Children playing Paperboy on an Amstrad CPC 464 in the 1980s

Most home computers, such as this Tandy Color Computer 3, featured a version of the BASIC programming language. The sometimes-sprawling nature of the well-outfitted home computer system is very much in evidence.

A TI 99/4 with expansion modules attached. No more than a few expansion options were practical with this type of arrangement.

Home computers were a class of microcomputers entering the market in 1977, and becoming common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user. These computers typically cost much less than business, scientific or engineering-oriented computers of the time, and were generally less powerful in terms of memory and expandability. However, a home computer often had better graphics and sound than contemporary business computers and, by far, their most common use was playing video games.

Advertisements for early home computers were rife with possibilities for their practical use in the home, from cataloging recipes to personal finance to home automation,^[1][2][3] but these were seldom realized in practice. For example, using a typical 1980s home computer as a home automation appliance would require the computer to be kept powered on at all times and dedicated to this task. Personal finance and database use required tedious data entry. If no packaged software was available for a particular application, the home computer user was required to learn computer programming; a significant time commitment many new computer owners weren't willing to make. Still, for others the home computer offered the first opportunity to learn to program.^[4]

Today the line between 'business' and 'home' computer market segments has blurred or vanished completely, since both categories of computers now typically use the same processor architectures, peripherals, operating systems, and applications. Often the only difference may be the sales outlet through which they are purchased. Another change from the home computer era is that the once-common endeavour of writing one's own software programs has almost vanished from home computer use.^[5]

Background[link]

As early as 1965, some experimental projects such as Jim Sutherland's ECHO IV explored the possible utility of a computer in the home.^[6][7] In 1969, the Honeywell Kitchen Computer was marketed as a luxury gift item, and would have inaugurated the era of home computing, but none were sold.^[8]

Computers became affordable for the general public in the 1970s due to the mass production of the microprocessor. Early microcomputers such as the Altair 8800 had front-mounted switches and blinkenlights to control and indicate internal system status, and were often sold in kit form to hobbyists. These kits would contain an empty printed circuit board which the buyer would fill with the integrated circuits, other individual electronic components, wires and connectors, and then hand-solder all the connections.^[9]

While two early home computers (Sinclair ZX80, and Acorn Atom) could be bought either in kit form or assembled, most home computers were only sold pre-assembled. They were enclosed in plastic or metal cases similar in appearance to typewriter or hi-fi equipment enclosures, which were more familiar and attractive to consumers than the industrial metal card-cage enclosures used by the Altair and similar computers. A keyboard was usually built into the same case as the motherboard - a feature lacking on the Altair. Ports for plug-in peripheral devices such as a video display, cassette tape recorders, joysticks, and (later) disk drives either were built-in or available on expansion cards. Usually the manufacturer would sell peripheral devices designed to be compatible with their computers as extra cost accessories. Peripherals were not often interchangeable between different brands of home computer, or even between successive models of the same brand.

To save the cost of a dedicated monitor, the home computer often would connect through an RF modulator to the family TV set, which served as both video display and sound system.^[10]

After the success of systems like the RadioShack TRS-80, the Commodore PET and the Apple II in 1977, large numbers of new machines of all types began to appear during the late 1970s and early 1980s. Some home computers sold many units over several years, such as the BBC Micro, Sinclair ZX Spectrum, Atari 800XL and Commodore 64, and attracted third-party software development. By 1982, an estimated 621,000 home computers were in use in the United States, at an average sales price of $530.^[11]

Almost universally, home computers had a BASIC interpreter combined with a line editor in permanent read-only memory which one could use to type in BASIC programs and execute them immediately or save them to tape or disk. In direct mode, the BASIC interpreter was also used as the user interface, and given tasks such as loading, saving, managing, and running files.^[12] One exception was the Jupiter Ace, which had a Forth interpreter instead of BASIC. A built-in programming language was seen as a requirement for any computer of the era, and was the main feature setting home computers apart from video game consoles. The most popular console, the Atari 2600, was based on the same CPU architecture as Atari's computer line.

Still, home computers competed in the same market as the consoles. A home computer was often seen as simply as a higher end purchase than a console, adding abilities to what would still be mainly a gaming device. A common marketing tactic was to show a computer system and console playing games side by side, then emphasising the computer's greater ability by showing it running user-created programs, education software, word processing, spreadsheet and other applications while the game console showed a blank screen or continued playing the same repetitive game.

