86 hardware development with AMD 's AMD64 . Additionally, non-Windows operating systems like macOS and Linux have established a presence on the x86 architecture. Although the IBM PC was designed for expandability, the designers could not anticipate the hardware developments of the 1980s, nor the size of the industry they would engender. To make things worse, IBM's choice of
4818-465: Is commonly called UEFI-GPT booting . Despite the fact that the UEFI specification requires MBR partition tables to be fully supported, some UEFI firmware implementations immediately switch to the BIOS-based CSM booting depending on the type of boot disk's partition table, effectively preventing UEFI booting to be performed from EFI System Partition on MBR-partitioned disks. Such a boot scheme
4964-552: Is commonly called UEFI-MBR . It is also common for a boot manager to have a textual user interface so the user can select the desired OS (or setup utility) from a list of available boot options. To ensure backward compatibility, UEFI firmware implementations on PC-class machines could support booting in legacy BIOS mode from MBR-partitioned disks through the Compatibility Support Module (CSM) that provides legacy BIOS compatibility. In this scenario, booting
5110-411: Is housed in a wide, short steel chassis intended to support the weight of a CRT monitor. The front panel is made of plastic, with an opening where one or two disk drives can be installed. The back panel houses a power inlet and switch, a keyboard connector, a cassette connector and a series of tall vertical slots with blank metal panels which can be removed in order to install expansion cards. Internally,
5256-713: Is performed in the same way as on legacy BIOS-based systems, by ignoring the partition table and relying on the content of a boot sector . BIOS-style booting from MBR-partitioned disks is commonly called BIOS-MBR , regardless of it being performed on UEFI or legacy BIOS-based systems. Furthermore, booting legacy BIOS-based systems from GPT disks is also possible, and such a boot scheme is commonly called BIOS-GPT . The Compatibility Support Module allows legacy operating systems and some legacy option ROMs that do not support UEFI to still be used. It also provides required legacy System Management Mode (SMM) functionality, called CompatibilitySmm , as an addition to features provided by
5402-495: Is recommended to be at least 512 MB in size and formatted with a FAT32 filesystem for maximum compatibility. For backward compatibility , some UEFI implementations also support booting from MBR-partitioned disks through the Compatibility Support Module (CSM) that provides legacy BIOS compatibility. In that case, booting Linux on UEFI systems is the same as on legacy BIOS-based systems. Some of
5548-406: Is required for devices shipping with Windows 8 and above. It is also possible for operating systems to access UEFI configuration data. As of version 2.5, processor bindings exist for Itanium, x86, x86-64, ARM (AArch32) and ARM64 (AArch64). Only little-endian processors can be supported. Unofficial UEFI support is under development for POWERPC64 by implementing TianoCore on top of OPAL,
5694-483: Is taken over by the GPT's Primary Header and Primary Partition Table ). Commonly 1 MB in size, this partition's Globally Unique Identifier (GUID) in GPT scheme is 21686148-6449-6E6F-744E-656564454649 and is used by GRUB only in BIOS-GPT setups. From GRUB's perspective, no such partition type exists in case of MBR partitioning. This partition is not required if the system is UEFI-based because no embedding of
5840-519: The ExitBootServices() call), and they include text and graphical consoles on various devices, and bus, block and file services. Runtime services are still accessible while the operating system is running; they include services such as date, time and NVRAM access. Beyond loading an OS, UEFI can run UEFI applications , which reside as files on the EFI system partition . They can be executed from
5986-531: The Amiga , have been relegated to niche, enthusiast markets. In the past, the most successful exception was Apple 's Macintosh platform, which used non-Intel processors from its inception. Although Macintosh was initially based on the Motorola 68000 series , then transitioned to the PowerPC architecture, Macintosh computers transitioned to Intel processors beginning in 2006. Until 2020 Macintosh computers shared
IBM PC–compatible - Misplaced Pages Continue
6132-626: The IBM PS/2 computer that overcame many of the technical limits of the XT/AT bus, but this was rarely used as the basis for IBM-compatible computers since it required license payments to IBM both for the PS/2 bus and any prior AT-bus designs produced by the company seeking a license. This was unpopular with hardware manufacturers and several competing bus standards were developed by consortiums, with more agreeable license terms. Various attempts to standardize
6278-640: The IBM System/23 Datamaster . The 62-pin expansion bus slots were also designed to be similar to the Datamaster slots, and its keyboard design and layout became the Model F keyboard shipped with the PC, but otherwise the PC design differed in many ways. The 8088 motherboard was designed in 40 days, with a working prototype created in four months, demonstrated in January 1981. The design
6424-533: The Intel 8088 for the CPU introduced several limitations for developing software for the PC compatible platform. For example, the 8088 processor only had a 20-bit memory addressing space . To expand PC s beyond one megabyte, Lotus, Intel, and Microsoft jointly created expanded memory (EMS), a bank-switching scheme to allow more memory provided by add-in hardware, and accessed by a set of four 16- kilobyte "windows" inside
6570-631: The Macintosh computers offered by Apple Inc. and used mainly for desktop publishing at the time, the aging 8-bit Commodore 64 which was selling for $ 150 by this time and became the world's bestselling computer, the 32-bit Commodore Amiga line used for television and video production and the 32-bit Atari ST used by the music industry. However, IBM itself lost the main role in the market for IBM PC compatibles by 1990. A few events in retrospect are important: Despite popularity of its ThinkPad set of laptop PC's, IBM finally relinquished its role as
6716-606: The Multimedia PC (MPC) standard was set during 1990. A PC that met the minimum MPC standard could be marketed with the MPC logo, giving consumers an easy-to-understand specification to look for. Software that could operate on the most minimally MPC-compliant PC would be guaranteed to operate on any MPC. The MPC level 2 and MPC level 3 standards were set later, but the term "MPC compliant" never became popular. After MPC level 3 during 1996, no further MPC standards were established. By
