Doug Engelbart invented the computer mouse in 1963-64 as part of an experiment to find better ways to point and click on a display screen. This was fashioned downstairs in the shop at SRI, with the casing carved out of wood, with just 1 button - that's all there was room for. Subsequent model of the mouse very soon had three buttons; Engelbart would have gone for more buttons but there was only room for three of the then-available micro-switches.

The patent he got for the mouse 1963-64 was called: "X-Y Position Indicator for a Display System". Why didn't he get rich from the mouse? It didn't achieve widespread use until the patent expired.

The first mouse

.au 11.127 khz 16 bits mono with µLaw 2;1 compression.

Originally recorded on an Apple Macintosh PowerBook using a SONY ECM-T145 condenser microphone and Adobe Premiere audio/video editing software. The original recording was saved as a QuickTime file at 22 mhz, 16 bits with no compression.
Due to Doug's characteristically low voice it was then imported into a Premiere project where the volume was raised in the project timeline three times (no filter) and saved as a QuickTime movie.
The document was then finally imported into Apple's QuickTime Player and exported as .au at 11.127 khz, 16 bits mono with µLaw 2;1 compression resulting in the version playing here.