Some consoles offered "programming packs" consisting of a version of BASIC in a ROM cartridge. Atari's BASIC Programming for the Atari 2600 was one of these. For the ColecoVision console, Coleco even announced an expansion module which would convert it into a full-fledged computer system. This never materialised, but a standalone computer, the Coleco Adam was eventually released.^[13]

Books of type-in program listings were available for most models of computer with titles along the lines of "64 Amazing BASIC Games for the Commodore 64".^[14] While most of the programs in these books were short and simple arcade-type games, some titles such as Compute!'s SpeedScript series, contained productivity software that rivalled commercial packages. To avoid the tedious process of typing in a program listing from a book, these books would sometimes include a mail-in offer from the author to obtain the programs on disk or cassette for a few dollars. Before the Internet, and before most computer owners had a modem, books were a popular and low-cost means of software distribution. They also served a role in familiarizing new computer owners with the concepts of programming; some titles added suggested modifications to the program listings for the user to carry out. Modifying software to fit one's needs or be compatible with one's system was a skill every advanced computer owner was expected to have.

During the peak years of the home computer market, scores of models were produced, usually with little or no thought given to compatibility between different manufacturers or even within product lines of one manufacturer.^[15] The concept of a computer platform did not exist, except for the Japanese MSX standard.^[16]

Things were different in the business world, where cost-conscious small business owners had been using CP/M running on Z-80 based computers from Osborne, Kaypro, Morrow Designs and a host of other manufacturers. Soon after its August 1981 introduction, the IBM Personal Computer would eventually become the standard platform used in business, largely due to the system's open architecture, which encouraged production of third-party clones of the design. The 6502-based Apple II series had carved out a niche for itself in business, largely thanks to the industry's first killer app, VisiCalc. However the Apple II would quickly be displaced for office use by IBM PCs and Lotus 1-2-3.^[17] Apple Computer's 1984 release of the Apple Macintosh introduced the modern GUI to the market, which IBM-compatible computers would eventually adopt.^[18] Throughout the 1980s, PCs spread through businesses like wildfire, leading, by the end of the decade, to sub-$1000 IBM PC XT-class white box machines, usually built in Asia and sold by US companies like PCs Limited.

The declining cost of IBM-compatibles on the one hand, and the greatly increased graphics, sound, and storage abilities of fourth generation video game consoles such as the Sega Genesis and Super Nintendo Entertainment System on the other, combined to cause the market segment for home computers to vanish by the early 1990s in the US. In Europe, the home computer remained a distinct presence for a few years more, with the Amiga and Atari ST lines being the dominant players, but today a computer bought for home use anywhere will be very similar to those used in offices - made by the same manufacturers, with compatible peripherals, operating systems, and application software.

Technology[link]

A Commodore 64c system, showing the basic layout of a typical home computer system of the era. Pictured are the CPU/keyboard unit, floppy disk drive, and dedicated color monitor. Many systems also had a dot matrix printer for producing paper output.

Eastern Bloc computers were often significantly different in appearance from western computers. Pictured is a KC 85/3 with its keyboard placed on top, by VEB Mikroelektronik Mühlhausen released in 1986 and based on an East German Zilog Z80 clone.

The Soviet Elektronika BK0010-01 home computer was based on the К1801ВМ1 (Soviet LSI-11-compatible CPU) and shared architectural similarities with PDP-11.

Many home computers were superficially similar. Most had a keyboard integrated into the case; sometimes a cheap-to-make membrane or chiclet keyboard in the early days, although full-travel keyboards quickly became universal due to overwhelming consumer preference. Most systems could use an RF modulator to display 20–40 column text output on a home television. Indeed, the use of a television set as a display almost defines the pre-PC home computer. Although dedicated composite or "green screen" computer displays were available for this market segment and offered sharper text display and sometimes increased graphics resolution, a monitor was often a later purchase made only after users had bought a floppy disk drive, printer, modem, and the other pieces of a full system. This "peripherals sold separately" approach is another defining characteristic of the home computer era. Many first time computer buyers brought a base C-64 system home and hooked it up to their TV only to find they needed to buy a compatible disk drive (the Commodore 1541 was the only fully compatible model) or Datassette before they could make use of it as anything but a game machine.