6862-506: The PC-98 ). The IBM PC was sold in high enough volumes to justify writing software specifically for it, and this encouraged other manufacturers to produce machines that could use the same programs, expansion cards , and peripherals as the PC. The x86 computer marketplace rapidly excluded all machines which were not hardware-compatible or software-compatible with the PC. The 640 KB barrier on "conventional" system memory available to MS-DOS
7008-510: The Unified EFI Forum . UEFI is independent of platform and programming language, but C is used for the reference implementation TianoCore EDKII. The original motivation for EFI came during early development of the first Intel–HP Itanium systems in the mid-1990s. BIOS limitations (such as 16-bit real mode , 1 MB addressable memory space, assembly language programming, and PC AT hardware) had become too restrictive for
7154-551: The VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), and the Accelerated Graphics Port (AGP). Descendants of the x86 IBM PC compatibles, namely 64-bit computers based on " x86-64 /AMD64" chips comprise the majority of desktop computers on the market as of 2021, with the dominant operating system being Microsoft Windows . Interoperability with the bus structure and peripherals of
7300-528: The 20-bit addressing. Later, Intel CPUs had larger address spaces and could directly address 16 MB (80286) or more, causing Microsoft to develop extended memory (XMS) which did not require additional hardware. "Expanded" and "extended" memory have incompatible interfaces, so anyone writing software that used more than one megabyte had to provide for both systems for the greatest compatibility until MS-DOS began including EMM386, which simulated EMS memory using XMS memory. A protected mode OS can also be written for
7446-506: The 5100 had a price tag as high as $ 20,000. Their entry into the home computer market needed to be competitively priced. In 1980, IBM president John Opel, recognizing the value of entering this growing market, assigned William C. Lowe and Philip Don Estridge as heads of the new Entry Level Systems unit in Boca Raton, Florida. Market research found that computer dealers were very interested in selling an IBM product, but they insisted
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#17327719759687592-432: The 80286, but DOS application compatibility was more difficult than expected, not only because most DOS applications accessed the hardware directly, bypassing BIOS routines intended to ensure compatibility, but also that most BIOS requests were made by the first 32 interrupt vectors, which were marked as "reserved" for protected mode processor exceptions by Intel. Video cards suffered from their own incompatibilities. There
7738-532: The BIOS setup utility. Computers using the UEFI might need to be set at legacy BIOS mode to be able to boot DOS. However, the BIOS/UEFI options in most mass-produced consumer-grade computers are very limited and cannot be configured to truly handle OSes such as the original variants of DOS. The spread of the x86-64 architecture has further distanced current computers' and operating systems' internal similarity with
7884-407: The BIOS using CSM booting . Contrary to its predecessor BIOS which is a de facto standard originally created by IBM as proprietary software, UEFI is an open standard maintained by an industry consortium . Intel developed the original Extensible Firmware Interface ( EFI ) specification. The last Intel version of EFI was 1.10 released in 2005. Subsequent versions have been developed as UEFI by
8030-509: The CPU's I/O lines. IBM referred to these as "I/O slots", but after the expansion of the PC clone industry they became retroactively known as the ISA bus . At the back of the machine is a metal panel, integrated into the steel chassis of the system unit, with a series of vertical slots lined up with each card slot. Unified Extensible Firmware Interface Unified Extensible Firmware Interface ( UEFI , / ˈ juː ɪ f aɪ / or as an acronym)
8176-908: The Compatibility Support module of affected motherboards. In August 2023, Intel announced that it planned to phase out support CSM for server platforms by 2024. As of today, all computers based on Intel platforms no longer have CSM support. The UEFI specification includes support for booting over network via the Preboot eXecution Environment (PXE). PXE booting network protocols include Internet Protocol ( IPv4 and IPv6 ), User Datagram Protocol (UDP), Dynamic Host Configuration Protocol (DHCP), Trivial File Transfer Protocol (TFTP) and iSCSI . OS images can be remotely stored on storage area networks (SANs), with Internet Small Computer System Interface (iSCSI) and Fibre Channel over Ethernet (FCoE) as supported protocols for accessing
8322-491: The Corporate Management Committee, which converted the group into a business unit named "Project Chess", and provided the necessary funding and authority to do whatever was needed to develop the computer in the given timeframe. The team received permission to expand to 150 people by the end of 1980, and in one day more than 500 IBM employees called in asking to join. The design process was kept under
8468-680: The EFI specification at version 1.10, and contributed it to the Unified EFI Forum , which has developed the specification as the Unified Extensible Firmware Interface (UEFI). The original EFI specification remains owned by Intel, which exclusively provides licenses for EFI-based products, but the UEFI specification is owned by the UEFI Forum. Version 2.0 of the UEFI specification was released on 31 January 2006. It added cryptography and security. Version 2.1 of
8614-408: The EFI's practices and data formats mirror those of Microsoft Windows . The 64-bit versions of Windows Vista SP1 and later and 64-bit versions of Windows 8 , 8.1 , 10 , and 11 can boot from a GPT disk that is larger than 2 TB . EFI defines two types of services: boot services and runtime services . Boot services are available only while the firmware owns the platform (i.e., before
8760-488: The Handwell Corporation were threatened with legal action by IBM, who settled with them. Soon after in 1982, Compaq released the very successful Compaq Portable , also with a clean-room reverse-engineered BIOS, and also not challenged legally by IBM. Early IBM PC compatibles used the same computer buses as their IBM counterparts, switching from the 8-bit IBM PC and XT bus to the 16-bit IBM AT bus with
