List of early microcomputers - AbsoluteAstronomy.com

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

Microcomputer

A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...

s were often sold as "DIY

Do it yourself

Do it yourself is a term used to describe building, modifying, or repairing of something without the aid of experts or professionals...

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

Microprocessor

A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

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

Random-access memory

Random access memory is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time. Strictly speaking, modern types of DRAM are therefore not random access, as data is read in...

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

Commodore PET

The Commodore PET was a home/personal computer produced from 1977 by Commodore International...

, TRS-80

TRS-80

TRS-80 was Tandy Corporation's desktop microcomputer model line, sold through Tandy's Radio Shack stores in the late 1970s and early 1980s. The first units, ordered unseen, were delivered in November 1977, and rolled out to the stores the third week of December. The line won popularity with...

and Apple II

Apple II

The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...

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

Home computer

Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly 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...

era that followed.

Discrete logic

Before the advent of microprocessors, it was possible to build small scaled computers using small-scale integrated circuit

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

s. A small number of such kits were designed and offered.

The Kenbak-1
Kenbak-1
The Kenbak-1 is considered by the Computer History Museum and the American Computer Museum to be the world's first "personal computer" . Only 40 machines were ever built and sold. It was designed and invented by John Blankenbaker of Kenbak Corporation in 1970, and was first sold in early 1971. The...

(1971) used discrete transistor-transistor logic
Transistor-transistor logic
Transistor–transistor logic is a class of digital circuits built from bipolar junction transistors and resistors. It is called transistor–transistor logic because both the logic gating function and the amplifying function are performed by transistors .TTL is notable for being a widespread...

ICs and had 256 bytes of memory. It was priced at USD 750 and sold only 40 units.
The Educ-8
Educ-8
The EDUC-8, pronounced "educate", was an early microcomputer kit published by Electronics Australia in a series of articles starting in August 1974 and continuing to August 1975. Electronics Australia initially believed that it was the first such kit, but later discovered that Radio-Electronics had...

(1975) was an Electronics Australia
Electronics Australia
Electronics Australia was Australia's longest-running general electronics magazine.It can claim to trace its history to 1922 when the Wireless Weekly magazine was formed. Its content was a mix of general and technical articles on the new topic of radio....

magazine project describing a computer built from TTL ICs.

Test and development machines

As microprocessors were released into the market, companies often released simple development systems to bootstrap the use of the processor. These systems were often converted by hobbyists into complete computer systems.

This is a sortable list; click on the icon at the top of each column to sort by the contents of that column.
! Model
Processor	Year	Format	Remarks	Ref
Intel SIM8-01	Intel 8008 Intel 8008 The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory...	early 1972	bare board	Intel's developer kit for the 8008
MOS Technology KIM-1 KIM-1 The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976...	MOS Technology 6502 MOS Technology 6502 The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...	1975	complete board	MOS's developer kit for the 6502, widely used in a number of projects
Motorola Motorola Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009... MEK6800D2 MEK6800D2 The MEK6800D2 was a development board for the Motorola 6800 microprocessor, produced by Motorola in 1976. It featured a keyboard with hexadecimal keys and a LED display, but also featured an RS-232 asynchronous serial interface for a Teletype or other terminal...	Motorola 6800 Motorola 6800 The 6800 was an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips...	1976	complete board
Rockwell AIM-65 AIM-65 The Rockwell AIM-65 computer was a development computer based on the MOS Technology 6502 microprocessor introduced in 1976. The AIM-65 was essentially an expanded KIM-1 computer. Available software included a monitor with line at a time assembler/disassembler, BASIC interpreter, assembler, Pascal,...	6502		complete board
Synertek SYM-1 SYM-1 The SYM-1 was a single board "trainer" computer produced by Synertek circa 1978. Originally called the VIM-1 , that name was changed for legal reasons sometime between April and August 1978....	6502	1978	complete board
Intel SDK-85	Intel 8085 Intel 8085 The Intel 8085 is an 8-bit microprocessor introduced by Intel in 1977. It was binary-compatible with the more-famous Intel 8080 but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built....	1978

Kits

For some time the microcomputer world was dominated by systems delivered in kit form. As most machines of the era were sold in small numbers, there was no reason to invest in automated manufacturing systems, leaving the final assembly to manual labor. Kits took advantage of this by offering the system at a low price point, and relying on the user to complete the expensive part, the final assembly. Kits were popular between 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 famed ZX81 is among the last of the large sellers in the kit market.

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.

This is a sortable list; click on the icon at the top of each column to sort by the contents of that column.
! Model
Processor	Year	Format	Remarks	Ref
SCELBI SCELBI SCELBI Computer Consulting was a personal-computer hardware and software manufacturer located in Milford, Connecticut. It was founded in 1973 by Nat Wadsworth and Bob Findley. Initially, they sold hardware based on the first 8-bit microprocessor from Intel, the 8008...	Intel 8008 Intel 8008 The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory...	1974		was the earliest commercial kit computer based on the Intel 8008 Intel 8008 The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory... microprocessor. sold for embedded control applications.
Mark-8 Mark-8 The Mark-8 is a microcomputer design from 1974, based on the Intel 8008 CPU . The Mark-8 was designed by graduate student Jonathan Titus and announced as a 'loose kit' in the July 1974 issue of Radio-Electronics magazine.- Project kit :The Mark-8 was introduced as a 'build it yourself' project in...	Intel 8008	1974	Plans published, an etched board was available but constructors had to source all parts
MITS Altair 8800 Altair 8800 The MITS Altair 8800 was a microcomputer design from 1975 based on the Intel 8080 CPU and sold by mail order through advertisements in Popular Electronics, Radio-Electronics and other hobbyist magazines. The designers hoped to sell only a few hundred build-it-yourself kits to hobbyists, and were...	Intel 8080 Intel 8080 The Intel 8080 was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It was an extended and enhanced variant of the earlier 8008 design, although without binary compatibility...	1975	Etched boards and parts	introduced S-100 bus S-100 bus The S-100 bus or Altair bus, IEEE696-1983 , was an early computer bus designed in 1974 as a part of the Altair 8800, generally considered today to be the first personal computer...
COSMAC ELF COSMAC ELF The COSMAC ELF was an RCA 1802 microprocessor-based computer based on a series of construction articles in Popular Electronics magazine in 1976 and 1977. Through the back pages of electronics magazines, both Netronics and Quest Electronics offered low-priced kits that were based on this design. ...	RCA 1802 RCA 1802 The RCA CDP1802, also known as the COSMAC , is an 8-bit CMOS microprocessor introduced by RCA in early 1976. It is being by Intersil Corporation as a high-reliability microprocessor...	1976
Apple I Apple I The original Apple Computer, also known retroactively as the Apple I, or Apple-1, is a personal computer released by the Apple Computer Company in 1976. They were designed and hand-built by Steve Wozniak. Wozniak's friend Steve Jobs had the idea of selling the computer...	MOS Technology 6502 MOS Technology 6502 The MOS Technology 6502 is an 8-bit microprocessor that was designed by Chuck Peddle and Bill Mensch for MOS Technology in 1975. When it was introduced, it was the least expensive full-featured microprocessor on the market by a considerable margin, costing less than one-sixth the price of...	1976
Nascom Nascom The Nascom 1 and 2 were single-board computer kits issued in 1977 and 1979, respectively, based on the Zilog Z80 and including a keyboard and video interface, a serial port that could be used to store data on a tape cassette using the Kansas City standard, and two 8-bit parallel ports... , Nascom 1	Zilog Z80 Zilog Z80 The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...	1977
Nascom 2	Z80	1979
Newbear 77-68	Motorola 6800 Motorola 6800 The 6800 was an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips...	1977
Heathkit H8 Heathkit H8 Heathkit's H8 was an Intel 8080-based microcomputer sold in kit form starting in 1977. The H8 was similar to the S-100 bus computers of the era, and like those machines was often used with the CP/M operating system on floppy disk...	8080	1977	all parts, case and power supply, detailed instructions	Heathkit Heathkit Heathkits were products of the Heath Company, Benton Harbor, Michigan. Their products included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, electronic ignition conversion modules for early model cars with point style ignitions, and... was a notable manufacturer of electronics kits
Heathkit H11	LSI-11	1977	all parts, case and power supply, detailed instructions	A 16-bit microcomputer compatible with a PDP 11
Electronics Australia Electronics Australia Electronics Australia was Australia's longest-running general electronics magazine.It can claim to trace its history to 1922 when the Wireless Weekly magazine was formed. Its content was a mix of general and technical articles on the new topic of radio.... 77up2 aka "Baby 2650	2650 Signetics 2650 The Signetics 2650, was a very early 8-bit microprocessor. According to Adam Osborne's classic book An Introduction to Microprocessors Vol 2: Some Real Products, it was "the most minicomputer-like" of the microprocessors available at the time....	1977
Netronics ELF II ELF II The Netronics ELF II was an early microcomputer trainer kit introduced about 1977 featuring an RCA 1802 microprocessor, 256 bytes of RAM, 0 bytes of ROM, DMA-based bitmap graphics, hex keypad for user interaction and DMA based program loading, a two digit hexadecimal LED display, an LED on the...	RCA 1802 RCA 1802 The RCA CDP1802, also known as the COSMAC , is an 8-bit CMOS microprocessor introduced by RCA in early 1976. It is being by Intersil Corporation as a high-reliability microprocessor...	1977
Quest SuperELF	RCA 1802 RCA 1802 The RCA CDP1802, also known as the COSMAC , is an 8-bit CMOS microprocessor introduced by RCA in early 1976. It is being by Intersil Corporation as a high-reliability microprocessor...
Elektor TV Games Computer Elektor TV Games Computer The Elektor TV Games Computer was a programmable computer system sold by Elektor in kit form from 1979. It used the Signetics 2650 CPU with the Signetics 2636 PVI for graphics and sound. These were the same chips as used in the Interton VC 4000 console family...	Signetics 2650 Signetics 2650 The Signetics 2650, was a very early 8-bit microprocessor. According to Adam Osborne's classic book An Introduction to Microprocessors Vol 2: Some Real Products, it was "the most minicomputer-like" of the microprocessors available at the time....	1979
System 68	Motorola 6800	1977	Electronics today international Electronics today international (magazine) Electronics Today International or ETI was a magazine for electronics hobbyists and professionals.Originally started in Australia in 1971, ETI was published in the UK in 1972. From there, it expanded to various European countries and over to Canada.... magazine project
PSI comp 80 PSI Comp 80 (computer) In 1979, the British magazine Wireless World published the technical details for a "Scientific Computer". Shortly afterward the British firm Powertran used this design for their implementation, which they called the PSI Comp 80...	Z80	1979		by Powertran from a design in the magazine Wireless World Wireless World Wireless World was the pre-eminent British magazine for radio and electronics enthusiasts. It was one of the very few "informal" journals which were tolerated as a professional expense.- History :...
Science of Cambridge MK14 MK14 The Microcomputer Kit 14, or MK14 was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for UK£39.95. The MK14 eventually sold over 50,000 units. It used a National Semiconductor SC/MP CPU , 256 bytes of random access memory which was directly expandable...	National Semiconductor SC/MP National Semiconductor SC/MP The SC/MP from National Semiconductor is an early microprocessor, which became available in early 1974. The name SC/MP is an acronym for: "Simple Cost-effective Micro Processor".It features a 16-bit address and an 8-bit data bus...	1978		Low-cost kit expandable to video output
Tangerine Tangerine Computer Systems British microcomputer company Tangerine Computer Systems was founded in 1979 by Dr. Paul Johnson, Mark Rainer and Nigel Penton Tilbury in St. Ives, Cambridgeshire... Microtan 65 Tangerine MICROTAN 65 The Tangerine Microtan 65 was a 6502 based single board microcomputer, first sold in 1979, which could be expanded into, what was for its day, a comprehensive and powerful system. The design became the basis for what later became the ORIC, ATMOS and later computers, which had similar keyboard...	6502	1979		Rack-based extendible system
Sinclair's ZX80	Z80	1980		were among the last popular kit systems
Sinclair ZX81	Z80	1981		were among the last popular kit systems

