I think the very first time I used a computer was when I was about 9 years old. It was when I went out on a food parcel delivery mission with my school. We stopped by the office of one of the other kids dads, and played this moon landing game (Lunar Lander, I think it was) on the office computer. God knows what kind of computer it was; this was the pre-PC era, well and truly.

It was 1979, and the PC as we know it still hadnt been invented. The aim was to land your capsule on the moon without crashing, and it was all done by typing text at a command prompt on the screen. No graphics. Text only. I was totally hooked. Mum and Dad were hassled into buying me a handheld electronic game which played a knock-off version of Space Invaders, the daddy of all arcade games.

Slightly less than 3 decades later, I'm typing this on a PC with two graphics cards entirely devoted to video processing. For playing games on, of course; we reached the level needed to run a usable office desktop by the early 1990s. I typed up my PhD on a Mac Classic (which also had some games on it, but by this time such things had become commonplace. In the early 80s arcade video game machines had started appearing at the local leisure center; there was nothing more alluring.

Except the big kids just hogged them. And if you managed to have a go on one (Space Invaders, Asteroids, Galaxian, and after that Pac Man were the big things) then you found that your 10p or 20p or whatever it was didn't usually buy you very much time in the hot seat. Then came the home video gaming revolution, in the form of game consoles, and then actual computers, like Atari, and then the Spectrum, or the Amiga or the BBC, that you would connect to a TV as a display device. I remember being so desperate to play on my friends Atari computer game console that I would turn up at his house at an indecent hour on a Saturday morning to make him play it with me.

After all, I was growing up in a household without a telly, which even by the late 1970s was unusual. These days it would make you a freak. In fact, I still watch very little TV. But I'm probably more 'screen-dependent', shall we say, than many square-eyed 1970s telly addicts. If I'm at home, I'm rarely far from my computer. Of course, computer use and TV use differ; right now I'm typing, trying to put together a piece of coherent writing, and that's not something you do while watching TV.

Perhaps the real problem is that computers have aggregated our activities in a way which has meant they have become less distinct; I can go from writing serious prose to chatting to friends to reading the news to playing a game and I need never move from this chair. And to the external observer I'm not even doing anything different, I'm just sitting at a keyboard. For hours. Something tells me this can't be healthy.

Nevertheless, I do love computer games. After that first wave of what are now regarded (with some justification) as the 'arcade classics', I can remember a few that stuck in my mind from the mid-80s. There was a 2-D scrolling flying game (Defender I think) that launched a whole host of imitators (like a Harrier game for the Spectrum?). There were text-based fantasy adventures with pixellated images. They were utterly basic, and I loved them all. But I particularly loved fast-paced action games, and in the late 80s the amiga still seemed to have the best ones.

There was speedball, a 5-a-side top-down game by the Bitmap Brothers who produced a few great titles in those days. It was clearly inspired by the film Rollerball, a violent future sport, and the aim was to get the ball into the other team's goal by any means necessary. There were all sorts of objects on the field that you could pick up - what are now known as 'power-ups' that temporarily boost your abilities - and cash with which to build your team.

Part of the genius of this game was that it had leagues and a management element so that you could empathise with the fortunes of Brutal Deluxe, or whatever your team was called. It tapped into the fact that there are no stories so powerful as the ones you tell yourself. Only this can explain how the spreadsheet-based world of football management games with no on-pitch action to them became so popular.

Myself, I never went wild about management simulations, or sims, to use another common piece of twenty-first century jargon. I liked the action gaming side of things. I started playing computer football games in 1995 or so, first on the PC, then for a while on the playstation, and then on the PC again. I still play Fifa 2007 now, and the subtlety is extraordinary; every game is different, just like real football.

But when I was playing a lot of speedball, the PC still had to make a dramatic entrance on the scene. I can remember a student at Oxford in the late 80s actually having a PC (with colour monitor, even) in his room, and that was unusual. He had some great flight simulator game I was rubbish at and loved. But really, in the early 90s gaming continued to be dominated by consoles; I have the impression that Nintendo particular assumed the crown Atari had worn in the 70s and early 80s.

