A home computer was a class of personal computer entering the market in 1977 and becoming common during the 1980s. They were marketed to consumers as accessible personal computers, more capable than video game consoles. These computers typically cost much less than business, scientific or engineering-oriented desktop personal 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 personal computers. Usually they were purchased for education, game play, and personal productivity use such as word processing. Advertisements for early home computers were rife with possibilities for their use in the home, from cataloguing recipes to personal finance to home automation, but these were seldom realized in practice as they usually required the home computer user to learn computer programming; a significant time commitment many weren't willing to make. Still, for many the home computer offered the first possibility to learn to program.
The home computer became affordable for the general public due to the mass production of the microprocessor. Early microcomputers had front-mounted switches and blinkenlights to control and indicate internal system status and often came in kit form. In contrast, home computers were designed to be used by the average consumer, not necessarily an electronics hobbyist.
Home computers were sold pre-assembled in molded plastic cases, which were more attractive to consumers and lower cost than the card-cage enclosures used by the Altair and similar computers. A keyboard was usually built into the case. Ports for plug-in peripheral devices such as a video display, cassette tape recorders, joysticks, and (later) disk drives either were provided or available as add-on cards. Usually the manufacturer would provide all the peripheral devices practical to add to any system as extra cost accessories. Often peripherals were not interchangeable between brands of home computer (or sometimes even between successive models of the same brand). To save the cost of a dedicated monitor, the home computer often would have connected either directly or through an RF modulator to the family TV set as video display and sound system.
Almost universally, home computers had a version of the BASIC programming language in read-only permanent memory. One exception was the Jupiter Ace, which had the Forth language built in. A programming language was seen as a requirement for any computer of the era due to the dearth of commercially-available productivity software.
Computers are used in the home more than ever today, but the line between a 'business' computer and a 'home' computer has blurred, since they will use the same operating system, processor architecture, and peripherals.
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.
Low-end home computers competed with video game consoles. The markets weren't entirely distinct, as both could be used for games. 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, educational software, word processing, spreadsheet and other applications while the game console showed a blank screen or continued playing the same repetitive game. Books were available for most models of computer with titles along the lines of "64 Amazing BASIC Games for the Commodore 64" and were a popular means of both learning to program and software distribution. Some video game consoles offered "programming packs", consisting of a version of BASIC in a ROM cartridge. For the ColecoVision console Coleco even announced an expansion module which should convert it into a full-fledged computer system, but this never materialised, and instead the Coleco Adam was announced. 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. The concept of a computer platform did not exist, except for the Japanese MSX standard.
The introduction of the IBM Personal Computer in August 1981 would eventually lead to standardization in personal computers, largely due to the system's open architecture, which encouraged production of third-party clones of the unit. While the Apple II would be quickly displaced by the IBM PC for office use, Apple Computer's 1984 release of the Apple Macintosh created a new model for the home computer which IBM-compatible computers would eventually imitate.
The declining cost of IBM-compatible "personal computers" on the one hand, and the greatly increased graphics, sound, and storage capabilities of dedicated video game consoles on the other, caused 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 purchased 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.
Many home computers were superficially similar. Most had a keyboard integrated into the case; sometimes a cheap-to-manufacture 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. The use of a television set as a display almost defines the pre-PC home computer. Although dedicated computer monitors were available for this market segment, it was often a later purchase only made 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 home computers. Many first time computer buyers brought a base C-64 system home to find they needed to purchase a disk drive or Datassette before they could make use of it as anything but a game machine.
In the early part of the 1980s, home computers were mostly based on 8-bit microprocessor technology, typically the MOS Technology 6502 or the Zilog Z80. A notable exception was the TI-99 series, announced in 1979 with a 16-bit TMS9900 CPU.
Processor clock rates were typically 1–2 MHz for 6502 based CPU's and 2–4 MHz for Z80 based systems, but this aspect of performance was not emphasized by users or manufacturers, as dealing with the systems' limited RAM capacity, graphics capabilities and storage options took priority. Clock speed was considered a technical detail of interest only to users needing accurate timing. 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.
Many home computers initially used the then-ubiquitous compact audio cassettes as a storage mechanism. Most cassette implementations were notoriously slow and unreliable, but floppy disk drives as found on more costly business-oriented microcomputers were expensive and used disks eight inches wide at the beginning of the home computer era. Costs declined toward the end of the 1980s as sales of microcomputers increased and mass production of 5.25" drive mechanisms enabled economy of scale. The 5.25" floppy disk drives would become standard, with 3.5" drives being made available for most systems toward the latter part of the decade. Most software for home computers remained sold on 5.25" disks, however; 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. Various copy protection schemes were developed for floppy disks but most were broken in short order, and many users would only tolerate them for games as wear and tear on disks was a significant issue in an entirely floppy-based system, and having a 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 contrast to modern computers, home computers most often had their OS stored in ROM chips. This made startup times very fast - no more than a few seconds - but made 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. The user interface was usually only a BASIC interpreter coupled to a character-based screen or line editor, with applications performing all other OS duties themselves. As multitasking was not common on home computers until late in the '80s, this lack of API support wasn't much of a liability. Application programs usually accessed hardware directly to perform a specific task, often "switching out" the ROM based OS anyway to free the address space it occupied and maximize RAM capacity. 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 needn't be 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, and application software on cartridge did exist, but the vast majority of cartridges were games.
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 helped to enable the greatly increased abilities of the Amiga and Atari ST series. 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 1040 ST). 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.
All this was predicted to be commonplace sometime before the end of the decade, but virtually every aspect of the predicted revolution would prove not to be or be delayed. 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 purchased 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.
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 may one day replace it. Our coffee may be brewed automatically, but the computer is 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! 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". Likewise, the acceptance of computers into daily life today is a product of continuing refinement of both technology and perception.
Retrocomputing is gaining in popularity, 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.
The list below shows 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.
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, like 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.
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.
(For a comprehensive overview of home computers, i.e. not just the most notable ones given below, see the List of home computers.)
The following computers were also typical of the home computer segment: