The games people played: What am I bid for this Zork? John Windsor reports on the arrival of the Eighties in the London salerooms

Electronic games - vintage shoot-'em-ups and space invaders, modern role-playing adventures - have become collectable. The bulky, old-fashioned mainframe computer upon which the first game, Spacewar, was hacked out in 1962 is now a gamers' shrine in the Boston Computer Museum, Massachusetts - and computer games make their debut in the London salerooms on Thursday with a private collection of 1,100 at Christie's South Kensington at 2pm.

Offered as a single lot, this biggest-ever collection, amassed by Robin Matthews and Paul Rigby while writing The PC Games Bible, published last year, is estimated pounds 10,000-pounds 12,000. Bidding could go through the roof - or the floor. One cautious PC magazine editor reckons pounds 1,000 will be the limit.

The electronic-games industry, which now has an annual turnover approaching pounds 1bn, was sparked off by Steve 'Slug' Russell, a student member of Massachusetts Institute of Technology's High-Tech Model Railroad Club, who found while planning layouts that the binary switching of rail points could easily be translated into the language of MIT's now-famous PDP-1 mainframe. He and his friends then adapted as computer games E E 'Doc' Smith's pulp science-fiction novels such as The Lensman.

Their first game, a programmer's whim which never found its way into a cassette or floppy disk, was Spacewar. By the mid-Sixties it was a fixture on college mainframes throughout the US. Spacewar's graphics were B-movie-style rocket-ships each armed with 31 missiles and steered by toggle switches. It was copied as a coin-op arcade game, Asteroids. The nearest equivalent in the PC Games Bible collection is a reworking of Asteroids, the PC arcade game Blasteroids in which survivors of a space war confront a wicked alien, Mukor.

But the Penny Black of electronic-game collecting is none of the amateur arcade-style games with crude graphics and a few minutes' shoot-'em-up. Adventure, an amateur game illicitly developed on a Xerox research computer at Stanford University, gave its name to a new 'adventure' genre of computer games and was the forerunner of Zork, the first commercially successful computer game. It had no graphics or sound and no manual dexterity was called for. But its cryptic, text-only commands giving access to a Tolkienesque Great Underground Empire were so complex that when translated from mainframe into home-computer software they occupied three floppy discs. It took hour upon hour to decipher - and was an instant hit.

That was not until 1980. Zork - still available both second-hand and in an updated PC version - provoked a technological explosion in which developments in hardware and games software leap-frogged one another, leaving a wake of obsolescence that most people would call junk but which a few have found collectable. In London, at least two retailers, both called Computer Exchange, supply electronic- games buffs with second-hand treasures dating as far back as - well, the Eighties.

Much of the software is unplayable except on obsolete 'boxes' (gamers' slang for computers). Computer Exchange, in Notting Hill Gate, will sell you a Sinclair Spectrum computer for pounds 15-25 - when it can get hold of one. A BBC Model B is pounds 30, as is a Commodore 64, which can cost up to pounds 80 at other retailers. Some computer gamers own a dozen or more computers, to be sure of extracting the last spark of playability from each frail disk.

Collecting classic games is easy on the pocket. Even historic text- only games by Infocom, originators of Zork, seldom cost more than pounds 30 a disk over the counter. Small ads in the magazine Micro Computer Mart offer sought-after games at a standard pounds 10 each.

The trouble with computer software is that nobody can be sure how it will perform when beyond 10 years of age. Also, the frequent reissue of games at budget prices in formats compatible with the latest hardware makes nostalgic attachment to steam-age originals seem eccentric. Zork, for example, lives on in new PC software under the title Treasures of Infocom, price pounds 35.99. Ironically, collectors willing to part with up to pounds 30 for the original of a fondly remembered, grindingly slow, text-only game or to fill a gap in their collection are known in the trade as 'train-spotters'.

Those sceptical of the investment potential of the market might remember, however, that it took more than a generation before nostalgic 50-year-olds began to pay four-figure sums for the beloved Dinky Toys of their childhood.

The electronic-games collection of the future will reflect a battle for market share far fiercer than any inter-galactic combat on the computer screen. In 1985, when the trade thought that the shoot-'em-ups were dead and Amstrad launched its low-cost PC 1512 in anticipation of more sophisticated computer games, Sega and Nintendo's Game Boy and Super-Mario hit the scene with old-fashioned, arcade-style games in a completely new format - hand- held push-button consoles containing cartridges with memory chips, plugged into ordinary television screens. They became a craze, doubling turnover annually towards last year's UK peak of pounds 700-pounds 750m (compared with pounds 100m-pounds 150m for PC games).

But while the console-game market appears to have peaked, the PC-game market is picking itself up. The IBM PC revolution of the Eighties and the dipping of PC prices to below pounds 1,000 have been main factors. Nowadays, while local newspapers carry dozens of for-sale ads for unwanted gaming consoles, Level One, HMV's electronic-game sales floor in Oxford Street, is thronged not with children but with men in business suits in their twenties and thirties, playing PC games with highly focused sound, 256 colours and full-motion graphics, costing pounds 45 or more.

According to David Terrill, HMV's UK marketing director, this age group is the leading edge of the PC-games market. As an indicator of their sophisticated taste and buying power, he cited the launch in October of the PC game Frontier, originally Elite, a taxing inter-galactic adventure which spawned amateur fanzines when first launched in slow, low-powered, home-computer format eight years ago. Updated for PC at pounds 39.99, it sold an initial European run of 100,000 within days.

The true state of the market will be revealed next month when the Jurassic Park of the console market, Mortal Kombat, comes out on PC. In September it grossed pounds 50m at pounds 49.99 a copy after a poster campaign that scared parents stiff. Its charm for both parents and collectors is that, like any other title, it will be lucky to last six months on the shelves before becoming a cert for the bin - or the archive.

Nintendo's bustling, bash'-em-up Mario, soon to flaunt himself on PC screens, is also struggling to avoid becoming a collectors' piece. Has he the brainpower to exploit fully the latest technological advance - the 650-megabyte CD-ROM game disk with 800 times the capacity of a cartridge and 11 times the capacity of a PC floppy, which can take programmers two years to fill and the average game-player a lifetime to thwart the dinosaurs and reach the crock of gold?

The PC Games Bible by Robin Matthews and Paul Rigby, Sigma Press pounds 12.95. Level One, HMV, 150 Oxford Street, London W1 (071-631 3423). Computer Exchange, 65 Notting Hill Gate, W11 (071-243 1863). Computer Exchange, 143 Whitfield Street, London W1 (071-916 3110).

(Photograph omitted)