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This article refers to the original IBM PC, for the article about IBM-like PCs in general, see IBM PC compatible The IBM Personal Computer, commonly known as the IBM PC, was the original version and progenitor of the IBM PC compatible hardware platform. It was IBM model number 5150, and was introduced on August 12, 1981. It was created by a team of engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida. The term "personal computer" was common currency before 1981, and was used as early as 1972 to characterize Xerox PARC's Alto. However, because of the success of the IBM PC, what had been a generic term came to mean specifically a microcomputer compatible with IBM's specification. During the second quarter of 2005, the Chinese Lenovo Group secured the rights to produce IBM-branded personal computers. This move reflects IBM's present focus on server/mainframe markets and business consulting and information technology services. Note the following distinctions within the general subject of personal computers:
The IBM PC concept The original PC was an IBM attempt to get into the home computer market then dominated by the Apple II and a host of CP/M machines. By the end of the 1970s, indeed, apart from the existing IBM 5110 Datamaster marketed by its General Systems Division (GSD) there was already yet another entrant, from IBM Instruments Inc.* Rather than going through the usual IBM design process, which had already failed to design an affordable microcomputer (the unsuccessful IBM 5100), a special team was assembled with authorization to bypass normal company restrictions and get something to market rapidly. This project was given the code name Project Chess. Thus the first effective product champion, in 1980, was William C Lowe, the manager of the Entry Systems Unit, in Boca Raton, Florida, where the PC eventually came to be manufactured. It was he who conceived the project and assembled the thirteen engineers who later entered legend as the 'Dirty Dozen'; and finally obtained the go-ahead from the CMC towards the end of 1980. The ease with which this permission was partly to do with John Opel's drive at that time for 'intrapreneurial' Independent Business Units, but mainly because it was seen as peripheral to IBM's business as usual. The PC was only expected to have a lifetime demand of 250,000 units, and only needed $14 million in start up capital. The truth is that nobody else in IBM wanted it. Even though there was a real buzz about the new project, Richard Young (then President of IBM's Office Products Division, OPD, which might have seemed the most obvious home for it) said he had no intention of forcing it on his sales force. Worse, although he supported the idea of it being sold through OPD's 'Product Centers', he opposed it being sold elsewhere (since that might mean the dealers, such as Computerland and Sear Business Centers would also want to sell IBM's typewriters!). Fortunately he was overruled by Opel. * According to Buck Rodgers, then an IBM Vice President, they were given the brief "We want an IBM Personal Computer. We're already late, so you'll have to hurry. Do whatever you feel is necessary to get it done". In a matter of only a few months he and his small team then put together the whole PC operation. Indeed, the first demonstration model (put together to show the July 1980 CMC) was assembled from the standard components - which were to become the PC's special feature - in just 30 days! * The team consisted of just twelve people headed by Don Estridge. They succeeded in developing the PC in about a year. To achieve this they first decided to build the machine with "off-the-shelf" parts from a variety of different original equipment manufacturers (OEMs) and countries. Previously IBM had developed their own components. Second, they decided on an open architecture so that other manufacturers could produce and sell peripheral components and compatible software. The ROM BIOS source code was published. IBM did not anticipate that its competitors would find ways to legally duplicate the entire system. At the time, Don Estridge and his team considered using the 801 processor and its operating system that had been developed at the IBM research laboratory in Yorktown Heights, New York (The 801 was an early RISC microprocessor designed by John Cocke and his team at Yorktown Heights.) The 801 was at least an order of magnitude more powerful than the Intel 8088, and the operating system many years more advanced than the DOS operating system from Microsoft, that were finally selected. Ruling out an in-house solution made the team’s job much easier and may have avoided a delay in the schedule, but the ultimate consequences of this decision for IBM were far-reaching. IN the event, IBM signed with Intel for its 8088 chip, a decision which would have been difficult to avoid, Tandon for the