List of early microcomputers

This is a list of early microcomputers sold to hobbyists and developers. These microcomputers were often sold as "DIY" kits or pre-built machines in relatively small numbers in the mid-1970s. These systems were primarily used for teaching the use of microprocessors 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 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, TRS-80 and Apple II 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.

Test, single-board 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 microcomputers Intel produced starting in the 1970s as a development platform for their processors.

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 early 1972 bare board Intel's developer kit for the 8008
MOS Technology KIM-1 MOS Technology 6502 1975 complete board MOS's developer kit for the 6502, widely used in a number of projects
Motorola MEK6800D2 Motorola 6800 1976 complete board
MPT8080 Microtutor Intel 8080 1977 complete board A trainer type single-board-computer. As recently as 2008, it remained in academic use. [2] As of 2011, the MPT8080 was still available for sale.
Rockwell AIM-65 6502 1978 complete board
Synertek SYM-1 6502 1978 complete board
Intel SDK-85 Intel 8085 1978
Tesla PMI-80 Intel 8080 clone 1982 complete board A czechoslovakiand single-board microcomputer.



Many early microcomputers were available in Electronic kit 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 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.

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 Intel 8008 1974 Was the earliest commercial kit computer based on the Intel 8008 microprocessor. Sold for embedded control applications. [3]
Mark-8 Intel 8008 1974 Plans published; an etched board was available but constructors had to source all parts [4]
MITS Altair 8800 Intel 8080 1975 Etched boards and parts Introduced S-100 bus
IMSAI 8080 Intel 8080 1975
Comp-Sultants Micro 440 Intel 4040 1975 First 4040-based micro
SWTPC 6800 Motorola 6800 1975 Introduced SS-50 bus
COSMAC ELF RCA 1802 1976
Apple I MOS Technology 6502 1976 Assembled PCB; buyer supplied rest of components
Nascom, Nascom 1 Zilog Z80 1977
Nascom 2 Z80 1979
Telmac 1800 RCA 1802 1977
Newbear 77-68 Motorola 6800 1977
Heathkit H8 Intel 8080 1977 All parts, case and power supply, detailed instructions Heathkit 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 77up2 aka "Baby 2650" Signetics 2650 1977
Netronics ELF II RCA 1802 1977
Quest SuperELF RCA 1802 1974
Elektor TV Games Computer Signetics 2650 1979
System 68 Motorola 6800 1977 Electronics Today International magazine project
PSI comp 80 Z80 1979 By Powertran from a design in the magazine Wireless World
Science of Cambridge MK14 National Semiconductor SC/MP 1978 Low-cost kit expandable to video output [5]
Acorn System 1 6502 1979
Tangerine Microtan 65 6502 1979 Rack-based extendible system
Compukit UK101 6502 1979 Practical Electronics magazine project (clone of Ohio Scientific Superboard II) BASIC in ROM
Sinclair ZX80 Z80 1980 Among the last popular kit systems
Sinclair ZX81 Z80 1981 Among the last popular kit systems
MicroBee Zilog Z80 1982 The computer was conceived as a kit, with assembly instructions included in Your Computer magazine, in February 1982. [6]
The Digital Group Zilog Z80 1975 Kits or assembled PCBs. Including cases from 1978 The first company to produce mostly complete systems built around the Zilog Z80 processor. Their products also included options for MOS 6502 and Motorola 6800 processors.

Complete microcomputers


A number of complete microcomputers were offered even before kits became popular, dating to as far back as 1972. 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, and Commodore PET, significantly changed the American microcomputer market and led to the home computer revolution.