8906-510: The IBM 5150's lifecycle and only usable with dedicated software support (i.e. only accessible via a RAM window in the Upper Memory Area ); this was relatively rarely equipped and utilized on the original IBM PC, much less fully so, thus the machine's maximum RAM configuration as commonly understood was 640 KB. The BIOS is the firmware of the IBM PC, occupying one 8 KB chip on the motherboard. It provides bootstrap code and
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#17327719759689052-631: The IBM BIOS and then write its own BIOS using clean room design . Note this was over a year after Compaq released the Portable. The money and research put into reverse-engineering the BIOS was a calculated risk. At the same time, many manufacturers such as Tandy / RadioShack , Xerox , Hewlett-Packard , Digital Equipment Corporation , Sanyo , Texas Instruments , Tulip , Wang and Olivetti introduced personal computers that supported MS-DOS, but were not completely software- or hardware-compatible with
9198-454: The IBM PC compatibles remained very much compatible with the original IBM PC computers, although most of the components implement the compatibility in special backward compatibility modes used only during a system boot . It was often more practical to run old software on a modern system using an emulator rather than relying on these features. In 2014 Lenovo acquired IBM's x86-based server ( System x ) business for US$ 2.1 billion . One of
9344-641: The IBM PC compatibles: try the package you want to use before you buy the computer." Companies modified their computers' BIOS to work with newly discovered incompatible applications, and reviewers and users developed stress tests to measure compatibility; by 1984 the ability to operate Lotus 1-2-3 and Flight Simulator became the standard, with compatibles specifically designed to run them. IBM believed that some companies such as Eagle, Corona, and Handwell infringed on its copyright, and after Apple Computer, Inc. v. Franklin Computer Corp. successfully forced
9490-435: The IBM PC offered a port for connecting a cassette data recorder . Unlike the typical home computer however, this was never a major avenue for software distribution, probably because very few PCs were sold without floppy drives. The port was removed on the very next PC model, the XT. At release, IBM did not offer any hard disk drive option and adding one was difficult - the PC's stock power supply had inadequate power to run
9636-399: The IBM PC was very significant to its success in the market. Some publications highlighted IBM's uncharacteristic decision to publish complete, thorough specifications of the system bus and memory map immediately on release, with the intention of fostering a market of compatible third-party hardware and software. The motherboard includes five 62-pin card edge connectors which are connected to
9782-466: The IBM PC. Tandy described the Tandy 2000 , for example, as having a "'next generation' true 16-bit CPU", and with "More speed. More disk storage. More expansion" than the IBM PC or "other MS-DOS computers". While admitting in 1984 that many PC DOS programs did not work on the computer, the company stated that "the most popular, sophisticated software on the market" was available, either immediately or "over
9928-1208: The IBM PC. At first, few clones other than Compaq's offered truly full compatibility. Jerry Pournelle purchased an IBM PC in mid-1983, " rotten keyboard and all", because he had "four cubic feet of unevaluated software, much of which won't run on anything but an IBM PC. Although a lot of machines claim to be 100 percent IBM PC compatible, I've yet to have one arrive ... Alas, a lot of stuff doesn't run with Eagle, Z-100, Compupro , or anything else we have around here". Columbia Data Products's November 1983 sales brochure stated that during tests with retail-purchased computers in October 1983, its own and Compaq's products were compatible with all tested PC software, while Corona and Eagle's were less compatible. Columbia University reported in January 1984 that Kermit ran without modification on Compaq and Columbia Data Products clones, but not on those from Eagle or Seequa. Other MS-DOS computers also required custom code. By December 1983 Future Computing stated that companies like Compaq, Columbia Data Products, and Corona that emphasized IBM PC compatibility had been successful, while non-compatible computers had hurt
10074-428: The IBM PC. Many companies were reluctant to have their products' PC compatibility tested. When PC Magazine requested samples from computer manufacturers that claimed to produce compatibles for an April 1984 review, 14 of 31 declined. Corona specified that "Our systems run all software that conforms to IBM PC programming standards. And the most popular software does." When a BYTE journalist asked to test Peachtext at
10220-645: The Linux kernel's UEFI boot stub . In addition to the standard PC disk partition scheme that uses a master boot record (MBR), UEFI also works with the GUID Partition Table (GPT) partitioning scheme, which is free from many of the limitations of MBR. In particular, the MBR limits on the number and size of disk partitions (up to four primary partitions per disk, and up to 2 TB (2 × 2 bytes ) per disk) are relaxed. More specifically, GPT allows for
10366-592: The OEM versions of MS-DOS were virtually identical, except perhaps for the provision of a few utility programs. MS-DOS provided adequate functionality for character-oriented applications such as those that could have been implemented on a text-only terminal . Had the bulk of commercially important software been of this nature, low-level hardware compatibility might not have mattered. However, in order to provide maximum performance and leverage hardware features (or work around hardware bugs), PC applications quickly developed beyond
10512-409: The OS boot loader, with the path varying depending on the computer architecture . The format of the file path is defined as <EFI_SYSTEM_PARTITION>\EFI\BOOT\BOOT<MACHINE_TYPE_SHORT_NAME>.EFI ; for example, the file path to the OS loader on an x86-64 system is \efi\boot\bootx64.efi , and \efi\boot\bootaa64.efi on ARM64 architecture. Booting UEFI systems from GPT-partitioned disks
10658-432: The OS. This allows the OS to rely on EFI for drivers to perform basic graphics and network functions before, and if, operating-system-specific drivers are loaded. In other cases, the EFI driver can be filesystem drivers that allow for booting from other types of disk volumes. Examples include efifs for 37 file systems (based on GRUB2 code), used by Rufus for chain-loading NTFS ESPs. The EFI 1.0 specification defined
