This is a list of early microcomputers sold to hobbyists and developers. These

microcomputer A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (P ...

s were often sold as "

DIY "Do it yourself" ("DIY") is the method of building, modifying, or repairing things by oneself without the direct aid of professionals or certified experts. Academic research has described DIY as behaviors where "individuals use raw and sem ...

" kits or pre-built machines in relatively small numbers in the mid-1970s. These systems were primarily used for teaching the use of

microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...

s and supporting peripheral devices, and unlike home computers were rarely used with pre-written application software. Most early micros came without alphanumeric keyboards or displays, which had to be provided by the user.

RAM Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch ...

was quite small in the unexpanded systems (a few hundred bytes to a few kilobytes). By 1976 the number of pre-assembled machines was growing, and the 1977 introduction of the "Trinity" of

Commodore PET The Commodore PET is a line of personal computers produced starting in 1977 by Commodore International. A single all-in-one case combines a MOS Technology 6502 microprocessor, Commodore BASIC in read-only memory, keyboard, monochrome monitor, ...

TRS-80 The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of ...

and

Apple II The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-mold ...

generally marks the end of the "early" microcomputer era, and the advent of the consumer home computer era that followed.

Discrete logic

Before the advent of microprocessors, it was possible to build small computers using small-scale integrated circuits (ICs), where each IC contained only a few logic gates or flip-flops. * The

Kenbak-1 The Kenbak-1 is considered by the Computer History Museum, the Computer Museum of America and the American Computer Museum to be the world's first "personal computer", invented by John Blankenbaker (born 1929) of Kenbak Corporation in 1970, and f ...

(1971) used

small scale integration An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Transistor count, Large ...

transistor-transistor logic (TTL) ICs and had 256 bytes of memory. It was priced at USD 750 and sold only 40 units. *

Datapoint 2200 The Datapoint 2200 was a mass-produced programmable computer terminal usable as a computer, designed by Computer Terminal Corporation (CTC) founders Phil Ray and Gus Roche and announced by CTC in June 1970 (with units shipping in 1971). It was ...

(shipped 1971) was the first machine ''designed'' to use a microprocessor, but when Intel could not deliver the 8008 in time, they released the machine using discrete logic. * The Educ-8 (1975) was an ''

Electronics Australia ''Electronics Australia'' or ''EA'' was Australia's longest-running general electronics magazine. It was based in Chippendale, New South Wales. Publication history It can claim to trace its history to 1922 when the ''Wireless Weekly'' magazine ...

'' magazine project describing a computer built from TTL ICs.

Test and development machines

As microprocessors were developed, companies often released simple development systems to bootstrap the use of the processor. These systems were often converted by hobbyists into complete computer systems. Intel's Intellec computers were a series of early

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the devel ...

produced starting in the 1970s as a development platform for their processors.

Kits

Many early microcomputers were available in

Electronic kit An electronic kit is a package of electrical components used to build an electronic device. Generally, kits are composed of electronic components, a circuit diagram (schematic), assembly instructions and often a printed circuit board (PCB) or ...

form. Machines were sold in small numbers, with final assembly by the user. Kits took advantage of this by offering the system at a low price point. Kits were popular, beginning in 1975, with the introduction of the famous Altair 8800, but as sales volumes increased, kits became less common. The introduction of useful fully assembled machines in 1977 led to the rapid disappearance of kit systems for most users. The

ZX81 The ZX81 is a home computer that was produced by Sinclair Research and manufactured in Dundee, Scotland, by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and designed to be a low-c ...

was one of the last systems commonly available in both kit and assembled form. Some magazines published plans and printed circuit board layouts from which a reader could in principle duplicate the project, although usually commercially made boards could be ordered to expedite assembly. Other kits varied from etched, drilled, printed circuit boards and a parts list to packages containing cases, power supplies, and all interconnections. All kits required significant assembly by the user.

Complete microcomputers

A number of complete microcomputers were offered even before kits became popular, dating to as far back as 1973. For some time there was a major market for assembled versions of the Altair 8800, a market that grew significantly through the late 1970s and into the early 1980s. The introduction of three computers aimed at personal users in 1977, the Radio Shack TRS-80,

, and

, significantly changed the market and led to the home computer revolution. *

MicroSystems International Microsystems International Limited (MIL) was a telecommunications microelectronics company based in Ottawa, Ontario, Canada, founded in 1969. MIL was an early attempt to create a merchant semiconductor house by Nortel Networks (then Northern Elect ...

's CPS-1, using a locally produced microprocessor based on the design of the

Intel 4004 The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. Sold for US$60, it was the first commercially produced microprocessor, and the first in a long line of Intel CPUs. The 4004 was the first signific ...

. First built in 1972, a small number shipped in early 1973. * Micral N (1973) was awarded the title of "the first personal computer using a microprocessor" by a panel at the Computer History Museum in 1986.Computer History Museum *

Sord Computer Corporation } Sord Computer Corporation is a Japanese electronics company, founded in 1970 by the entrepreneur Takayoshi Shiina. From 1985 until 2018, it was a subsidiary of Toshiba and became known variously as Toshiba Personal Computer System Corporation an ...