It wasn't really until the birth of the first person shooter genre around 1995 that the PC came into its own as a games machine. Until that time other devices could do the same or better. Quake, and the like, were something new. They were fast paced, and I remember that after playing for 20 minutes or so I would get really severe motion sickness. It doesn't usually happen to me these days, I think games are written with that problem in mind more; it's something to do with how the on screen camera moves and affects the brain. Half-Life 2 was the first one in a while that got me like that, and it was nowhere near as bad as original Quake. I remember how tense and excited I used to get in Quake, which probably also helps to explain why the motion sickness was so bad. After a decade or so of those sorts of games, I'm a lot cooler on the trigger. But there was no way that you could deny the immersiveness of this new gaming point of view. Here you were, in the game for the first time.

These days many games let you toggle between a third and first person view, and I have to admit that sometimes I like to see my character onscreen as well as see through their eyes. But whichever perspective is chosen, the power of computer gaming as a new storytelling medium was becoming obvious to a much wider audience by the mid-90s. Games like Quake were at the opposite end of the spectrum (pardon the pun) from something like Myst, a so-called 'point and click' adventure in which an image was displayed on the screen, elements of which would respond to mouse clicks. This was all about leisurely puzzle-solving, not blowing chunks off zombies. I had a flatmate who played it a lot, and it was beautifully drawn. I remember after I finished my PhD, I basically did nothing for about a month but play Fifa soccer, X-Wing, Doom, and X-Com on his PC.

I didn't get my first PC til 1999, I think, and the first think I wanted to do with it was play games on it. What a shame it ran Windows 98, possibly the most unstable operating system Microsoft have ever devised. The fact I had to keep reinstalling it (OK, I probably also didn't really know what I was doing back then) sure used to eat into my playing time. But gradually I got on top of using a PC to play games on. To anyone who just wants to play games these days I'd probably recommend an X-Box or a Playstation, but PC games usually have the advantage of being much more modifiable by their users and develop loyal fanbases who will write all sorts of software add-ons; that's one upside of the complexity of the PC as a gaming platform.

Another is of course is that there's a huge array of games; I've never stopped playing computer footy, and hopefully never will, as the games get better every year. But there are fantasy games that take me back to my youth spent playing pen and paper role playing games, action games more action packed than most thrillers, driving games, simulations (despite what I said above about simulations in general, which I like the idea more than the reality of, the first Sims game was actually one I played a lot of when that first came out for the PC), lots of other sports games, some fantastic first person shooter games (like Half Life 2, which I finished); I've spent quite a few happy years enjoying them.

Another is the ever improving graphics; the 'eye candy' as they call it. One of the definite disadvantages of a console, if you must have the latest and greatest in visuals, is that you can't upgrade it. That hardware won't change for the life of the platform, though developers can squeeze more out of the system as they adapt to it, so it's said. But the PC is a continuous upgrade; video card companies change their product line every 6 months, and the jumps in performance are often massive. Photorealism isn't an end in itself, although it's close to being achieved; it's much more about how the scenes are drawn by the artists. The best games are directed in the same way as films, so that they realise an artistic vision.

If that sounds pretentious, well, then you probably haven't played your way through many PC games lately. One of the best over the last few years was Mafia, which was an extraordinarily well-written, scripted, and directed thriller set in the 1930s. Living the life of someone who moves from accidental numbers man to made guy made for a classic story, and the player was taken through it brilliantly.

If you didn't play it, then you really missed out. I believe in the value of computer games, contra Boris Johnson, who made a recent ill-informed attack on them. Boris is a good bloke, but has sometimes been known to get it wrong, and he's done so again here. Of course too much of anything is a bad thing; but computer games are a quintessentially modern form of entertainment, and they definitely form part of life's rich tapestry.