10804-537: The OpenPOWER abstraction layer, running in little-endian mode. Similar projects exist for MIPS and RISC-V . As of UEFI 2.7, RISC-V processor bindings have been officially established for 32-, 64- and 128-bit modes. Standard PC BIOS is limited to a 16-bit processor mode and 1 MB of addressable memory space, resulting from the design based on the IBM 5150 that used a 16-bit Intel 8088 processor. In comparison,
10950-575: The PC community is stifling innovation because so many other companies are mimicking Big Blue", but The Economist stated in November 1983, "The main reason why an IBM standard is not worrying is that it can help competition to flourish". By 1983, IBM had about 25% of sales of personal computers between $ 1,000 and $ 10,000 , and computers with some PC compatibility were another 25%. As the market and competition grew IBM's influence diminished. In November 1985 PC Magazine stated "Now that it has created
11096-462: The PC, covering such features as the bytecoding for color monitors, DMA access operation, and the keyboard interface. They were never enforced. Many of the designers were computer hobbyists who owned their own computers, including many Apple II owners, which influenced the decisions to design the computer with an open architecture and publish technical information so others could create compatible software and expansion slot peripherals. During
11242-459: The PC, is even more vulnerable. Numerous PC-compatible machines—the grapevine says 60 or more—have begun to appear in the marketplace. By June 1983 PC Magazine defined "PC 'clone ' " as "a computer [that can] accommodate the user who takes a disk home from an IBM PC, walks across the room, and plugs it into the 'foreign' machine". Because of a shortage of IBM PCs that year, many customers purchased clones instead. Columbia Data Products produced
11388-546: The Spring 1983 COMDEX , Corona representatives "hemmed and hawed a bit, but they finally led me ... off in the corner where no one would see it should it fail". The magazine reported that "Their hesitancy was unnecessary. The disk booted up without a problem". Zenith Data Systems was bolder, bragging that its Z-150 ran all applications people brought to test with at the 1984 West Coast Computer Faire . Creative Computing in 1985 stated, "we reiterate our standard line regarding
11534-485: The UEFI SMM. An example of such a legacy SMM functionality is providing USB legacy support for keyboard and mouse, by emulating their classic PS/2 counterparts. In November 2017, Intel announced that it planned to phase out support CSM for client platforms by 2020. In July, of 2022, Kaspersky Labs published information regarding a Rootkit designed to chain boot malicious code on machines using Intel's H81 chipset and
11680-405: The UEFI Shell, by the firmware's boot manager , or by other UEFI applications. UEFI applications can be developed and installed independently of the original equipment manufacturers (OEMs). A type of UEFI application is an OS boot loader such as GRUB , rEFInd , Gummiboot , and Windows Boot Manager , which loads some OS files into memory and executes them. Also, an OS boot loader can provide
11826-579: The UEFI specification was released on 7 January 2007. It added network authentication and the user interface architecture ('Human Interface Infrastructure' in UEFI). In October 2018, Arm announced Arm ServerReady , a compliance certification program for landing the generic off-the-shelf operating systems and hypervisors on Arm-based servers. The program requires the system firmware to comply with Server Base Boot Requirements (SBBR). SBBR requires UEFI, ACPI and SMBIOS compliance. In October 2020, Arm announced
11972-628: The UEFI specification. When a computer is powered on, the boot manager checks the boot configuration and, based on its settings, then executes the specified OS boot loader or operating system kernel (usually boot loader ). The boot configuration is defined by variables stored in NVRAM , including variables that indicate the file system paths to OS loaders or OS kernels. OS boot loaders can be automatically detected by UEFI, which enables easy booting from removable devices such as USB flash drives . This automated detection relies on standardized file paths to
12118-514: The [PC] market, the market doesn't necessarily need IBM for the machines. It may depend on IBM to set standards and to develop higher-performance machines, but IBM had better conform to existing standards so as to not hurt users". In January 1987, Bruce Webster wrote in Byte of rumors that IBM would introduce proprietary personal computers with a proprietary operating system : "Who cares? If IBM does it, they will most likely just isolate themselves from
12264-520: The chassis is dominated by a motherboard which houses the CPU, built-in RAM, expansion RAM sockets, and slots for expansion cards. The IBM PC was highly expandable and upgradeable, but the base factory configuration included: The PC is built around a single large circuit board called a motherboard which carries the processor, built-in RAM, expansion slots, keyboard and cassette ports, and the various peripheral integrated circuits that connected and controlled
12410-469: The clone makers to stop using the BIOS. The Phoenix BIOS in 1984, however, and similar products such as AMI BIOS , permitted computer makers to legally build essentially 100%-compatible clones without having to reverse-engineer the PC BIOS themselves. A September 1985 InfoWorld chart listed seven compatibles with 256 KB RAM, two disk drives, and monochrome monitors for $ 1,495 to $ 2,320 , while
12556-467: The company use a design based on standard parts, not IBM-designed ones so that stores could perform their own repairs rather than requiring customers to send machines back to IBM for service. Another source cites time pressure as the reason for the decision to use third-party components. Atari proposed to IBM in 1980 that it act as original equipment manufacturer for an IBM microcomputer, a potential solution to IBM's known inability to move quickly to meet
12702-567: The components of the machine. The peripheral chips included an Intel 8259 PIC , an Intel 8237 DMA controller, and an Intel 8253 PIT . The PIT provides 18.2 Hz clock "ticks" and dynamic memory refresh timing. The CPU is an Intel 8088 , a cost-reduced form of the Intel 8086 which largely retains the 8086's internal 16-bit logic, but exposes only an 8-bit bus. The CPU is clocked at 4.77 MHz, which would eventually become an issue when clones and later PC models offered higher CPU speeds that broke compatibility with software developed for
