Built 1964 · about seventeen dollars in parts
The Mother of All Demos — 02 / 07
The Mouse
A block of wood, two knife-edge wheels set at right angles, and room on top for one button.
01
Two wheels at right angles
Bill English built it in 1964 from Engelbart's sketch. Two knife-edge wheels under a shaped pine shell, each reporting one axis as the block is pushed, on a machined aluminium bracket.
The cable came out of the back at first, where a tail belongs. It moved to the front because it caught under the wrist.
02
Why it won
A year after it was built it beat every other pointing device SRI tested, including a knee-operated lever and a light pen. Nothing has displaced it since.
“We just started calling it a mouse,” Engelbart said later, “and nobody remembers who did.”
03
Where the prototypes are
The surviving prototype and its replicas are in museum vitrines — the Computer History Museum in Mountain View and the Science Museum Group's collection, whose two studio plates are the clearest pictures of it that exist.
The half the industry took
The mouse went everywhere. The other half of the interface did not.