For many of us, the idea of living our lives without computers is more or less unthinkable. You couldn't be reading this now, and I couldn't have typed it - at least not to appear on screens.
For many of us, the cars we drive and phones we use all rely on computer technology. But computers are relatively recent stemming from Charles Babbage's ideas in the 19th century.
There's an entirely different question when it comes to computers - are they ever collectible, or are they as disposable as the box they came in once they've been rendered obsolete by the latest upgrade? Well, here are five examples of classic computers which remain coveted.
Gene Roddenberry's Apple Mac
One of the earliest Apple Mac computers, an Apple Mac Plus, was owned by a certain Gene Roddenberry, himself closely associated with science and technology albeit of a fantastical kind.
The Star Trek creator composed some of his best ideas on the clunky, beige box (which was thought to be rather stylish at the time) and it was sold for $8,260 at Profiles in History in 2009, smashing its $800-1,200 estimate.
This was probably at least as much to do with Star Trek fans as Apple followers. By comparison a 'Sickbay Desktop Computer' from Star Trek Voyager sold for $7,800 at Christie's in 2006, and that had no functionality whatsoever.
Apollo Guidance Computer
Needless to say, there are few more crucial occasions for relying on your technology than when you're floating through space.
Whilst the moonlanding missions relied on a startlingly limited amount of technology, each mission's guidance computer was an essential part of the mission, and so it's no surprise that an example sold for $50,000 in Heritage's 2009 space auction.
These days, elite cryptography is totally reliant on supercomputers crunching huge numbers in a way few understand. But the most famous code-making machines were much simpler - indeed largely mechanical, though computers nevertheless.
The coded messages handled by Enigma machines were thought to be unbreakable, but in a turning point for WWII British codebreakers including Alan Turing cracked top secret messages.
In September 2011, an Enigma machine smashed its £30,000-50,000 estimate to sell for £133,250 ($208,137) at Christie's.
Original Apple Mac
It seems hard to credit now, but Apple didn't look like it was going to be any kind of serious player when it first launched in 1976.
Just 200 units were offered out of a garage, with neither monitor nor keyboard included. The iPad was a long way off.
At Christie's last year (November 23, 2010) Italian collector Marco Boglione paid $210,000 to own one of the Apple-1 computers, complete with its original letter from Steve Jobs and a more recent note from his fellow Apple co-founder Steve Wozniak.
Analytical Engine parts
As we mentioned before, Charles Babbage is regarded as the father of modern computing, as he realised that certain calculating tasks could be done more efficiently and with fewer errors than when done by humans.
Although the machines he built were essentially mechanical, the architecture was quite similar to modern computers (the data and program memory were separated, operation was instruction based, etc).
Babbage was given money by the British government to develop his ideas, but never quite reached the conclusion he intended. Nevertheless, parts of his original uncompleted mechanisms are on display in the London Science Museum, as is half of Babbage's brain.
None of these impressive computing machines are ever likely to be available for sale. However, collectors wanting to get close to the workings of Babbage's brain will want to take a look at this handwritten note by the inventor and mathematician, which we currently have available.