12848-423: The computer marketplace of the time. Until then Microsoft's business was based primarily on computer languages such as BASIC . The established small system operating software was CP/M from Digital Research which was in use both at the hobbyist level and by the more professional of those using microcomputers. To achieve such widespread use, and thus make the product viable economically, the OS had to operate across
12994-456: The computer's hardware directly and to instead make standard calls to BIOS functions that carried out hardware-dependent operations. This software would run on any machine using MS-DOS or PC DOS. Software that directly addressed the hardware instead of making standard calls was faster, however; this was particularly relevant to games. Software addressing IBM PC hardware in this way would not run on MS-DOS machines with different hardware (for example,
13140-469: The design constraint to use off-the-shelf parts . The TMS9900 was rejected as it was inferior to the Intel 8088. IBM chose the 8088 over the similar but superior 8086 because Intel offered a better price for the former and could provide more units, and the 8088's 8-bit bus reduced the cost of the rest of the computer. The 8088 had the advantage that IBM already had familiarity with the 8085 from designing
13286-534: The design process IBM avoided vertical integration as much as possible, for example choosing to license Microsoft BASIC rather than utilizing the in-house version of BASIC used for mainframes due to the better existing public familiarity with the Microsoft version. The IBM PC debuted on August 12, 1981, after a twelve-month development. Pricing started at $ 1,565 for a configuration with 16 KB RAM, Color Graphics Adapter , keyboard, and no disk drives. The price
13432-547: The dominant market player only to be virtually wiped out by Intel a year later. Intel has been the uncontested leader ever since. As the "Wintel" platform gained dominance Intel gradually abandoned the practice of licensing its technologies to other chipset makers; in 2010 Intel was involved in litigation related to their refusal to license their processor bus and related technologies to other companies like Nvidia . Companies such as AMD and Cyrix developed alternative x86 CPUs that were functionally compatible with Intel's. Towards
13578-584: The end of the 1990s, AMD was taking an increasing share of the CPU market for PCs. AMD even ended up playing a significant role in directing the development of the x86 platform when its Athlon line of processors continued to develop the classic x86 architecture as Intel deviated with its NetBurst architecture for the Pentium 4 CPUs and the IA-64 architecture for the Itanium set of server CPUs. AMD developed AMD64,
13724-469: The equivalent IBM PC cost $ 2,820 . The inexpensive Leading Edge Model D is even compatible with IBM proprietary diagnostic software, unlike the Compaq Portable. By 1986 Compute! stated that "clones are generally reliable and about 99 percent compatible", and a 1987 survey in the magazine of the clone industry did not mention software compatibility, stating that "PC by now has come to stand for
13870-619: The exception rather than the rule. Instead of placing importance on compatibility with the IBM PC, vendors began to emphasize compatibility with Windows . In 1993, a version of Windows NT was released that could operate on processors other than the x86 set. While it required that applications be recompiled, which most developers did not do, its hardware independence was used for Silicon Graphics (SGI) x86 workstations–thanks to NT's Hardware abstraction layer (HAL), they could operate NT (and its vast application library). No mass-market personal computer hardware vendor dared to be incompatible with
14016-536: The extension of the program to the edge and IoT market. The new program name is Arm SystemReady . Arm SystemReady defined the Base Boot Requirements ( BBR ) specification that currently provides three recipes, two of which are related to UEFI: 1) SBBR: which requires UEFI, ACPI and SMBIOS compliance suitable for enterprise level operating environments such as Windows, Red Hat Enterprise Linux, and VMware ESXi; and 2) EBBR: which requires compliance to
14162-465: The first IBM PC went on sale. There were three operating systems (OS) available for it. The least expensive and most popular was PC DOS made by Microsoft . In a crucial concession, IBM's agreement allowed Microsoft to sell its own version, MS-DOS , for non-IBM computers. The only component of the original PC architecture exclusive to IBM was the BIOS (Basic Input/Output System). IBM at first asked developers to avoid writing software that addressed
14308-568: The first computer more or less compatible with the IBM PC standard during June 1982, soon followed by Eagle Computer . Compaq announced its first product, an IBM PC compatible in November 1982, the Compaq Portable . The Compaq was the first sewing machine-sized portable computer that was essentially 100% PC-compatible. The court decision in Apple v. Franklin , was that BIOS code was protected by copyright law, but it could reverse-engineer
14454-423: The first major extension not created by Intel, which Intel later adopted as x86-64 . During 2006 Intel began abandoning NetBurst with the release of their set of "Core" processors that represented a development of the earlier Pentium III. A major alternative to Wintel domination is the rise of alternative operating systems since the early 2000s, which marked as the start of the post-PC era . This would include both
14600-461: The hardware, for a variety of reasons: The first thing to think about when considering an IBM-compatible computer is, "How compatible is it?" In May 1983, Future Computing defined four levels of compatibility: During development, Compaq engineers found that Microsoft Flight Simulator would not run because of what subLOGIC 's Bruce Artwick described as "a bug in one of Intel's chips", forcing them to make their new computer bug compatible with
14746-496: The interfaces were made, but in practice, many of these attempts were either flawed or ignored. Even so, there were many expansion options, and despite the confusion of its users, the PC compatible design advanced much faster than other competing designs of the time, even if only because of its market dominance. During the 1990s, IBM's influence on PC architecture started to decline. "IBM PC compatible" becomes "Standard PC" in 1990s, and later " ACPI PC" in 2000s. An IBM-brand PC became
