Timeline of Early Classical Computers

For convenient reference, this informal paper presents the timeline of the notable computers during the early history of classical computing in the 20th century. I compiled this timeline due to my interest in the rapidly developing field of quantum computing, to assess what parallels might exist, now and in the future — after all, we’re supposed to learn lessons from history, lest we be doomed to repeat the mistakes of the past.

There is also a section at the end summarizing some of the early application milestones for early classical computers.

What’s not included

This timeline excludes most precursors to modern computing, including Babbage, Jacquard, and anything else prior to Hollerith and his punched cards.

Most of the machines span the period from 1940 to 1977.

The timeline also excludes all more-recent classical computers, including:

They are excluded not because there is nothing interesting in those later machines, but because I was more interested in the early history that got the ball rolling and gave the field its main momentum. My interest is in the dynamics of early innovation for a new field.

Also excluded are real-time embedded computers, such as those used in avionics, including the space program and military programs. They are of course interesting, but not from the perspective of potential applications of quantum computing, at least as currently envisioned.

Also excluded are many interesting technical details such as word size, main memory technology, size, and limits, mass storage technology, size, and limits, I/O capabilities, etc., although some subset of such features might be added to this paper in future revisions. The Wikipedia pages for each classical computer can be consulted for such technical details.


There are a variety of existing timelines for computers online, but none had the conciseness and specific essential detail that I was looking for, so I cobbled my list together from various sources. In general, each entry in my timeline links to a Wikipedia page for that particular computer.

A few of my sources:

Specific choices of machines to highlight was in part based on my own knowledge and experience.

An earlier version of this timeline was included in an earlier paper of mine:

The timeline in this paper will replace that earlier timeline.

Timeline of early classical computers

Just about every one of the machines on this list was a significant milestone of sorts in the annals of computing in the modern era. The point here for quantum computers is to identify how capable a given quantum computer is compared to any of these historic machines.

Note: Some of the years may be off by a year or two or a matter of dispute due to differences between data of announcement, initial testing, and production deployment.

And then came the microprocessor

And then… came the microprocessors and everything changed, dramatically.

Although the 8-bit Intel 8080 and Motorola 6800 were introduced in 1974, and the 4-bit Intel 4004 had been introduced in 1971, and these chips saw some success in embedded and industrial control applications, it wasn’t until the introduction of the 16-bit Intel 8086 and Motorola 68000 in 1978 and 1979 that people began to take the microprocessor seriously as replacement for the older minicomputers, as well as to create workstations and personal computers, and later as 32-bit and then 64-bit microprocessors were introduced, for servers, replacements for mainframe computers, and even for supercomputers.


The question is how quickly useful applications will appear on quantum computers compared to the pace they appeared on traditional digital computers.

Some historical precedents:

It’s not that these particular applications have significance or would be relevant to quantum computing, but simply that quantum computers will need to prove their utility for applications of comparable complexity in terms of both code and data complexity and capacity.

Freelance Consultant