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 Remarks Ref
Q1 Corporation, Q1 Intel 8008 1972 The first general purpose microcomputer to ship with a built in alphanumeric user interface. First sold in December 72. [7]
MicroSystems International CPS-1 MIL MF7114 1972 Using a locally produced microprocessor based on the design of the Intel 4004. First built in 1972, a small number shipped in early 1973. [8] [9]
Micral N 1973 Awarded the title of "the first personal computer using a microprocessor" by a panel at the Computer History Museum in 1986. [10]
Sord Computer Corporation SMP80/08 Intel 8008 1974 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. [11]
MCM/70 Intel 8008 1974 Primarily designed to run APL. According to the IEEE Annals of Computer History, the MCM/70 is the earliest commercial, non-kit personal computer. [12]
IBM 5100 1975 An early portable computer with integrated monitor; the 5100 was possibly one of the first portable microcomputers using a CRT display.
Sphere 1 1975 A 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 Sol-20 1976 Offered both as kit and assembled, but the vast majority were sold assembled.
Tandberg Radiofrabrikk/Tandberg Data TDV-2114 Intel 8080 1976 One of the first all-in-one microcomputers developed in Europe. It was sold as a complete package, with CPU-module, Memory-modules and a 8" floppy-disk drive w/module all built into a case with a TDV-2115 dumb-terminal. It was initially marketed towards businesses as an "intelligent terminal" and workstation, running Tandberg-OS (having the look and feel of Intel ISIS-II). After the separation of Tandberg Data, this machine would also be available in OEM form as the Siemens System 6.610. [13][14][15]
Radio Shack TRS-80 Zilog Z80 1977 Mainly targeting North America, it was very popular as a home computer.
Apple II 6502 1977 Quickly became the leading business desktop workstation with software such as VisiCalc, but also somewhat popular as a home computer. Initially only available in the US, but would eventually be available worldwide.
Commodore PET 6502 1977 Most popular as an educational computer used in schools, but some success as a business or academic workstation too. Later, the PET would eventually see limited popularity in Europe.
ECD Micromind MOS Technology 6512 1977
Ohio Scientific Model 500 6502 1978
Exidy Sorcerer Z80 1978
Atlacatl Home Computer MOS Technology 6502 1979 A Salvadoran-made microcomputer based in locally sourced (from Texas Instruments Soyapango factory) processors at 2 MHz, TMC0280 Voice synthesizer, TMS9918 Video Interface with genlock capability and starting at 32 KB of DRAM, originally announced in January 1979 and launched after several delays in manufacturing in Christmas season of that year, proved popular in the country mostly with their Atlacatl Monica accounting software and TV-compatible output with genlock capabilities was used extensively by low-budget TV stations in Central America until around 1985; the company went bankrupt in 1989 after the end of draconian import regulations.
Explorer/85 8085 1979
ComPAN 8 1980 Designed in the Institute of Industry Automation Systems PAN in Gliwice and produced in the MERA-ELZAB factory in Zabrze. [16][17]

See also



  1. ^ p. 4/3, A history of the personal computer: the people and the technology, Roy A. Allan, 2001, ISBN 0-9689108-0-7.
  2. ^ Department of Physics (2008-10-06). "Machine code programming". Second Year Physics Laboratory Manual 2008/2009 (PDF). University of London. p. 54. Retrieved 2011-03-03.
  3. ^ [1]
  4. ^ p. 4/8, A history of the personal computer: the people and the technology, Roy A. Allan, 2001, ISBN 0-9689108-0-7.
  5. ^ "Science of Cambridge MK14", May 1979, retrieved 2011 July 2
  6. ^ Microbee computer, From:Owen Hill Date:24 Aug 1998, Link list on Australian network policy and communications
  7. ^ "The Byte Attic: Q1™". 2022-09-08.
  8. ^ Zbigniew Stachniak, "The MIL MF7114 Microprocessor", IEEE Annals of Computer History, 22 September 2009, pg. 48-59
  9. ^ "MIL CPS-1 Emulator". York University Computer Museum. 2023. Retrieved 2024-02-03. The CPS-1 computer was developed by Micosystems International Ltd. (MIL) of Ottawa between 1972 and 1973. The CPS-1 was powered by Canada's first microprocessor — the MIL 7114. This computer is one of the world's first commercially available microprocessor-based computer.
  10. ^ Computer History Museum
  11. ^ "SMP80/X series-Computer Museum".
  12. ^ Zbigniew Stachniak. "The Making of the MCM/70 Microcomputer". IEEE Annals of the History of Computing, 2003: pg. 62-75
  13. ^ Historielaget Grefsen-Kjelsås-Nydalen (2012-11-20). "En norsk datahistorie fra Kjelsås".
  14. ^ "Tandberg Data Newsletter, Vol.5 Nr.1" (Document). Tandberg Data. June 1982. p. 4.
  15. ^ "Siemens Intern, 1979 Nr.3" (Document). Siemens A/S. 1979-10-09. p. 8.
  16. ^ Komputery - - Notatnik Fana Starych Komputerów Archived 2008-03-02 at the Wayback Machine
  17. ^ Polish Computers Fan Site