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 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.
ModelProcessorYearFormatRemarksRef
Intel SIM8-01Intel 8008early 1972bare boardIntel's developer kit for the 8008
MOS Technology KIM-1MOS Technology 65021975complete boardMOS's developer kit for the 6502, widely used in a number of projects
Motorola MEK6800D2Motorola 68001976complete board
Rockwell AIM-6565021978 complete board
Synertek SYM-165021978complete board
Intel SDK-85Intel 80851978

Kits

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.
ModelProcessorYearFormatRemarksRef
SCELBIIntel 80081974Was the earliest commercial kit computer based on the Intel 8008 microprocessor. sold for embedded control applications.[2]
Mark-8Intel 80081974Plans published, an etched board was available but constructors had to source all parts[3]
MITS Altair 8800Intel 80801975Etched boards and partsIntroduced S-100 bus
COSMAC ELFRCA 18021976
Apple IMOS Technology 65021976Assembled PCB; buyer supplied rest of components
Nascom, Nascom 1Zilog Z801977
Nascom 2Z801979
Telmac 1800RCA 18021977
Newbear 77-68Motorola 68001977
Heathkit H8intel 80801977All parts, case and power supply, detailed instructionsHeathkit was a notable manufacturer of electronics kits
Heathkit H11LSI-111977All parts, case and power supply, detailed instructionsA 16-bit microcomputer compatible with a PDP 11
Electronics Australia 77up2 aka "Baby 265026501977
Netronics ELF IIRCA 18021977
Quest SuperELFRCA 18021974
Elektor TV Games ComputerSignetics 26501979
System 68Motorola 68001977Electronics today international magazine project
PSI comp 80Z801979By Powertran from a design in the magazine Wireless World
Science of Cambridge MK14National Semiconductor SC/MP1978Low-cost kit expandable to video output[4]
Acorn System 165021979
Tangerine Microtan 6565021979Rack-based extendible system
Compukit UK10165021979Practical Electronics magazine project (Clone of Ohio Scientific Superboard II)BASIC in ROM
Sinclair's ZX80Z801980Were among the last popular kit systems
Sinclair ZX81Z801981Were among the last popular kit systems
MicroBeeZilog Z801982The computer was conceived as a kit, with assembly instructions included in Your Computer magazine, in February 1982.[5]

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

  • MicroSystems International's CPS-1, using a locally produced microprocessor based on the design of the Intel 4004. First built in 1972, a small number shipped in early 1973.[6]
  • 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.[7]
  • Sord Computer Corporation's SMP80/08, based on the Intel 8008, 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.[8]
  • MCM/70 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.[9]
  • IBM 5100 was possibly the first portable microcomputer. Most people think the famous IBM PC (the 5150) was IBM's first micro but there were a number of microcomputer models released by IBM from 1975.
  • Processor Technology's Sol-20, 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.[10] As of 2011, the MPT8080 was still available for sale.
  • Tesla PMI-80
  • Ohio Scientific Model 500, 1978, 6502
  • Exidy Sorcerer, 1978, Z80
  • Explorer/85 8085, 1979
  • ComPAN 8 was a Polish microcomputer in the 1980’s designed in the Institute of Industry Automation Systems PAN in Gliwice and produced in the MERA-ELZAB factory in Zabrze.[11][12]

See also

References
  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. inventors.about.com
  3. p. 4/8, A history of the personal computer: the people and the technology, Roy A. Allan, 2001, ISBN 0-9689108-0-7.
  4. http://www.nvg.ntnu.no/sinclair/computers/mk14/mk14_pe0579.htm "Science of Cambridge MK14", May 1979, retrieved 2011 July 2
  5. Microbee computer, From:Owen Hill Date:24 Aug 1998, Link list on Australian network policy and communications
  6. Zbigniew Stachniak, "The MIL MF7114 Microprocessor", IEEE Annals of Computer History, 22 September 2009, pg. 48-59
  7. Computer History Museum
  8. http://museum.ipsj.or.jp/en/computer/personal/0086.html
  9. Zbigniew Stachniak. "The Making of the MCM/70 Microcomputer". IEEE Annals of the History of Computing, 2003: pg. 62-75
  10. 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.
  11. Komputery - www.nfsk.prv.pl - Notatnik Fana Starych Komputerów Archived 2008-03-02 at the Wayback Machine
  12. Polish Computers Fan Site
Notes
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