Who were the PC giants of the past? Apple and IBM led the way with retail sales, followed by Compaq and Hewlett-Packard. Dell and Gateway dominated direct sales. Packard Bell and eMachines gained big market shares with really cheap PCs.
Who will be the PC giants of the future? Dell, of course, but most of the others will be drawn from a clutch including Toshiba, Sony, NEC, Fujitsu, Sharp, Acer and Legend.
It does not take a brain the size of a planet to spot that the first lot are all US firms, and most of them made their money from desktop PCs and servers. Most of the second group are Japanese, and most of them have done much better out of notebooks and ultralites. The exceptions are Acer, which is based in Taiwan, and Legend, which is a major player in China.
The notebook form factor plays to Japanese strengths in consumer electronics design and marketing. Also, unlike US manufacturers, they can source vast quantities of memory chips, small hard drives and LCD screens locally. Although IBM Thinkpads are American, the technology was driven by IBM Japan, and Apple - 40% of its sales are now notebooks - has lots made in Taiwan.
Apart from Dell, most of the US manufacturers are in retreat. Compaq has been taken over by Hewlett-Packard. Gateway and Apple have seen their sales slump. IBM is no longer the 800-pound gorilla of the desktop PC market. Packard Bell is owned by NEC. The Texas Instruments notebook brand belongs to Acer.
And it is going to get worse. Today, according to market figures from analyst firms Gartner and IDC, the market for desktop PCs is flat at best. Only the notebook business is showing real growth - a situation that has recently made Toshiba one of the world's top-five PC supplier s.
This growth looks likely to continue, thanks partly to the rapid take-up of Wi-Fi wireless networking. Microsoft is promoting wireless Tablet PCs, while Intel has included Wi-Fi connectivity as part of the Centrino chipset for "thin and light" notebooks and Tablet PCs.
Indeed, having got rich from desktop PCs, the dynamic duo of Microsoft and Intel is now targeting non-PC mobiles. These include Pocket PCs and smartphones - Microsoft Windows CE running on Intel XScale processors - and portable video players, where the Japanese should do even better.
In the 1970s, the focus of computing went west from Armonk. It could go west again and move to Japan.
Jack Schofield is computer editor of the Guardian