Whether you realise it or not, the games consoles that are the top-selling 'toys' this year are computers. But they are simple, old-fashioned and inflexible machines. You can plug in a special cartridge and play games on them, but that is all.
That is certainly not the case with an office machine, however. With its flexibility, speed, vastly larger data storage and significantly superior picture quality, a PC can do things that designers for games consoles can only dream about.
'The ultimate games machine has to be a very powerful PC,' says Paul Moodie, marketing director of the games company Microprose. 'The down side is the cost and size of the machine. Getting into the game may be more difficult, because you may have to fight through DOS commands. A Sega Mega Drive sells for pounds 125 retail, less than half the price of a PC.'
The market for games breaks down into about a third for console machines, such as the Nintendo Entertainment System and the Sega Mega Drive, a third for the hand-held, such as the Nintendo Game Boy and the Sega Game Gear, and a third for the floppy market, Mr Moodie says. This is divided mainly between the Atari ST, Commodore Amiga and the IBM PC compatible market.
One thing in favour of PC games is that they are normally cheaper than the Nintendo and Sega cartridges. These cost pounds 40- pounds 50, compared with about pounds 30 for PC software. Mr Moodie says that the cartridges are expensive because of their complicated electronics and the licensing fees that Nintendo and Sega charge.
While there are no licences for PC software, the machines' flexibility means customers expect more sophisticated games. As a result development costs are much higher. 'It can cost pounds 200,000 to develop a game for a computer system. It takes nowhere near the time or money for a cartridge game as they are relatively simple and straightforward,' Mr Moodie says.
But the market for the 'floppy' sector is changing. 'A year ago we were developing products for the Amiga and converting them to the PC. Now it is the other way round. In the US, Commodore and Atari have died a death - it is nearly all PC-based now. The European market is moving that way as well,' Mr Moodie says.
The good news for more mature computer games players is that the PC excels at the types of game that adults like to play.
Different computer games appeal to different age groups. Adults tend to appreciate simulations and strategy games more than the 'shoot-em-up' action variety that teenagers prefer.
I am living proof of this. Recently, I have spent too much time playing Sim City for Windows, Railroad Tycoon and Civilisation. Playing this last game has kept me up till 2am when I had an important meeting the following morning. I have also ignored favourite television programmes and neglected friends.
In Civilisation, the player's task is to build a civilisation from scratch. As you discover the world around you and establish cities at appropriate places, your population grows. At the same time you must devote a certain amount of effort to researching new technologies, finance the maintenance of improvements to your city and provide sufficient luxuries to keep your people happy and prevent civil unrest.
Each technological advance brings with it new skills and weapons as well as the ability to develop still more complex technologies.
But there is more. You are not alone in your world. There are up to seven other civilisations expanding at various speeds. These are placed randomly on to the planet and develop unseen until you encounter them as you explore. But seen or not, at each turn the computer works out where each of the empires would expand, fights wars between the unseen civilisations and builds and destroys cities. With excellent graphics, the computing tasks involved in all of this is pretty impressive. All in all, it is a computing tour de force.
But Civilisation illustrates a point that comes up repeatedly with strategy games. You have to make choices in which one thing influences another. For example, in Sim City, you have to develop and manage a city, dealing with problems of crime, pollution, fires and so forth. But when funds are running low, you soon discover that the obvious solution, putting the taxes up sharply, has disastrous consequences, with much of your population deserting you. This means less people to tax and reduced revenue.
Such games teach the players, albeit in a simplified way, about the choices any society has to make, and it is not surprising that Sim City has found its way into many schools in the United States as an educational tool.
Other types of games that appeal to adults include sporting competitions, with golf and motor sports particular favourites. Animated role-playing games are also popular. These are mostly set in ancient times and require the player to find a magic potion, save the city or rescue a defenceless princess. These tend to attract a younger audience but there are a couple of honourable exceptions. The Leisure Suit Larry games have a wonderfully unredeeming plot line, with the player cast as an ineffectual, sleazy little character who is always trying to pick up women. While it has a 'Warning - Parental Discretion Advised' sticker, it is more schoolboy humour than porn and is deliberately corny. (It is worth noting that Microprose, which makes Railroad Tycoon and Civilisation, has discovered that more than 98 per cent of its customers are male. The company knew the market was male-dominated, but was astonished at the figure.)
However, if you decide to take the plunge and buy a PC game this Christmas, your problems could be just beginning - finding the correct software can be difficult.
Dixons sells Nintendo and Sega games cartridges in all its 357 stores, but PC software is available in only 170 outlets, and these may stock a limited number of games.
Of W H Smith's 450 stores, 320 carry cartridges, 290 carry software for the Amiga and Atari and only 10 carry software for the PC. Boots carries cartridges in 220 stores, Atari and Amiga software in 200, but PC software in only 40.
Specialist retailers are a more reliable source. Virgin stocks PC software in all its Megastores and games shops, but with only 48 outlets, you may have trouble finding one near you. The obvious place to look is in a local PC shop, although the range of software it stocks is likely to be limited and expensive. However, the situation is likely to improve quite dramatically next year. Boots is reviewing its distribution in the new year. 'The IBM PC is the thing for the future - that is the way the American market has gone,' a company spokesman says.
'The Atari is on its last legs, and we will move to PC and Amiga only,' Andrew Stafford, product manager for computer games at W H Smith, says. 'There is now a much greater awareness of what you can do with a PC. However, both Sega and Nintendo are putting so much behind their products that everything else is being drowned out at the moment.'
Dave King, games product manager at Virgin Retail, says that people are 'moving up' from their Atari or Amiga to a PC, and there is evidence that people who use PCs at work are buying games to play on them. He believes that these 'executive users' represent a vast untapped market, but that they will be hard to reach.
So, before Christmas, why not nip out and buy yourself F15 Strike Eagle, or Chopper Wars or Nuclear Holocaust or Build a Better World or some other equally improbable piece of fantasy? Then when sweet little Crispin or darling Anton wants to show you how he can zap Robocop, why not show him how you can fly upside down over New York, take over the world, or destroy a planet?
Ah, the Christmas spirit still lives.