40 years ago, Popular Electronics revealed the Altair 8800. The machine was developed by Edward Roberts of MITS. Kits were offered at 397$, and fully assembled machines at 498$, beating current contenders by a large margin.
Roberts had anticipated to sell a few hundred kits throughout the following year. Instead, he had 1000 orders on his desk by February 1975, and by August had sold over 5000 units. The microcomputer craze had started.