Five waves of home computer: Low-price single-user computers aimed at the home market arrived in five waves between 1976 and 1986:
Trinity of 1977, plus one (1976 to December 1977)
The invention of the
Intel 8080 microprocessor chip in April 1974 made practical the development of the (relatively) affordable mass-market microcomputer. In the USA this first appeared in early 1975 in the form of an unassembled kit, the
Altair 8800; shortly afterward pre-assembled Altairs were offered. The sudden popularity of desktop computers happened because the 8080 CPU could represent and manipulate 256 discrete values in its 8-bit registers. Thus the 7-bit
ASCII standard for the representation of
alphanumeric data became feasible for the first time in a machine much smaller and less expensive than the furniture-size
minicomputers, with their processors that occupied entire circuit boards. This new class of computer was practical for serious work because it could input, process, and output alphanumeric information. It also enabled sophisticated programs such as database managers and
BASIC interpreters to become available to a larger market consisting of people possessing lesser technical skills.
Soon after, other companies entered the market with similar, ready-to-run microcomputers like the
IMSAI 8080. These sold in the tens of thousands, surprising everyone in the industry. Beyond businesses and hobbyists, however, these computers were not widely used because (in the early days) they lacked conveniences like video displays and keyboards, required programming skills at the
machine code level, and systems large enough for serious work cost many thousands.
The very first home computer was the Compucolor by Compucolor Corporation in 1976, soon followed by the
Compucolor II which was made by Intelligent Systems Corp. They used the 8080 but otherwise sported very advanced features, including RAM starting at 8 KB, expandable up to 32 KB, 64 column by 32 line color CRT display, a professional keyboard, an enhanced BASIC interpreter , and a built-in floppy disk drive. It only sold a few thousand units, however, and the company went bust not long after.
In 1975 two new microprocessors were developed that were easier and less expensive to implement than the 8080: the
MOS Technology 6502 and
Zilog Z80. In 1977 three companies decided to use this new technology to develop and market affordable, fully assembled, easy-to-use, programmable computers for individual users in their businesses and homes. These were the
Apple II, and
TRS-80, which Byte magazine christened the "1977 Trinity". These comprise the First Wave of home computers.
All three were instant successes and created a huge, surprise demand. It would not be until 1979, however, when these pioneering manufacturers produced successor machines (1980 in the case of Tandy/Radio Shack). Aside from the efforts of product development and ramping up production to meet the unexpected demand, each had unique difficulties expanding their new businesses. In the cases of Commodore and Apple, they had to build up networks of dealers, not only for sales but for reliable customer service. Tandy/Radio Shack had a great head start in this area because of its some 3500 retail stores in the USA, but still had to work up its repair and training capability for after-sales support. They focused their efforts on the in-house development of hardware peripherals (especially the first 5.25 inch floppy disk drives) and software. Apple and Commodore encouraged third-party companies to do this work for them (except for floppy drives). Tandy also took up the task of establishing a presence in the growing market for small business computers, with its follow-on
TRS-80 Model II which they introduced in October 1979. The TRS-80 took a large, early lead in the new market, and Apple lagged Commodore. Tandy/Radio Shack would hold its number one position until 1982.
Rise of rival 8-bit lines (October 1979 to April 1982)
The Second Wave arrived in October 1979 when the first competitor in the new home computer market,
Texas Instruments, fielded their
TI-99/4 (featuring a CPU that handled 16-bit data, but had an instruction set entirely its own). Established game console maker
Atari followed closely in November with their
400 and 800, which were the first home computers ever to have circuitry dedicated to processing of graphical video and audio data (inherited from Atari game console products). In 1980
Sinclair in the UK launched their super-cheap
ZX80, heralded as the least expensive computer ever offered. Also in early 1980 the Radio Shack
Color Computer made its debut. This was the first commercial computer to use the powerful
Motorola 6809 CPU. In early 1981 Commodore introduced its
VIC-20 which rivaled the Ataris for gameplay with a custom video chip that made hi-res color affordable but not so capable as the Atari's graphics coprocessors. The VIC-20 would become the first computer to sell one million units. Sinclair followed up the ZX80 with its
ZX81 in March 1981. Sinclair would team up with
Timex to market its home computers in the USA. In June Texas Instruments followed up its 99/4 with the improved 99/4A. In December
Acorn Computer in the UK produced the
BBC Micro. Finally in April 1982 Sinclair again topped itself with its new
Spectrum. This last can be seen as a transition between the second wave and the third; successor models of the Spectrum would evolve in that direction.
