Convergence has been the Holy Grail for mobile phone makers, software and hardware partners, as well as consumers, for more than a decade.

And for the first time the rhetoric of companies like Nokia, Samsung and Motorola, who have boasted of putting a multimedia computer in your pocket, no longer seems far fetched.

"Converged devices are always with you and always connected," said Olli-Pekka Kallasvuo, Nokia chief executive at last week's Mobile World Congress in Barcelona.

Last year Nokia sold almost 200m camera phones and about 146m music phones, making it the world's biggest seller of digital cameras and MP3 players.

In the coming year the firm predicts it will sell 35 million GPS-enabled phones as personal navigation becomes the latest feature to be assimilated into the mobile phone.

Form and function

Nigel Clifford, chief executive of Symbian, said: "All of those single use devices - MP3 players, digital camera, GPS - are collapsing onto the phone."

"We are going past the point where this was a phone with a few other things," he said.

Symbian's operating system shipped on 188 million phones last year and a third of those came with GPS.

"We see mobile phones evolving into multi-functional devices that now support consumer electronics, multimedia entertainment and mobile professional enterprise applications; all converging," said Luis Pineda, from mobile phone chip firm Qualcomm.

Convergence is being driven by a combination of software, services and hardware.

The first phones powered by a chip running at 1Ghz will hit the market later this year, seven years after the first desktop chip broke the gigahertz barrier.

Qualcomm's 1Ghz Snapdragon chipset will debut inside a number of handsets, including some from Samsung and HTC

"It's a first in the industry for a wireless chipset," said Mr Pineda.

As well as raw horsepower Snapdragon also features a dedicated application processor, as well as the ability to handle 12 megapixel digital photos and up to 720p high definition video imaging.

Mr Clifford from Symbian said the mobile industry had to deliver multi-function devices which did not compromise.

He said: "When we look at what is collapsing on to these devices and people's expectations with their experiences on single-use specialized devices there is going to be rising expectations."

Chip shop

More than 90% of the world's mobile phones are powered by technology created by British firm Arm. It designs chip architectures that it licenses to semiconductors makers such as Qualcomm and Broadcom.

Ian Drew from Arm said future mobile phones demanded ever more processing power.

But building chips with greater processing was not a straightforward, he said.

"It needs to get into your pocket. And there's no fan. It needs to work for days rather than hours."

He added: "When you start adding multi media experiences- such as 3D graphics, video, and games - there are two ways to do that: you can get bigger and bigger processors or you have multi core where you can switch off a processor when you don't need it."

Arm is demonstrating a chip architecture, called Coretex A9, that will offer four cores, or processors, on a single chip.

Symbian has been working with Arm on future uses for multi-core mobile phones.

"You can use massive amounts of processing if you need it. But if you don't you can power down the cores that aren't required," said Mr Clifford.

Symmetrical Multi Processing will drive the next generation of applications on a phone, he added.

"Silicon vendors are looking very seriously at how they integrate SMP."

Mr Clifford added: "The future of the internet and computing applications is not going to be in the home or at the office; it's going to be mobile."

He said gaming would be the next feature to collapse into phones.

"That is one of the next single usage devices that will start feeling the pressure from the mobile device," he said.

3D graphics acceleration is becoming standard on many of today's mobile phones and specialists like Nvidia have joined the market.

Mr Clifford said today's most powerful mobile phones, such as Nokia's N96 and NTTDoCoMo's 905 series have the same power as a laptop from 2000.

Nvidia's APX 2500 chip has enough 3D graphics acceleration to handle Quake 3, a PC game from 1999, on a mobile phone.

Handset owners were also beginning to expect the same online experience they have on their desktop PCs on their mobile phones.

"Web 2.0, social networking and video sharing; that's a real driver of horsepower," said Mr Drew from Arm.

He added: "But you need to be able to get data in. The next generation of mobile phones need high performance radios - they will have high data rates that will enable this content to be streamed to you."

Symbian is working on technology called Freeway to give phones the ability to move seamlessly between wireless networks, like wi-fi and cell networks like 3G and 4G.

"We don't want people to feel the mobile web is a second class experience."

Bletchley Park is best known for the work done on cracking the German codes and helping to bring World War II to a close far sooner than might have happened without those code breakers.

But many believe Bletchley should be celebrated not just for what it ended but also for what it started - namely the computer age.

The pioneering machines at Bletchley were created to help codebreakers cope with the enormous volume of enciphered material the Allies managed to intercept.

The machine that arguably had the greatest influence in those early days of computing was Colossus - a re-built version of which now resides in the National Museum of Computing which is also on the Bletchley site.

Men and machine

The Enigma machines were used by the field units of the German Army, Navy and Airforce. But the communications between Hitler and his generals were protected by different machines: The Lorenz SZ40 and SZ42.

The German High Command used the Lorenz machine because it was so much faster than the Enigma, making it much easier to send large amounts of text.

"For about 500 words Enigma was reasonable but for a whole report it was hopeless," said Jack Copeland, professor of philosophy at the University of Canterbury in New Zealand, director of the Turing Archive and a man with a passionate interest in the Bletchley Park computers.

The Allies first picked up the stream of enciphered traffic, dubbed Tunny, in 1940. The importance of the material it contained soon became apparent.

Like Enigma, the Lorenz machines enciphered text by mixing it with characters generated by a series of pinwheels.

"We broke wheel patterns for a whole year before Colossus came in," said Captain Jerry Roberts, one of the codebreakers who deciphered Tunny traffic at Bletchley.

"Because of the rapid expansion in the use of Tunny, our efforts were no longer enough and we had to have the machines in to do a better job."

The man who made Colossus was Post Office engineer Tommy Flowers, who had instantly impressed Alan Turing when asked by the maverick mathematician to design a machine to help him in his war work.

But, said Capt Roberts, Flowers could not have built his machine without the astonishing work of Cambridge mathematician Bill Tutte.

"I remember seeing him staring into the middle distance and twiddling his pencil and I wondered if he was earning his corn," said Capt Roberts.

But it soon became apparent that he was.

"He figured out how the Lorenz machine worked without ever having seen one and he worked out the algorithm that broke the traffic on a day-to-day basis," said Capt Roberts.

"If there had not been Bill Tutte, there would not have been any need for Tommy Flowers," he said. "The computer would have happened later. Much later."

Valve trouble

Prof Copeland said Tommy Flowers faced scepticism from Bletchley Park staff and others that his idea for a high-speed computer employing thousands of valves would ever work.

"Flowers was very much swimming against the current as valves were only being used in small units," he said. "But the idea of using large numbers of valves reliably was Tommy Flowers' big thing. He'd experimented and knew how to control the parameters."

And work it did.

The close co-operation between the human translators and the machines meant that the Allies got a close look at the intimate thoughts of the German High Command.

Information gleaned from Tunny was passed to the Russians and was instrumental in helping it defeat the Germans at Kursk - widely seen as one of the turning points of WWII.

The greater legacy is the influence of Colossus on the origins of the computer age.

"Tommy Flowers was the key figure for everything that happened subsequently in British computers," said Prof Copeland.

After the war Bletchley veterans Alan Turing and Max Newman separately did more work on computers using the basic designs and plans seen in Colossus.

Turing worked on the Automatic Computing Engine for the British government and Newman helped to bring to life the Manchester Small Scale Experimental Machine - widely acknowledged as the first stored program computer.

The work that went into Colossus also shaped the thinking of others such as Maurice Wilkes, Freddie Williams, Tom Kilburn and many others - essentially the whole cast of characters from whom early British computing arose.

And the rest, as they say, is history

This article is from the BBC News website. © British Broadcasting Corporation