14892-412: The kernel switches back again). As of version 3.15, the Linux kernel supports 64-bit kernels to be booted on 32-bit UEFI firmware implementations running on x86-64 CPUs, with UEFI handover support from a UEFI boot loader as the requirement. UEFI handover protocol deduplicates the UEFI initialization code between the kernel and UEFI boot loaders, leaving the initialization to be performed only by
15038-450: The keyboard was extremely positive, with some sources describing it as a major selling point of the PC and even as "the best keyboard available on any microcomputer." At release, IBM provided a Game Control Adapter which offered a 15-pin port intended for the connection of up to two joysticks, each having two analog axes and two buttons. (The early PCs predated the advent of the " Windows, Icons, Mouse, Pointer" concept and so did not have
15184-516: The larger server platforms Itanium was targeting. The effort to address these concerns began in 1998 and was initially called Intel Boot Initiative . It was later renamed to Extensible Firmware Interface (EFI). The first open source UEFI implementation, Tiano, was released by Intel in 2004. Tiano has since then been superseded by EDK and EDK II and is now maintained by the TianoCore community. In July 2005, Intel ceased its development of
15330-411: The largest marketplace, in which they really can't compete anymore anyway". He predicted that in 1987 the market "will complete its transition from an IBM standard to an Intel/MS-DOS/expansion bus standard ... Folks aren't so much concerned about IBM compatibility as they are about Lotus 1-2-3 compatibility". By 1992, Macworld stated that because of clones, "IBM lost control of its own market and became
15476-471: The late 1990s, the success of Microsoft Windows had driven rival commercial operating systems into near-extinction, and had ensured that the "IBM PC compatible" computer was the dominant computing platform . This meant that if a developer made their software only for the Wintel platform, they would still be able to reach the vast majority of computer users. The only major competitor to Windows with more than
15622-428: The latest version of Windows, and Microsoft's annual WinHEC conferences provided a setting in which Microsoft could lobby for—and in some cases dictate—the pace and direction of the hardware of the PC industry. Microsoft and Intel had become so important to the ongoing development of PC hardware that industry writers began using the word Wintel to refer to the combined hardware-software system. This terminology itself
15768-487: The latter becoming the most popular. Because of the great number of third-party adapters and no standard for them, programming the PC could be difficult. Professional developers would operate a large test-suite of various known-to-be-popular hardware combinations. Meanwhile, consumers were overwhelmed by the competing, incompatible standards and many different combinations of hardware on offer. To give them some idea of what sort of PC they would need to operate their software,
15914-411: The latter provided medium- and low-resolution color graphics and text. CGA used the same scan rate as NTSC television , allowing it to provide a composite video output which could be used with any compatible television or composite monitor , as well as a direct-drive TTL output suitable for use with any RGBI monitor using an NTSC scan rate. IBM also sold the 5153 color monitor for this purpose, but it
16060-505: The market, rumors of clones began, and the first legal PC-compatible clone—the MPC 1600 by Columbia Data Products —was released in June 1982, less than a year after the PC's debut. Eventually, IBM sold its PC business to Lenovo in 2004 . For low cost and a quick design turnaround time, the hardware design of the IBM PC used entirely "off-the-shelf" parts from third party manufacturers, rather than unique hardware designed by IBM. The PC
16206-458: The market, sold only 69,000. Software support from the industry grew rapidly, with the IBM nearly instantly becoming the primary target for most microcomputer software development. One publication counted 753 software packages available a year after the PC's release, four times as many as were available for the Macintosh a year after its launch. Hardware support also grew rapidly, with 30–40 companies competing to sell memory expansion cards within
16352-567: The most obvious use was the addition of an Intel 8087 math coprocessor, which improved floating-point math performance. PC mainboards were manufactured with the first memory bank of initially Mostek 4116-compatible, or later 4164-compatible DIP DRAMs soldered to the board, for a minimum configuration of first just 16 KB, or later 64 KB of RAM. Memory upgrades were provided by IBM and third parties both for socketed installation in three further onboard banks, and as ISA expansion cards. The early 16 KB mainboards could be upgraded to
16498-521: The new computer did not need to fear that future IBM products would be incompatible with the Compaq, because such changes would also affect millions of real IBM PCs: "In sticking it to the competition, IBM would be doing the same to its own people". After IBM announced the OS/2 -oriented PS/2 line in early 1987, sales of existing DOS-compatible PC compatibles rose, in part because the proprietary operating system
16644-415: The new product. Reception was overwhelmingly positive, with analysts estimating sales volume in the billions of dollars in the first few years after release. After release, IBM's PC immediately became the talk of the entire computing industry. Dealers were overwhelmed with orders, including customers offering pre-payment for machines with no guaranteed delivery date. By the time the machine began shipping,
16790-585: The next six months". Like IBM, Microsoft's apparent intention was that application writers would write to the application programming interfaces in MS-DOS or the firmware BIOS, and that this would form what would now be termed a hardware abstraction layer . Each computer would have its own Original Equipment Manufacturer (OEM) version of MS-DOS, customized to its hardware. Any software written for MS-DOS would operate on any MS-DOS computer, despite variations in hardware design. This expectation seemed reasonable in
16936-531: The old BIOS-based firmware interface, or have their CSMs disabled, cannot natively run MS-DOS since MS-DOS depends on a BIOS interface to boot. Only the Macintosh had kept significant market share without having compatibility with the IBM PC, although that changed during the Intel Macs era running Mac OS X , often dual-booting Windows with Boot Camp . IBM decided in 1980 to market a low-cost single-user computer as quickly as possible. On August 12, 1981,
