One thing this is leaving out is that IBM existed, and was very successful, long before mainframes. The company has existed since the 1880s for christ's sake. A

One thing this is leaving out is that IBM existed, and was very successful, long before mainframes. The company has existed since the 1880s for christ's sake. Additionally, during the mainframe era it had a number of other successful products, like the selectric typewriter. The history of IBM (http://en.wikipedia.org/wiki/History_of_IBM http://en.wikipedia.org/wiki/History_of_IBM) is pretty damn long. If you pick your dates right it's easy to find trends, but the real world is much more complex. HP, for instance, has taken a long, meandering path to where it is. It doesn't fit on a simple chart with simple graphics.