Essentially, this second wave of home computers were video game consoles equipped with a few computerlike enhancements like keyboards, BASIC interpreters (which served as the operating system), and provision for cassette tape mass storage. They introduced features that would typify the low-end home computer: slots for plug-in cartridges, borrowed from the video game consoles, joystick ports, and the use of the family television set as a video display (the Apple II was the only Trinity computer to allow use of a TV), though provisions were often made for low-cost composite video output.
These lower cost new machines lacked features of more costly machines. One such was the full-travel keyboard. Membrane or "chiclet" keyboards were used in the least expensive models like the Sinclairs, Color Computer, and Atari 400 (as did the Trinity's Commodore PET). A lack of lowercase alpha characters was still typical in the cheaper models, like the Sinclair ZX80/81s. Serial ports and interfaces for printers were offered only on the pricier models. Less expensive memory chips afforded the later computers of this wave of home computer a full complement of RAM: usually 48 KB which with 16 KB of system/BASIC ROM filled out the memory map of the 8-bit CPU. Also in the later period the VIC-20 and Ataris got their first floppy disk drives (The
Commodore 1540 and
Atari 810 respectively). The dedicated video chips used in the Ataris and the software sprites supported by the VIC-20 would spur software publishers to produce a new breed of games with fast-moving high resolution color graphics. The emphasis in the home market on graphics would also compel the writers of the BASIC interpreters to support the new graphics capabilities with advanced commands for drawing lines and geometric shapes and filling areas, rather than the primitive commands for merely setting and resetting pixels as provided in earlier computers.
Golden Age of the 8-bit lines (August 1982 to early 1984)
The first of the mature 8-bit machines that constituted the Third Wave of home computers was the famous
Commodore 64 (August 1982). It sported many features that would typify this generation. Most important was the use of
bank-switching technology to address more than the 64 kilobytes of memory that 8-bit processors were limited to. The C-64 was the first home computer with 64 KB of RAM, using bank-switching to page in ROM routines as needed, thus filling out the 6502's memory map completely with RAM. This made larger, more sophisticated programs possible.
The C-64 eventually drove Texas Instruments from the home computer market with aggressive cost-cutting, and wounded the Atari 8-bit line's market position as well. The C-64 cost less than the Atari 800 and at last had a custom graphics and sound chips of comparable capability. A few years after coming to market the C-64 would sell some 2 million units per year (despite early on acquiring a reputation for poor construction quality and reliability) and went on to become the all-time bestselling computer (in units sold) until the PCs overtook it in the early 1990s. In late 1983 Atari countered Commodore in the low-end "price wars" with its 800XL, which was cheaper to produce and slightly improved, though still limited to 48 KB RAM. Ending this third wave of home computer, 1984 saw new entrant
Amstrad in the UK introduce the
Amstrad CPC. This new Z80 machine would spawn many variants in following years and sell some 3 million units.
As costs for
DRAM chips continued to decline, other 8-bit computers would use bank-switching to offer even more RAM than the 64 KB limit of the 8-bit CPUs. 128 KB was the amount most convenient, as two banks of 64 KB DRAM chips occupied little area on the circuit board and provided a low-cost option by leaving the upper bank empty for later expansion. Three home computers that fit this description were the
ZX Spectrum 128,
Apple IIe (January 1983) and Radio Shack
TRS-80 Model 4 (April 1983). Later the Commodore 128 and Atari 130XE would follow suit with 128 KB of bank-swtiched RAM. The two higher-end home computers by Apple and Tandy/Radio Shack (around $2000 with dual disk drives) brought many features of pricier business computers within reach of the home computerist, such as 80 column text displays, RS-232 serial ports, RAM disks, task switching software, and sophisticated operating systems and applications rivaling the emerging
MS-DOS standard of the professional world. The first of the small computer
Deskmate, would appear on these two computers.
Robotic manufacturing in low-wage Asian countries and advanced, denser circuit design permitted engineers to build in more and better features while reducing production costs, so greater capabilities became available to the consumer at lesser prices. Greater quantities of units shipped drove down costs further as economies of scale kicked in. As sales of home computers sold grew, software publishers increasingly turned their attention to the gaming, educational, and home productivity market. They began to support the more advanced features of the newer computers, especially the greater memory capacities available. Prices of hardware and software continued to fall and spurred further growth and programming sophistication.