In the early part of the 1980s, the dominant microprocessors used in home computers were the 8-bit MOS Technology 6502 (Apple, Commodore, Atari) and Zilog Z80 (TRS-80). A notable exception was the TI-99 series, announced in 1979 with a 16-bit TMS9900 CPU.^[19]

Processor clock rates were typically 1–2 MHz for 6502 based CPU's and 2–4 MHz for Z80 based systems (yielding roughly equal performance), but this aspect was not emphasized by users or manufacturers, as the systems' limited RAM capacity, graphics abilities and storage options had more of an effect on performance than CPU speed. Clock rate was considered a technical detail of interest only to users needing accurate timing for their own programs. To economize on component cost, often the same crystal used to produce color television compatible signals was also divided down and used for the processor clock. This meant processors rarely operated at their full rated speed, and had the side-effect that European and North American versions of the same home computer operated at slightly different speeds and different video resolution due to different television standards.

Initially, many home computers used the then-ubiquitous compact audio cassette as a storage mechanism. A rough analogy to how this worked would be to place a recorder on the phone line as a file was uploaded by modem to "save" it, and playing the recording back through the modem to "load". Most cassette implementations were notoriously slow and unreliable, but early 8 inch floppy disk drives as found on more costly business-oriented microcomputers were large and prohibitively expensive. Smaller and cheaper^[20] 5.25" form factor drives gained popularity before mass production decreased prices still further, and 5.25" floppy disk drives would remain standard until the end of the 8-bit era. Though external 3.5" drives were made available for home computer systems toward the latter part of the 1980s, most software sold for 8-bit home computers remained on 5.25" disks; 3.5" drives were used for data storage. Standardization of disk formats was not common; sometimes even different models from the same manufacturer used different disk formats. Toward the end of the home computer era, drives for a number of home computer models appeared offering disk-format compatibility with the IBM PC. The disk drives sold with the Commodore 128, Amiga and Atari ST were all able to read and write PC disks, which themselves were undergoing the transition from 5.25" to 3.5" format at the time.

Various copy protection schemes were developed for floppy disks; most were broken in short order. Many users would only tolerate copy protection for games, as wear and tear on disks was a significant issue in an entirely floppy-based system. The ability to make a "working backup" disk of vital application software was seen as important. Copy programs that advertised their ability to copy or even remove common protection schemes were a common category of utility software in this pre-DMCA era.

In contrast to modern computers, home computers most often had their operating system (OS) stored in ROM chips. This made startup times very fast - no more than a few seconds - but made OS upgrades difficult or impossible without buying a new unit. Usually only the most severe bugs were fixed by issuing new ROMs to replace the old ones at the user's cost. In another defining characteristic of the home computer, instead of a command line, the BASIC interpreter served double duty as a user interface. Coupled to a character-based screen or line editor, BASIC's file management commands could be entered in direct mode. The operating systems provided little other support to application programs, but application programs usually accessed hardware directly to perform a specific task anyway, often switching out the ROM based OS completely to free the address space it occupied and maximize RAM capacity. As multitasking was not common on home computers until late in the '80s, this lack of API support wasn't much of a liability.

In an enduring reflection of their early cassette-oriented nature, most home computers loaded their disk operating system (DOS) separately from the main OS. The DOS was only used to send commands to the floppy disk drive and was not loaded to perform other computing functions. One notable exception was Commodore, whose disk drives actually contained a 6502 processor and Commodore DOS in ROM. Many home computers also had a cartridge interface which accepted ROM-based software. This was occasionally used for expansion or upgrades such as fast loaders. Application software on cartridge did exist, and eliminated the need for disk swapping on single drive systems, but the vast majority of cartridges were games.^[21]

From about 1985, the high end of the home computer market began to be dominated by "next generation" home computers using the 16-bit Motorola 68000 chip, which enabled the greatly increased abilities of the Amiga and Atari ST series. Graphics resolutions approximately doubled, and color palettes increased from dozens to hundreds or thousands of colors available. Stereo sound became standard for the first time. Clock rates on these systems were approximately 8 MHz with RAM capacities of 256 kB (for the base Amiga 1000 system) up to 1024 kB (1 megabyte, a milestone, first seen on the Atari 1040ST). These systems used 3.5" floppy disks from the beginning but 5.25" drives were made available to facilitate data exchange with IBM PC compatibles. The Amiga and ST both had GUIs inspired by the Apple Macintosh, but at a list price of $2495 (over $5000 in 2007 dollars), the Macintosh itself was too expensive for most households.

Radio frequency interference[link]

After the first wave of computers landed in American homes, the United States Federal Communications Commission (FCC) began receiving complaints of electromagnetic interference to television reception. By 1979 the FCC demanded that home computer makers submit samples for radio frequency interference testing. It was found that "first generation" home computers, which often included their own screens, emitted too much radio frequency noise for household use. Some companies appealed to the FCC to waive the requirements for home computers, while others (with compliant designs) objected to the waiver. Eventually techniques to suppress interference became standardized.^[22]

The Home Computer "Revolution"[link]

This section is written like a personal reflection or essay rather than an encyclopedic description of the subject. Please help improve it by rewriting it in an encyclopedic style. (September 2010)

In the late 1970s and early 1980s, from about 1977 to 1983, it was widely predicted ^[23] that computers would soon revolutionize many aspects of home and family life as they had business practices in the previous decades.^[24] Mothers would keep their recipe catalog in "kitchen computer" databases and turn to a medical database for help with child care, fathers would use the family's computer to manage family finances and track automobile maintenance. Children would use disk-based encyclopedias for school work and would be avid video gamers. Home automation would bring about the intelligent home of the '80s. Using Videotex, NAPLPS or some sort of as-yet unrealized computer technology, television would gain interactivity. The "personalized newspaper" (to be displayed on the computer screen) was a commonly-predicted application. Morning coffee would be brewed automatically under computer control. The same computer would control the house lighting and temperature. Robots would take the garbage out, and be programmed to perform new tasks via the home computer. Electronics were expensive, so it was generally assumed that each home would have only one multitasking computer for the entire family to use in a timesharing arrangement, with interfaces to the various devices it was expected to control.

All this was predicted to be commonplace sometime before the end of the decade, but virtually every aspect of the predicted revolution would be delayed or prove entirely impractical. The computers available to consumers of the time period just weren't powerful enough to perform any single task required to realize this vision, much less do them all simultaneously. The home computers of the early 1980s could not multitask. Even if they could, memory capacities were too small to hold entire databases or financial records, floppy disk-based storage was inadequate in both capacity and speed for multimedia work, and the graphics of the systems could only display blocky, unrealistic images and blurry, jagged text. Before long, a backlash set in—computer users were "geeks", "nerds" or worse, "hackers". The North American video game crash of 1983 soured many on home computer technology. The computers that were bought for use in the family room were either forgotten in closets or relegated to basements and children's bedrooms to be used exclusively for games and the occasional book report. In 1977, referring to computers used in home automation at the dawn of the home computer era, Digital Equipment Corporation CEO Ken Olsen is quoted as saying "There is no reason for any individual to have a computer in his home"^[26]

It took another 10 years for technology to mature, for the graphical user interface to make the computer approachable for non-technical users, and for the internet to provide a compelling reason for most people to want a computer in their homes. Predicted aspects of the revolution were left by the wayside or modified in the face of an emerging reality. The cost of electronics dropped precipitously and today many families have a computer for each family member, or a laptop for mom's active lifestyle, a desktop for dad with the kids sharing a computer. Encyclopedias, recipe catalogs and medical databases are kept online and accessed over the world wide web -- not stored locally on floppy disks or CD-ROM. TV has yet to gain substantial interactivity; instead, the web has evolved alongside television, but the HTPC or services like Netflix, Google TV or Apple TV along with internet video sites such as YouTube and Hulu may one day replace traditional broadcast and cable television. Our coffee may be brewed automatically every morning, but the computer is a simple one embedded in the coffee maker, not under external control. As of 2008, robots are just beginning to make an impact in the home, with Roomba and Aibo leading the charge.

This delay wasn't out of keeping with other technologies newly introduced to an unprepared public. Early motorists were widely derided with the cry of "Get a horse!"^[27] until the automobile was accepted. Television languished in research labs for decades before regular public broadcasts began. In an example of changing applications for technology, before the invention of radio, the telephone was used to distribute opera and news reports, whose subscribers were denounced as "illiterate, blind, bedridden and incurably lazy people".^[28] Likewise, the acceptance of computers into daily life today is a product of continuing refinement of both technology and perception.