17082-508: The original IBM PC by introducing yet another processor mode with an instruction set modified for 64-bit addressing, but x86-64 capable processors also retain standard x86 compatibility. IBM Personal Computer The IBM Personal Computer (model 5150, commonly known as the IBM PC ) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard . Released on August 12, 1981, it
17228-430: The original IBM PC, including the Intel -based Mac computers manufactured from 2006 to 2022 . Prior to the 1980s, IBM had largely been known as a provider of business computer systems. As the 1980s opened, their market share in the growing minicomputer market failed to keep up with competitors, while other manufacturers were beginning to see impressive profits in the microcomputer space. The market for personal computers
17374-419: The original PC architecture may be limited or non-existent. Many modern computers are unable to use old software or hardware that depends on portions of the IBM PC compatible architecture which are missing or do not have equivalents in modern computers. For example, computers which boot using Unified Extensible Firmware Interface -based firmware that lack a Compatibility Support Module, or CSM, required to emulate
17520-503: The original PC. The single base clock frequency for the system was 14.31818 MHz, which when divided by 3, yielded the 4.77 MHz for the CPU (which was considered close enough to the then 5 MHz limit of the 8088), and when divided by 4, yielded the required 3.579545 MHz for the NTSC color carrier frequency. The PC motherboard included a second, empty socket, described by IBM simply as an "auxiliary processor socket", although
17666-520: The original XT circuits: one 8237 DMA controller, one 8253 interrupt timer, one 8255 parallel interface controller, one 8259 interrupt controller, one 8284 clock generator, and one 8288 bus controller. Similar non-Intel chipsets appeared for the AT-compatibles, for example OPTi's 82C206 or 82C495XLC which were found in many 486 and early Pentium systems. The x86 chipset market was very volatile though. In 1993, VLSI Technology had become
17812-440: The personal computer market ; the specifications of the IBM PC became one of the most popular computer design standards in the world. The only significant competition it faced from a non-compatible platform throughout the 1980s was from Apple 's Macintosh product line, as well as consumer-grade platforms created by companies like Commodore and Atari . Most present-day personal computers share architectural features in common with
17958-414: The processor mode in a UEFI environment can be either 32-bit ( IA-32 , AArch32) or 64-bit ( x86-64 , Itanium, and AArch64). 64-bit UEFI firmware implementations support long mode , which allows applications in the preboot environment to use 64-bit addressing to get direct access to all of the machine's memory. UEFI requires the firmware and operating system loader (or kernel) to be size-matched; that is,
18104-449: The production of large, sophisticated and expensive business systems. As with other large computer companies, its new products typically required about four to five years for development, and a well publicized quote from an industry analyst was, "IBM bringing out a personal computer would be like teaching an elephant to tap dance." IBM had previously produced microcomputers, such as 1975's IBM 5100 , but targeted them towards businesses;
18250-503: The rapid growth of the smartphones (using Android or iOS) as an alternative to the personal computer; and the increasing prevalence of Linux and Unix-like operating systems in the server farms of large corporations such as Google or Amazon. The term "IBM PC compatible" is not commonly used presently because many current mainstream desktop and laptop computers are based on the PC architecture, and IBM no longer makes PCs. The competing hardware architectures have either been discontinued or, like
18396-685: The release of the AT. IBM's introduction of the proprietary Micro Channel architecture (MCA) in its PS/2 series resulted in the establishment of the Extended Industry Standard Architecture bus open standard by a consortium of IBM PC compatible vendors, redefining the 16-bit IBM AT bus as the Industry Standard Architecture (ISA) bus. Additional bus standards were subsequently adopted to improve compatibility between IBM PC compatibles, including
18542-541: The reputations of others like TI and DEC despite superior technology. At a San Francisco meeting it warned 200 attendees, from many American and foreign computer companies as well as IBM itself, to "Jump on the IBM PC-compatible bandwagon—quickly, and as compatibly as possible". Future Computing said in February 1984 that some computers were "press-release compatible", exaggerating their actual compatibility with
18688-539: The same effect, but this did not easily extend to the greater color depths and higher resolutions offered by SVGA adapters. An attempt at creating a standard named VESA BIOS Extensions (VBE) was made, but not all manufacturers used it. When the 386 was introduced, again a protected mode OS could be written for it. This time, DOS compatibility was much easier because of virtual 8086 mode . Unfortunately programs could not switch directly between them, so eventually, some new memory-model APIs were developed, VCPI and DPMI ,
18834-493: The same software that a contemporary IBM or Lenovo PC could. The term was initially in contrast to the variety of home computer systems available in the early 1980s, such as the Apple II , TRS-80 , and Commodore 64 . Later, the term was primarily used in contrast to Commodore 's Amiga and Apple 's Macintosh computers. These "clones" duplicated almost all the significant features of the original IBM PC architectures. This
18980-481: The same system architecture as their Wintel counterparts and could boot Microsoft Windows without a DOS Compatibility Card . However, with the transition to the internally developed ARM -based Apple silicon , they are again the exception to IBM compatibility. The processor speed and memory capacity of modern PCs are many orders of magnitude greater than they were for the original IBM PC and yet backwards compatibility has been largely maintained –
19126-424: The second-stage code is needed in that case. UEFI systems can access GPT disks and boot directly from them, which allows Linux to use UEFI boot methods. Booting Linux from GPT disks on UEFI systems involves creation of an EFI system partition (ESP), which contains UEFI applications such as bootloaders, operating system kernels, and utility software. Such a setup is usually referred to as UEFI-GPT , while ESP