Another effect of the mass marketing of home computers was a shift in the distribution channels used by the manufacturers. Particularly for Commodore, Atari, and Sinclair/Timex in the USA, it became feasible to sell through department stores like
J.C. Penney, and toy/hobby stores like
Toys "R" Us. This trend resulted in further price reductions to the consumer, and allowed manufacturers to economically move greater volumes of product into new markets away from the big coastal cities of the USA.
MSX was a standard for a home computing architecture that was intended and hoped to become a universal platform for home computing. It was conceived and engineered by
Microsoft and marketed by Microsoft Japan. Computers conforming to the MSX standard were produced by most all major Japanese electronics manufacturers, as well as two Korean ones and several others in Europe and South America. Some 5 million units are known to have been sold in Japan alone. They sold in smaller numbers throughout the world. Due to the "price wars" being waged in the USA home computer market during the 1983-85 period, MSX computers were never marketed to any great extent in the USA. Eventually more advanced mainstream home computers and game consoles obsoleted the MSX machines.
By the end of this period in early 1984 (with the launch of Amstrad's CPC), all the major lines of 8-bit home computer had been introduced. All subsequent computers designed for home use would use more powerful 16-bit processors, which could more efficiently use the ever-less-expensive memory chips. It was actually the years following 1984 that would be the Golden Age of the 8-bit home computers. They would continue to sell (on price), spawn improved and repackaged versions, and gain an ever-wider selection of software applications and hardware peripherals (many using the same new technologies the 16-bit computers would, such as 3.5 inch floppy disk drives). Indeed, all these 8-bit home computers would persist into the early 1990s (the TRS-80 Model 4D ceased production sometime in the late 1980s but was kept in the Radio Shack catalog until 1991).
January 1984 may be seen as the very beginning of a transition to the new generation of 16-bit computers that would blossom in 1985-86, for this was when Sinclair produced their
Sinclair QL, which was the first home computer to use Motorola's new
68000-series CPU with an internal 32-bit architecture and multitasking operating system. The Sinclair implementation used the 68008 version with an external 8-bit bus. The QL was rushed to market and not much of a success as a product, however.
PCs Invade the Home (March 1984 to November 1984)
From the introduction of the
Personal Computer (ubiquitously known as the PC) in 1981, the market for computers meant for the corporate, business, and government sectors came to be dominated by the new machine and its
MS-DOS operating system. Even basic PCs cost thousands of dollars and were far out of reach for typical home computerists. However, in the following years technological advances and improved manufacturing capabilities (mainly greater use of robotics and relocation of production plants to lower-wage locations in Asia) permitted several computer companies to offer lower-cost PC style machines that would become competitive with many 8-bit home-market pioneers. PCs could never become as affordable as these because the same price-reducing measures were available to all computer makers. Furthermore, software and peripherals for PC style computers tended to cost more than those for 8-bit computers because of the
anchoring effect caused by the pricey IBM PC. Though the PC's first graphics adapter,
CGA, could be used with a television set in 40 character mode, this was not a practical option because very little software was written for this display mode; therefore the PCs could not practically use the family TV set as a video display like the cheaper home computers and thus the effective price of a PC was that much greater. Nonetheless, the overall reduction in manufacturing costs narrowed the price difference between old 8-bit technology and new PCs. In other words, the simpler machines could not benefit so much from more efficient manufacturing as did the complex PCs. Despite their higher absolute prices PCs were perceived by many to be better values for their utility as superior productivity tools and their access to industry-standard software. Another advantage was the 8088/8086's wider 20-bit address bus: the PC could access more than 64 kilobytes of memory relatively inexpensively (8-bit CPUs required complicated, tricky memory management techniques like
bank-switching). Similarly, the PC floppy was double-sided with about twice the storage capacity of floppy disks used by 8-bit home computers. PC drives tended to cost less because they were most often built-in, requiring no external case, controller, and power supply. The faster clock rates and wider buses available to later Intel CPUs compensated somewhat for the custom graphics and sound chips of the Commodores and Ataris. In time the growing popularity of home PCs spurred many software publishers to offer gaming and children's software titles.
Many decision makers in the computer industry believed there could be a viable market for office workers who used PC/DOS computers at their jobs and would appreciate an ability to bring diskettes of data home on weeknights and weekends to continue work after-hours on their "home" computers. So the ability to run industry-standard
MS-DOS software on affordable, user-friendly PCs was anticipated as a source of new sales. Furthermore, many in the industry felt that MS-DOS would eventually (inevitably, it seemed) come to dominate the computer business entirely, and some manufacturers felt the need to offer individual customers PC-style products suitable for the home market.