Use today[link]

As older computer hardware ages and the supply of replacement parts dwindles, it has become popular among enthusiasts^[29] to emulate these machines, their environments^[30] on modern hardware. One of the more well-known emulators is the Multiple Emulator Super System which can emulate most of the better known home computers. A more or less complete list of home computer emulators can be found in the List of computer system emulators article. Games for many 8 and 16 bit home computers are becoming available for the Wii Virtual Console.

Retrocomputing is gaining in popularity^{[neutrality is disputed]}, with many enthusiasts using real Commodore 64 hardware to perform modern tasks such as surfing the web and email. The 64 has also been repackaged as the C-One and C64 Direct-to-TV, both designed by Jeri Ellsworth with modern enhancements.^[31] Many enthusiasts have started to collect home computers, with older and rarer systems being much sought after. Sometimes the collections turn into a virtual museum presented on web sites.^[32]

Notable home computers[link]

The 1977 Apple II with 2 Disk II disk drives and an Apple monitor

The time line below describes many of the most popular or significant home computers of the late 1970s and of the 1980s.

The most popular home computers in the USA up to 1985 were: the TRS-80 (1977), various models of the Apple II family (first introduced in 1977), the Atari 400/800 (1979) along with its follow up models the 800XL and 130XE, and the Commodore VIC-20 (1980) and the Commodore 64 (1982). The VIC was the first computer of any type to sell over one million units, and the 64 is still the highest-selling single model of personal computer ever, with over 17 million produced before production stopped in 1994 – a 12-year run with only minor changes.^[33]

In Europe the situation was slightly different, as many of the British made systems like Sinclair's ZX81 and Spectrum, and later the Amstrad/Schneider CPC were generally much cheaper in Europe than US systems (such as the Atari and Apple models). The reverse was also true, as popular British systems like the Spectrum never became popular in the US. A few British Sinclair models were sold for low prices in the US by Timex Corporation, such as the Timex Sinclair 1000 and the ill-fated Timex Sinclair 2068. The result was that these British systems were much more popular in Europe than in the USA, the only notable exception being the Commodore 64 (C64), which competed favorably price-wise with the British systems, and was the most popular system in Europe as in the USA.^[34][35]

Until the introduction of the IBM PC in 1981, computers such as the Apple II and TRS 80 also found considerable use in office work.^[36][37] The Commodore PET had a sizable presence in the North American education market until that was largely ceded to the Apple II as Commodore focused on the C-64's success in the mass retail market.^[38]

1970s[link]

This unreferenced section requires citations to ensure verifiability.

Three microcomputers were the prototypes for what would later become the home computer market segment; but when introduced they sold as much to hobbyists and small businesses as to the home.

• January 1977: Commodore PET (N. Am.), first all-in-one computer: keyboard/screen/tape storage.
• June 1977: Apple II (North America), color graphics, eight expansion slots; one of the first computers to use a typewriter-like plastic case design.
• August 1977: Tandy Radio Shack TRS-80 (N. Am.), first home computer for less than US$600, used a dedicated monitor for U.S. Federal Communications Commission (FCC) rules compliance.

The following computers also introduced significant advancements to the home computer segment:

• 1979: Atari 400/800 (N. Am.), first computer with custom chip set and programmable video chip and built-in audio output.
• 1979: TI-99/4, first home computer with a 16-bit processor.

1980s[link]

This unreferenced section requires citations to ensure verifiability.

No computer has sold more units than the Commodore 64.^[39]

The East German Robotron KC 85/1 was virtually not available for sale due to huge demand by industrial, educational, and military institutions.