19272-431: The simple terminal applications that MS-DOS supported directly. Spreadsheets , WYSIWYG word processors , presentation software and remote communication software established new markets that exploited the PC's strengths, but required capabilities beyond what MS-DOS provided. Thus, from very early in the development of the MS-DOS software environment, many significant commercial software products were written directly to
19418-569: The strengths of the PC-compatible design is its modular hardware design. End-users could readily upgrade peripherals and, to some degree, processor and memory without modifying the computer's motherboard or replacing the whole computer, as was the case with many of the microcomputers of the time. However, as processor speed and memory width increased, the limits of the original XT/AT bus design were soon reached, particularly when driving graphics video cards. IBM did introduce an upgraded bus in
19564-496: The term "IBM PC compatible" is now a historical description only, as the vast majority of microcomputers produced since the 1990s are IBM compatible. IBM itself no longer sells personal computers, having sold its division to Lenovo in 2005. " Wintel " is a similar description that is more commonly used for modern computers. The designation "PC", as used in much of personal computer history , has not meant "personal computer" generally, but rather an x86 computer capable of running
19710-407: The term "PC" was becoming a household name. Sales exceeded IBM's expectations by as much as 800% (9x), with the company at one point shipping as many as 40,000 PCs per month. IBM estimated that home users made up 50 to 70% of purchases from retail stores. In 1983, IBM sold more than 750,000 machines, while Digital Equipment Corporation , one of the companies whose success had spurred IBM to enter
19856-480: Was created by a team of engineers and designers at International Business Machines (IBM), directed by William C. Lowe and Philip Don Estridge in Boca Raton, Florida . Powered by an x86 -architecture Intel 8088 processor, the machine was based on open architecture and third-party peripherals. Over time, expansion cards and software technology increased to support it. The PC had a substantial influence on
20002-402: Was designed to compete with comparable machines in the market. For comparison, the Datamaster, announced two weeks earlier as IBM's least expensive computer, cost $ 10,000. IBM's marketing campaign licensed the likeness of Charlie Chaplin 's character " The Little Tramp " for a series of advertisements based on Chaplin's movies, played by Billy Scudder. The PC was IBM's first attempt to sell
20148-538: Was dominated at the time by Tandy , Commodore , and Apple , whose machines sold for several hundred dollars each and had become very popular. The microcomputer market was large enough for IBM's attention, with $ 15 billion in sales by 1979 and projected annual growth of more than 40% during the early 1980s. Other large technology companies had entered it, such as Hewlett-Packard , Texas Instruments and Data General , and some large IBM customers were buying Apples. As early as 1980 there were rumors of IBM developing
20294-406: Was essentially complete by April 1981, when it was handed off to the manufacturing team. PCs were assembled in an IBM plant in Boca Raton, with components made at various IBM and third party factories. The monitor was an existing design from IBM Japan ; the printer was manufactured by Epson . Because none of the functional components were designed by IBM, they obtained only a handful of patents on
20440-431: Was facilitated by IBM's choice of commodity hardware components , which were cheap, and by various manufacturers' ability to reverse-engineer the BIOS firmware using a " clean room design " technique. Columbia Data Products built the first clone of the IBM personal computer , the MPC 1600 by a clean-room reverse-engineered implementation of its BIOS. Other rival companies, Corona Data Systems , Eagle Computer , and
20586-438: Was for several years sold only as an OEM product. There was no Microsoft-branded MS-DOS: MS-DOS could not be purchased directly from Microsoft, and each OEM release was packaged with the trade dress of the given PC vendor. Malfunctions were to be reported to the OEM, not to Microsoft. However, as machines that were compatible with IBM hardware—thus supporting direct calls to the hardware—became widespread, it soon became clear that
20732-540: Was initially developed for the IBM Datamaster , and was substantially better than the keyboards provided with virtually all home computers on the market at that time in many regards - number of keys, reliability and ergonomics. While some home computers of the time utilized chiclet keyboards or inexpensive mechanical designs, the IBM keyboard provided good ergonomics, reliable and positive tactile key mechanisms and flip-up feet to adjust its angle. Public reception of
20878-477: Was no standard interface for using higher-resolution SVGA graphics modes supported by later video cards. Each manufacturer developed their own methods of accessing the screen memory, including different mode numberings and different bank switching arrangements. The latter were used to address large images within a single 64 KB segment of memory. Previously, the VGA standard had used planar video memory arrangements to
21024-405: Was not available at release and was not released until March 1983. MDA scanned at a higher frequency and required a proprietary monitor, the IBM 5151 . The card also included a built-in printer port. Both cards could also be installed simultaneously for mixed graphics and text applications. For instance, AutoCAD , Lotus 1-2-3 and other software allowed use of a CGA Monitor for graphics and
21170-460: Was not available. In 1988, Gartner Group estimated that the public purchased 1.5 clones for every IBM PC. By 1989 Compaq was so influential that industry executives spoke of "Compaq compatible", with observers stating that customers saw the company as IBM's equal or superior. After 1987, IBM PC compatibles dominated both the home and business markets of commodity computers, with other notable alternative architectures being used in niche markets, like
21316-461: Was published in August 2022. The interface defined by the EFI specification includes data tables that contain platform information, and boot and runtime services that are available to the OS loader and OS. UEFI firmware provides several technical advantages over a BIOS: With UEFI, it is possible to store product keys for operating systems such as Windows, on the UEFI firmware of the device. UEFI
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