Another factor that did not hurt home sales of PCs for business computerists was that their cost could be counted as an income tax deduction provided the owner could document to the Internal Revenue Service that the computer was used (for at least fifty percent of the time) for business purposes, or if required for educational purposes. This applied to peripherals and software as well. Since these customers usually occupied the higher tax brackets, the relatively high cost of home and business PCs could be offset substantially.
In early 1984 market colossus IBM produced the
PCjr as a PC/DOS-compatible machine aimed squarely at the home user. It proved a spectacular failure because IBM deliberately limited its capabilities and expansion possibilities in order to avoid cannibalizing sales of the profitable PC. IBM management believed that if they made the PCjr too powerful too many buyers would prefer it over the bigger, more expensive PC. Poor reviews in the computer press and poor sales doomed the PCjr.
Tandy Corporation capitalized on IBM's blunder with its PCjr-compatible
Tandy 1000 in November. Like the PCjr it was pitched as a home, education, and small-business computer featuring joystick ports, better sound and graphics (same as the PCjr but with enhancements), combined with near-PC/DOS compatibility (unlike Tandy's earlier
Tandy 2000). The improved Tandy 1000 video hardware became a standard of its own, known as
Tandy Graphics Adapter or TGA. Later, Tandy produced Tandy 1000 variants in form factors and price-points even more suited to the home computer market, consisting particularly of the Tandy 1000 EX
 and HX
 models (later supplanted by the 1000 RL
), which came in cases resembling the original Apple IIs (CPU, keyboard, expansion slots, and power supply in a slimline cabinet) but also included floppy disk drives. The proprietary
Deskmate productivity suite came bundled with the Tandy 1000s. Deskmate was suited to use by computer novices with its point-and-click (though not graphical) user interface. From the launch of the Tandy 1000 series, their manufacture were price-competitive because of Tandy's use of high-density
ASIC chip technology, which allowed their engineers to integrate many hardware features into the motherboard (obviating the need for circuit cards in expansion slots as with other brands of PC). Tandy never transferred its manufacturing operation to Asia; all Tandy desktop computers were built in the USA (this was not true of the laptop and pocket computers, nor peripherals).
In 1985 the
Epson corporation, a popular and respected producer of inexpensive dot-matrix printers and business computers (the
QX-16), introduced its low-cost
 PC. Its designers took minor shortcuts such as few expansion slots and a lack of a socket for an
8087 math chip, but Epson did bundle some utility programs that offered decent turnkey functionality for novice users. While not a high performer, the Equity was a reliable and compatible design for half the price of a similarly-configured IBM PC. Epson often promoted sales by bundling one of their printers with it at cost. The Equity I sold well enough to warrant the furtherance of the Equity line with the follow-on Equity II, Equity III, and others based on the i386SX.
In 1986 UK home computer maker
Amstrad began producing their
 PC-compatible for sale in the UK. Later they would market the machine in the USA as the PC6400. In June 1987 an improved model was produced as the PC1640. These machines had fast
8086 CPUs, enhanced
CGA graphics, and were feature-laden for their modest prices. They had joystick adapters built into their keyboards and shipped with a licensed version of the
Graphical Environment Manager (or GEM), a
GUI for the MS-DOS operating system. They became marginal successes in the home market. For a short time Amstrad also marketed a home-computer style PC with an RF modulator for use with a television set display. This was the
PC20, also as the Sinclair PC200.
In 1987 longtime small computer maker
Zenith introduced a low-cost PC they called the eaZy PC.
 This was positioned as an "appliance" computer much like the original Apple Macintosh: turnkey startup, built-in monochrome monitor, and lacking expansion slots requiring proprietary add-ons available only from Zenith, but instead with the traditional MS-DOS
Command-line interface. The eaZy PC used a turbo NEC V40 CPU (uprated 8088) which was rather slow for its time, but the display did feature 400 pixel vertical resolution (double-scanned CGA in text mode only). It failed for the same reasons as did IBM's PCjr: poor performance and expandability, and an uncompetetive price for the home market.
Another company that offered low-cost PCs for home use was
Leading Edge with their Model M and
Model D computers. These were configured like full-featured business PCs yet still could compete in the home market on price because Leading Edge had access to low-cost hardware from their Asian manufacturing partners
Mitsubishi with the Model M and
Daewoo with the Model D. The
Leading Edge Word Processor was bundled with the Model D. It was favorably reviewed by the computer press and sold very well.