disk drives (unusually for IBM as a single-source supplier which was to pose problems later), SCI Systems for the circuit boards and Zenith for the power supplies. Epson was to supply the separate printers. Some bits, just a select few (such as the keyboard, though even this was non-standard), were from other parts of IBM. The printer (a standard Epson, rebadged) was almost immediately to prove somewhat of an embarrassment when Epson started to sell their next generation, improved, printer for less! But it was a period when there was considerable emphasis in the IBU's on sub contracting as much as possible. Other manufacturers soon reverse engineered the BIOS to produce their own non-infringing functional copies. Columbia Data Products introduced the first IBM-PC compatible computer in June 1982. Compaq Computer Corporation announced the Compaq Portable, the first portable IBM PC compatible in November 1982 (it did not ship until March 1983). Once the IBM PC became a commercial success the PC came back under the usual IBM management control, with the result that competitors had little trouble taking the lead from them. (In this regard, IBM's tradition of "rationalizing" their product lines—deliberately restricting the performance of lower-priced models in order to prevent them from "cannibalizing" profits from higher-priced models—worked against them). As of June 2006, IBM PC and XT models are still in use at the majority of U.S. National Weather Service upper-air observing sites. The computers are used to process data as it is returned from the ascending radiosonde, attached to a weather balloon. They are being phased out over a several year period, to be replaced by the Radiosonde Replacement System. Third-party distribution channels Sears Roebuck and Computerland executives were involved with the IBM team from the start. The IBMers - especially H.L. ('sparky') Sparks, who was in charge of sales and marketing - relied on them for much of their knowledge of the marketplace. In turn, almost by default, they were to become the main outlets for the new product. Sears Roebuck would set up a handful of centers and, most important, the more than 190 stores of Computerland already existed. From IBM's point of view, this meant that even at announcement there would be immediate widespread distribution across the US. In the event, Sears Roebuck failed to live up to expectations, when the new PC turned out to be selling to the office market rather than the home - where it had originally been targeted. The use of outside organisations ('third parties' in IBM terminology) to sell IBM's products did not stop with the PC; for the whole of IBM's business had gradually evolved to the state where it was selling ever larger numbers of ever cheaper 'boxes'. The only way that IBM felt - at that time - it could, in general, handle the numbers of these new customers was by handing over the lower end of its business to 'retailers'; an approach that many other companies had successfully adopted in the past - from the producers of groceries (whose experience may not all have been totally relevant, though their experience of advertising to large numbers of end users might have been) to the manufacturers of cars (most of whose experiences, from handling their dealers to advertising on the large scale, might have been very relevant indeed). Certainly, by the end of the 1990s, more PCs were being sold worldwide than cars or even TVs. IBM PC models The models of IBM's first-generation Personal Computer (PC) series have names: The second generation IBM Personal System/2 (PS/2), are known by model number: Model 25, Model 30. Within each series, the models are also commonly referenced by their CPU clock rate. All IBM personal computers are software compatible with each other in general, but not every program will work in every machine. Some programs are time sensitive to a particular speed class. Older programs will not take advantage of newer higher-resolution display standards. Electronics The main circuit board in an IBM PC is called the motherboard. This carries the CPU and memory, and has a bus with slots for expansion cards. The bus used in the original PC became very popular, and was subsequently named ISA. It is in use to this day in computers for industrial use. Later, requirements for higher speed and more capacity forced the development of new versions. IBM introduced the MCA bus with the PS/2 line. The VESA Local Bus allowed for up to three, much faster 32-bit cards, and the EISA architecture was developed as a backward compatible standard including 32-bit card slots, but it only sold well in high-end server systems. The lower-cost and more general PCI bus was introduced in 1994 and has now become ubiquitous. The motherboard is connected by cables to internal storage devices such as hard disks, floppy disks and CD-ROM drives. These tend to be made in standard sizes, such