As the IBM PC celebrates its 30th birthday one of the designers behind the iconic product reckons the traditional personal computer is dying.

Mark Dean, now chief technology officer for IBM Middle East and Africa, worked on the IBM 5150 – the first personal computer designed for individual use and one that helped the industry move away from the big centralised systems in use at the time.

August 12 marks the 30th anniversary of the 5150, which at the time was described by IBM as, "Designed for business, school and home, the easy-to-use system sells for as little as $1,565. It offers many advanced features and, with optional software, may use hundreds of popular application programs."

Now Dean says changing consumer behaviour means the role of the PC is changing. "When I helped design the PC, I didn’t think I’d live long enough to witness its decline. But, while PCs will continue to be much-used devices, they’re no longer at the leading edge of computing," Dean wrote. "They’re going the way of the vacuum tube, typewriter, vinyl records, CRT and incandescent light bulbs."

"PCs are being replaced at the centre of computing not by another type of device — though there’s plenty of excitement about smartphones and tablets — but by new ideas about the role that computing can play in progress. These days, it’s becoming clear that innovation flourishes best not on devices but in the social spaces between them, where people and ideas meet and interact. It is there that computing can have the most powerful impact on economy, society and people’s lives," he added.

Dean said he’s also moved on from a PC, and now uses a tablet as his main device. That is in some ways taking computing Back to the Future, as CBR has described. As more mobile devices such as smartphones, tablets and laptops are used at the office, workers are once again hooking up to a centralised system in a data centre.

Apple too has talked of the post-PC era where devices like its iPad 2 and other smartphones are dominant. "These are post-PC devices that need to be even easier to use than a PC. That need to be even more intuitive than a PC and where the software and the hardware and the applications need to intertwine in an even more seamless way than they do on a PC," is how Apple CEO Steve Jobs called it when unveiling the iPad 2.

Microsoft is not going as far as IBM or Apple. It can’t really, given how much it is reliant on revenue from its Windows operating system, an OS that has yet to make much of an impact in the mobile space.

Frank Shaw, corporate vice president, Corporate Communications at Microsoft wrote: "People sometimes ask me about what Microsoft thinks about the post-PC era (I prefer to think of it as the PC-plus era, since there will be 400 million PCs sold worldwide this coming year, but that’s semantics). It’s fairly straightforward. We continue to build great software, and our software’s value is expressed in the consumer and enterprise devices and services we deliver to our customers."