 Still another budget offering from Korea was the
Hyundai Blue Chip PC-XT clone, which was sold through Target, Sears, and Wal-Mart department stores.
By the mid-80s the market for inexpensive PCs for use in the home market was expanding at a rate such that the two leaders in the USA,
Commodore and Atari, themselves felt compelled to enter the market with their own lines. They were only marginally successful compared to other companies that made only PCs.
Still later prices of
white box PC clone computers by various manufacturers became competitive with the higher-end home computers (see below). Throughout the 1980s costs and prices continued to be driven down by: advanced circuit design and manufacturing, multifunction expansion cards,
shareware applications such as
PC-File, greater hardware reliability, and more user-friendly software that demanded less customer support services. The increasing availability of faster processor and memory chips, inexpensive
VGA video cards,
sound cards, and joystick adapters also bolstered the viability of PC/DOS computers as alternatives to specially-made computers and game consoles for the home.
68000s Come Home (June 1985 to early 1986)
The Fifth, last wave of computers specially meant for use as home computers arrived in June 1985 with the
Atari ST. Soon after, but unavailable until 1986, came Commodore's
Amiga. These new machines were an entirely new breed built around Motorola's 16/32-bit
68000 processor, the same as used in Apple's expensive Macintosh and premature Sinclair QL. This chip promised superior performance due to its advanced architecture and fast clock rate, made possible by fast yet inexpensive memory chips. Also, the 68000 could access megabytes of memory linearly, without any need for Intel's segmented memory model. This made huge, sophisticated programs possible. Both machines used the new 3.5 inch floppy drives offering four times the storage of the 5.25 inch drives. The user interface used was graphical, like the Macintosh. The ST used a licensed version of Digital Research's
GEM and the Amiga's original GUI featured true multitasking and windowing capability. The video hardware in these two computers could render graphics in hundreds or thousands of colors in high resolution. The Amiga had dedicated graphics and sound
coprocessors for high performance video and audio. It found use as a workstation for motion video, a first for a standalone computer costing far less than dedicated motion-video processing equipment. Stereo sound became standard for the first time; the Atari ST gained popularity as an affordable alternative for
MIDI equipment for the production of music.
After a slow start the ST and Amiga gained traction in the market as software developers increased support for them. In following years both lines would be advanced using the faster, fully 32-bit successors of the Motorola 68000 CPU.
In June 1987 a computer appeared in the UK which can be considered a member of this wave; this was the
Acorn Archimedes. Because it used Acorn's own
ARM architecture processor rather than the Motorola 68000, it offered superior performance to the ST and Amiga (about double) and likewise was ahead of its time. The Archimedes gained share in the UK educational market but, like the Atari ST and Commodore Amiga, was crowded out in the 1990s by inexpensive PCs running Microsoft Windows with similar multimedia capability.
The 8-bit Swan Song During this period, three venerable 8-bit computers made something of a comeback, if short-lived. These were the
Commodore 128 in January 1985 (and its variant C-128D a bit later), the Radio Shack
Color Computer 3 in July 1986, and the
Apple IIGS (whose CPU is a full 16-bit processor) in September 1986. They incorporated features typical of business-class computers like expanded memory beyond 64 kilobytes, 80 column text screens, higher resolution graphics with more colors, and in the case of the IIGS a Macintosh-like graphical interface. The C-128 had a Z80 chip for
CP/M compatibility and the C-128D a PC-style case with an internal disk drive that could read and write data to PC disks. The new Coco could run a windowing, multitasking operating system called
OS-9. Yet these updated veterans offered full compatibility with the software of their ancestors. Eventually these three, like all the other home computers, were eclipsed by the PCs due to constantly falling prices for the newer technologies. The three companies that opened the 8-bit home computer era in 1977, Tandy/Radio Shack, Apple, and Commodore, at last closed it.
Also noteworthy during this time (September 1985) was the
Amstrad PCW. This was Z80-based and ran CP/M-80, tailored and marketed specifically as a word processing machine (with bundled printer) available at a remarkably low price. While not introducing new technology apart from its 3.0 inch floppy drives and 90 column by 32 line video display, with time it grew to be a popular (especially in the UK and Europe) general-purpose CP/M system running many kinds of applications besides its bundled word processor,
Locoscript. It sold some 8 million units during its market lifespan of more than a decade.