as 3.5" (90 mm) and 5.25" (133.4 mm) widths, with standard fixing holes. The case also contains a standard power supply unit (PSU) which is either an AT or ATX standard size. Intel 8086 and 8088-based PCs require EMS (expanded memory) boards to work with more than one megabyte of memory. The original IBM PC AT used an Intel 80286 processor which can access up to 16 megabytes of memory (though standard DOS applications cannot use more than one megabyte without using additional APIs.) Intel 80286-based computers running under OS/2 can work with the maximum memory. Keyboard The original 1981 IBM PC's keyboard at the time was an extremely reliable and high quality keyboard originally developed in North Carolina for another $10,000 IBM computer system that had been canceled. Each key was rated to be reliable to over 100 million keystrokes. Compared to the keyboards of other small computers at the time, the IBM PC keyboard was the Rolls-Royce of its time and played a significant role in establishing a high quality impression. Byte magazine in the fall of 1981 went so far as to state that the keyboard was 50% of the reason to buy an IBM PC. The importance of the keyboard was definitely established when the IBM PC Junior flopped, in very large part for having a much different and mediocre keyboard that made a poor impression on customers. Oddly enough, the same thing almost happened to the IBM PC when in early 1981 management seriously considered substituting a cheaper but lower quality keyboard. But this mistake was narrowly avoided by the advice of one of the original development engineers. However, the original 1981 IBM PC's keyboard was severely criticised by typists for its non-standard placement of the return and left shift keys. In 1984, IBM corrected this on its AT keyboard, but shortened the backspace key, making it harder to reach. In 1987, it introduced the enhanced keyboard, which relocated all the function keys and the Ctrl keys. The Esc key was also relocated to the opposite side of the keyboard. An "IBM PC compatible" may have a keyboard which does not recognize every key combination a true IBM PC does, e.g. shifted cursor keys. In addition, the "compatible" vendors sometimes used proprietary keyboard interfaces, preventing the keyboard from being replaced. See also: Keyboard layout Character set The original IBM PC used the 7-bit ASCII alphabet as its basis, but extended it to 8 bits with nonstandard character codes. This character set was not suitable for some international applications, and soon a veritable cottage industry emerged providing variants of the original character set in various national variants. In IBM tradition, these variants were called code pages. These codings are now obsolete, having been replaced by more systematic and standardized forms of character coding, such as ISO 8859-1, Windows-1251 and Unicode. This was the original IBM PC character set: Storage media Officially, the standard storage medium for the original IBM PC model 5150 was a cassette drive. Technologically obsolete even by 1981 standards, it was seldom used, and few (if any) IBM PCs left the factory without a floppy disk drive installed. The 1981 PC had one or two 160 kilobyte 5¼ inch single-sided double-density floppy disk drives; XTs generally had one double-sided 360 kB drive (next to the hard disk). The first IBM PC that included a fixed, non-removable, hard disk was the XT. Hard disks for IBM compatibles soon became available with very large storage capacities. If a hard disk was added that was not compatible with the existing disk controller, a new controller board had to be plugged in; some disks were integrated with their controller in a single expansion board, commonly called a "Hard Card." In 1984, IBM introduced the 1.2 megabyte dual sided floppy disk along with its AT model. Although often used as backup storage, the high density floppy was not often used for interchangeability. In 1986, IBM introduced the 720 kB double density 3.5" microfloppy disk on its Convertible laptop computer. It introduced the 1.44 MB high density version with the PS/2 line. These disk drives could be added to existing older model PCs. In 1988 IBM introduced a drive for 2.88 MB "DSED" diskettes in its top-of-the-line models; it was an instant failure and is all but forgotten today (but survives as a possible "size" choice in disk-formatting utilities). Original Software All IBM PCs includes a relatively small piece of software stored in ROM. The original IBM PC 40 kB ROM included 8 kB for power-on self-test (POST) and basic input/output system (BIOS) functions plus 32 kB BASIC in ROM (Cassette BASIC). The ROM BASIC interpreter was the default user interface if no DOS boot disk was present. BASICA was distributed on floppy disk and provided a way to run the ROM BASIC under PC-DOS control. IBM PC and PS/2 models
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