The Computer Tree

In 1961 the US Army drew the family tree of the electronic computer: ENIAC at the trunk, every machine built since hanging off a limb, rings at 1950, 1955 and 1960. This is that chart, transcribed, and grown one ring per decade to 2025: 542 machines and 614 links. Pick any machine and the tree draws its line back to the root.

How to read it

Every dot is a machine, a processor or a system, and its ring is the period it arrived in. The inner three rings are the 1961 chart's own; past them there is one ring per decade, and the outermost holds 2021 to 2025. Teal dots (207) were transcribed from the 1961 chart; orange dots (335) were added after it. A machine sits under its primary parent, the one the data names first. 80 machines have a second parent as well; switch on Cross-links to see them.

What it cannot carry

The 1961 links are shaky. The source was a low-resolution scan; most labels are legible, but many branch attachments in the dense middle are not, so 79% of the 1961 links are estimates, drawn dashed. The links added since are 89% firm. Read a dashed 1950s attachment as "same region of the chart", not as proven ancestry.

Some 1961 hubs are inflated: LOGISTICS and RASTAC show the most children on the chart partly because unreadable twigs were attached to the nearest legible branch. Past 1960 the tree follows major lineages, not every product, and Soviet and Eastern Bloc machines, most Japanese mainframes, SGI and MIPS, the Amiga and Atari, and early game consoles are among the gaps. Check a 1950s date or ancestry against a primary source before citing it.

The data

The dataset is a directed acyclic graph: every parent exists, there are no cycles, and no parent is dated more than a year after its child. Take it with you; the data card has the schema, the counts and how to add a decade.

The tree and its dataset were made for bradley.io, where the same page lives: bradley.io/projects/computer-tree