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, Apple II

Apple II

, and Commodore PET

Commodore PET

The Commodore PET was a home/personal computer produced from 1977 by Commodore International...

, significantly changed the market and led to the home computer

Home computer

revolution.

Datapoint 2200
Datapoint 2200
The Datapoint 2200 was a mass-produced programmable terminal, designed by Phil Ray and Gus Roche, announced by Computer Terminal Corporation in June, 1970...

of 1970 (shipping 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.
MicroSystems International
MicroSystems International
Microsystems International Limited was a telecommunications microelectronics company based in Ottawa, founded in 1969. MIL was an early attempt to create a merchant semiconductor house by Nortel Networks...

's CPS-1, using a locally produced microprocessor based on the design of the Intel 4004
Intel 4004
The Intel 4004 was a 4-bit central processing unit released by Intel Corporation in 1971. It was the first complete CPU on one chip, and also the first commercially available microprocessor...

. First built in 1972, a small number shipped in early 1973.
Micral N
MICRAL
According to the Computer History Museum, the Micral N, produced by the French company R2E, was the earliest commercial, non-kit personal computer based on a microprocessor...

(1973) was the earliest commercial, non-kit personal computer based on a microprocessor (the Intel 8008
Intel 8008
The Intel 8008 was an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It was an 8-bit CPU with an external 14-bit address bus that could address 16KB of memory...

)
MCM/70
MCM/70
The MCM/70 was a pioneering microcomputer first built in 1973 and released the next year, making it one of the first microcomputers in the world, the second to be shipped in completed form, the first portable computer, and arguably the first truly usable microcomputer system...

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.
Processor Technology
Processor Technology
Processor Technology Corporation was a microcomputer company founded by Bob Marsh and Gary Ingram in April 1975. Its best known product is the Sol-20 computer.-History:...

's Sol-20, offered both as kit and assembled, but the vast majority were sold assembled
ECD Micromind, introduced 1977 MOS Technology 6512
MOS Technology
MOS Technology, Inc., also known as CSG , was a semiconductor design and fabrication company based in Norristown, Pennsylvania, in the United States. It is most famous for its 6502 microprocessor, and various designs for Commodore International's range of home computers.-History:MOS Technology, Inc...

(6502 w/ external clock). Prototypes only.
Tesla PMI-80
PMI-80
The PMI-80 was a primitive single-board microcomputer produced by Tesla Piešťany, Czechoslovakia, since 1982. It was based on the MHB 8080A CPU , clocked at 1 MHz. Instead of a monitor output, it had a nine-digit seven-segment red LED display showing hexadecimal numbers. The keyboard was a 25-key...
Ohio Scientific
Ohio Scientific
Ohio Scientific Inc. was a United States computer company that built and marketed computers from the late 1970s to the early 1980s...

Model 500, 1978, 6502
Explorer/85
Explorer/85
The Netronics Explorer 85 was a Intel 8085 based computer produced by Netronics R&D Ltd. located in New Milford, Connecticut between 1979 and 1984. Netronics also produced the more well known ELF II computer, and the ill fated Explorer 88 computer....

8085, 1979

External links

Obsolete technology website — Information about many old computers.

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Discrete logic

Test and development machines

Kits

Complete microcomputers

See also

External links