• 1980: Commodore VIC-20 (N. Am.), under US$300; first computer of any kind to pass one million sold.
• 1980: TRS-80 Color Computer (N. Am.), Motorola 6809, optional OS-9 multi-user multi-tasking.
• June 1981: Texas Instruments TI-99/4A, based on the less successful TI-99/4, first to add sprite graphics.
• 1981: Sinclair ZX81 (Europe), £49.95 in kit form; £69.95 pre-built, released as Timex Sinclair 1000 in US in 1982.
• 1981: BBC Micro (Europe) (premier educational computer in the UK for a decade; advanced BBC BASIC with integrated 6502 machine code assembler, featured a myriad of I/O ports, ~ 1.5 million sold.
• April 1982: Sinclair ZX Spectrum (Europe), best-selling British home computer; catalysed the UK software industry, widely cloned by the Soviet Union.
• June 1982: MicroBee (Australia), initially as a kit, then as a finished unit.
• August 1982: Dragon 32(UK) became, for a short time, the best-selling home micro in the United Kingdom.
• August 1982: Commodore 64 (N. Am.), custom graphic & synthesizer chipset, best-selling computer model of all time: ~ 17 million sold.
• Jan. 1983: Apple IIe, Apple II enhanced. Reduced component count and production costs enabled high-volume production, until 1993.
• Apr. 1984: Apple IIc, Apple II compact. No expansion slots, and built-in ports for pseudo-plug and play ease of use. The Apple II most geared to home use, to complement the Apple IIe's dominant education market share.
• 1983: Acorn Electron A stripped down 'sibling' of the BBC microcomputer with limited functionality. The Electron recovered from a slow start to become one of the more popular home computers of that era in the UK.
• 1983: Coleco Adam, one of the few home computers to be sold only as a complete system with storage device and printer; cousin to the ColecoVision game console; one of the first systems to be "orphaned" by its maker, a casualty of the North American video game crash of 1983.
• 1983: MSX (Japan, Korea, the Arab League, Europe, N+S. Am.), a computer 'reference design' by ASCII and Microsoft, produced by several companies: ~ 5 million sold.
• 1983: VTech Laser 200, entry level computer aimed at being the cheapest on market, also sold as Salora Fellow, Texet TX8000 & Dick Smith VZ 200.
• 1983: Oric 1 and Oric Atmos, a home computer equipped with a full travel keyboard and an extended version of Microsoft BASIC in ROM.
• 1984: The Apple Macintosh is introduced, providing many consumers their first look at a graphical user interface, which would eventually replace the home computer as it was known.
• 1984: Amstrad/Schneider, CPC, PCW ranges (Europe), British standard before IBM PC; German sales next to C64.
• 1985: Elektronika BK-0010, one of the first 16-bit home computers, and the only "official" home computer in USSR.
• 1985: Robotron KC 85/1 (Europe), one of the few home computers produced by the East German VEB Robotron-Meßelektronik "Otto Schön" Dresden.
• 1985: Atari ST (N. Am.), first with built-in MIDI interface; also 1MB RAM for less than US$1000; Motorola 68000 processor.
• 1985: Commodore 128 (N. Am.) Final, most advanced 8-bit Commodore, retained full C64 compatibility while adding CP/M in a complex multi-mode architecture
• July 1985: Commodore Amiga (N. Am.), custom chip set for graphics and digital audio; multitasking OS with both GUI and CLI interfaces; Motorola 68000 processor.
• 1986: Apple IIGS, Fifth and final model in the Apple II series, with greatly enhanced graphics and sound abilities. Used a 16-bit 65C816 CPU, the same as used in the Super Nintendo Entertainment System.
• 1987: Acorn Archimedes (Europe), launched with an 8 MHz 32-bit ARM 2 microprocessor, with between 512kB and 4MB of RAM, and an optional 20 or 40MB hard drive.
• 1989: SAM Coupé (Europe), based on 6 MHz Z80 microprocessor; marketed as a logical upgrade from the Sinclair ZX Spectrum.

See also[link]

Wikimedia Commons has media related to: Home computers

• Computer magazines
• History of computing hardware (1960s-present)
• Honeywell 316 a "home computer" from 1969
• List of home computers
• List of home computers by category
• List of home computers by video hardware
• List of video game consoles
• Influence of the IBM PC on the personal computer market
• Microprocessor development board and List of early microcomputers, first microprocessor based systems used by hobbyists
• Personal computer
• Pirates of Silicon Valley - docu-fiction focused on Apple and Microsoft evolution
• Triumph of the Nerds
• Video Display Controller, chips that were used to create the video graphics of many early home computers

References[link]

External links[link]

• Rune's PC Museum
• Home of the home computer
• Collection of old analog and digital computers at Old Computer Museum
• Computer History Museum – An online museum of home computing and gaming
• HCM - Home Computer Museum
• "Total share: 30 years of personal computer market share figures" – From Ars Technica
• article on computing in the 1980s
• Google Books link to A history of the personal computer: the people and the technology By Roy A. Allan