© Armonk/IBM/dpa

On August 12, 1981, IBM presented the IBM PC 5150 in New York, which had been developed in the greatest secrecy. Technology purists were disappointed. The chip was not powerful enough for a reasonable graphics display. Microsoft's DOS was criticized as a weak software architecture. However, the 1-2-3 calculation program for the IBM PC was able to run more complex calculation models than the Apple II and drove the competition out of offices. In the USA, the cheapest version cost...