's SMP80/08, based on the

Intel 8008 The Intel 8008 ("''eight-thousand-eight''" or "''eighty-oh-eight''") is an early byte-oriented microprocessor designed by Computer Terminal Corporation (CTC), implemented and manufactured by Intel, and introduced in April 1972. It is an 8-bit CP ...

, was announced in early 1973, but never commercially released. It was followed by the SMP80/x, which debuted in May 1974 and used the

Intel 8080 The Intel 8080 (''"eighty-eighty"'') is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compati ...

. *

MCM/70 The MCM/70 was a pioneering microcomputer first built in 1973 in Toronto, Ontario, Canada and released the next year. This makes it one of the first microcomputers in the world, the second to be shipped in completed form, and the first portable com ...

was a 1974 Intel 8008-based design, primarily designed to run APL. According to the IEEE Annals of Computer History, the MCM/70 is the earliest commercial, non-kit personal computer. *

IBM 5100 The IBM 5100 Portable Computer is a portable computer (one of the first) introduced in September 1975, six years before the IBM Personal Computer, and eight before the first successful IBM compatible portable computer, the Compaq Portable. It ...

was an early portable computer with integrated monitor; the 5100 was possibly the first portable microcomputer. Many people think the famous IBM PC (the 5150) was IBM's first micro but there were a number of microcomputer models released by IBM beginning in 1975. *

The Digital Group The Digital Group was the first company to produce a system built around the Zilog Z80 processor. Their hobbyist-targeted products were based on a system of interchangeable boards and components which allowed users to upgrade to different CPUs ...

was the first company to produce mostly complete systems, both as kits and assembled, built around the

Zilog Z80 The Z80 is an 8-bit computing, 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first wor ...

processor in 1975. Their products also included options for

MOS 6502 The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small te ...

and

Motorola 6800 The 6800 ("''sixty-eight hundred''") is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System (latter dubbed ''68xx'') that also included serial and paral ...

processors. The company began providing computer cases in 1978. * Sphere 1, a 1975 personal computer that was among the earliest complete all-in-one microcomputers that could be plugged in, turned on, and be fully functional. *

Processor Technology Processor Technology Corporation was a personal computer company founded in April 1975 by Gary Ingram and Bob Marsh in Berkeley, California. Their first product was a 4K byte RAM board that was compatible with the MITS Altair 8800 computer but mo ...

Sol-20 The Sol-20 was the first fully assembled microcomputer with a built-in keyboard and television output, what would later be known as a home computer. The design was a combination of an Intel 8080-based motherboard, a VDM-1 graphics card, the 3P+S ...

, offered both as kit and assembled, but the vast majority were sold assembled * ECD Micromind, introduced 1977 MOS Technology 6512 (6502 w/ external clock). Prototypes only. * MPT8080 Microtutor, an Intel 8080–based microprocessor trainer introduced 1977. As recently as 2008, it remained in academic use. As of 2011, the MPT8080 was still available for sale. * Tesla

PMI-80 The PMI-80 was a single-board microcomputer produced by Tesla Piešťany, Czechoslovakia, since 1982. It was based on the MHB 8080A CPU (a Tesla clone of the Intel 8080), clocked at 1.111 MHz. Instead of a raster graphic display output and cl ...

Ohio Scientific Ohio Scientific Inc. (also known as Ohio Scientific Instruments) was an Ohio-based computer company that built and marketed microcomputers from 1975 to 1981. Their best-known products were the Challenger series of microcomputers and Superboard sin ...

Model 500, 1978, 6502 *

Exidy Sorcerer The Sorcerer is a home computer system released in 1978 by the video game company Exidy. Based on the Zilog Z80 and the general layout of the emerging S-100 standard, the Sorcerer was comparatively advanced when released, especially when compar ...

, 1978, Z80 * Explorer/85 8085, 1979 *

ComPAN 8 ComPAN 8 is an 8-bit Polish microcomputer produced in the 1980s at the MERA-ELZAB factory in Zabrze, Poland. ComPAN 8 was designed at the Institute of Industry Automation Systems PAN in Gliwice. Technical description * Processor: 8080A or 8085 ...

was a Polish microcomputer in the 1980s designed in the Institute of Industry Automation Systems PAN in

Gliwice Gliwice (; german: Gleiwitz) is a city in Upper Silesia, in southern Poland. The city is located in the Silesian Highlands, on the Kłodnica river (a tributary of the Oder). It lies approximately 25 km west from Katowice, the regional cap ...

and produced in the MERA-ELZAB factory in

Zabrze Zabrze (; German: 1915–1945: ''Hindenburg O.S.'', full form: ''Hindenburg in Oberschlesien'', Silesian: ''Zŏbrze'', yi, זאַבזשע, Zabzhe) is an industrial city in Silesia in southern Poland, near Katowice. The west district of the Sil ...

.Polish Computers Fan Site
/ref>

References

;Notes *A cached copy of the Department of Physics (2008-10-06). "Machine code programming" can be found on the internet archive at: ** https://web.archive.org/web/20100216174218/http://kcl.ac.uk/content/1/c6/02/14/60/2ndyearmanual2008-2009lab1.pdf * {{refend

External links

Obsolete technology website
— Information about many old computers. *List of early microcomputers