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 only 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 (1971) used small-scale integration transistor–transistor logic (TTL) ICs and had 256 bytes of memory. It was priced at USD 750 and sold only 40 units.p. 4/3, A history of the personal computer: the people and the technology, Roy A. Allan, 2001, . Datapoint 2200 (shipped 1971) was the first machine designed to use a microprocessor, but when Intel could not deliver the 8008 in time, the machine was released using discrete logic. The EDUC-8 (1975) was an Electronics Australia magazine project describing a computer built from TTL ICs.
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. ModelProcessorYearFormat Remarks RefIntel SIM4-01, SIM4-02Intel 40041971bare boardIntel's developer kit for the 4004. Sold as the "MCS-4 Micro Computer Set".Intel SIM8-01Intel 8008 1972 bare board Intel's developer kit for the 8008. Sold as the "MCS-8 Micro Computer Set". Mycron MYCRO-1 Intel 8080 1974 complete board Single-board computer with CPU, a little RAM, ROM and serial port. Expandable to a full system with a standard double-slot Eurocard backplane and chassis. 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 MicrotutorIntel 80801976 complete board A trainer type single-board-computer. As recently as 2008, it remained in academic use. As of 2011, the MPT8080 was still available for sale.Rockwell AIM-65 65021978 complete board Synertek SYM-1 6502 1978 complete board RCA COSMAC VIP RCA 1802 1978 complete board 2K RAM, 512 byte ROM, cassette and video interfaces Intel SDK-85Intel 8085 1978 kit Tesla PMI-80Intel 8080 clone1982 complete board A Czechoslovak single-board microcomputer.
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. ModelProcessorYearFormat Remarks RefComstar Star System 4Intel 40041972PCB and several chips/cards; optionally expandableIntended for embedded/industrial applications which did not merit a minicomputer. A complete basic system included one PROM board and chip, one RAM board and chip, a CPU module, digital I/O board, power supply, and mounting rack, altogether for $995. Was in use by November 1972 in a paper tape editing system.SCELBI Intel 80081974 Was the earliest commercial kit computer based on the Intel 8008 microprocessor. Sold for embedded control applications.Mark-8Intel 80081974Plans published; an etched board was available but constructors had to source all parts p. 4/8, A history of the personal computer: the people and the technology, Roy A. Allan, 2001, .MITS Altair 8800Intel 80801975PCB, parts, and caseIntroduced S-100 busIMSAI 8080Intel 80801975PCB, parts, and case Comp-Sultants Micro 440Intel 40401975 First 4040-based microSWTPC 6800Motorola 68001975PCB, parts, and case Introduced SS-50 busThe Digital GroupZilog Z801976Kits or assembled PCBs. Including cases from 1978The 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.COSMAC ElfRCA 18021976 Apple IMOS Technology 65021976Assembled PCB; buyer supplied rest of components Processor Technology Sol-20Intel 80801976Offered both as kit and assembled, but the vast majority were sold assembled.Nascom, Nascom 1 Zilog Z80 1977 Nascom 2 Z80 1979 Telmac 1800 RCA 1802 1977 Newbear 77-68Motorola 68001977 Heathkit H8Intel 80801977All parts, case and power supply, detailed instructions Heathkit was a notable manufacturer of electronics kits Heathkit H11LSI-111977All 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 IIRCA 18021977 Quest SuperELFRCA 18021978 Elektor TV Games ComputerSignetics 26501979 System 68Motorola 6800 1977 Electronics Today International magazine project PSI Comp 80Z801979 By Powertran from a design in the magazine Wireless World RGS-008Intel 80081974 By RGS Electronics; the first computer system ever reviewed in Byte Science of Cambridge MK14National Semiconductor SC/MP 1978 Low-cost kit expandable to video output http://www.nvg.ntnu.no/sinclair/computers/mk14/mk14_pe0579.htm "Science of Cambridge MK14", May 1979, retrieved 2011 July 2Acorn System 1 65021979 Tangerine Microtan 65 65021979 Rack-based extendible systemCompukit UK101 65021979 Practical Electronics magazine project (clone of Ohio Scientific Superboard II) BASIC in ROM Sinclair ZX80 Z801980PCB, parts, and case Among the last popular kit systems Sinclair ZX81 Z801981PCB, parts, and caseAmong 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. Microbee computer , From:Owen Hill Date:24 Aug 1998, Link list on Australian network policy and communications
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. ModelProcessorYearRemarks RefSeiko S-500Intel 80081972Programmable desktop calculator marketed as a desktop computer, which could be used as such by connecting other peripherals such as teletypes. Advertised as early as May 1972, just a month after the release of the Intel 8008.