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.

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.

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.

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.

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