Previous Next

Aviator, launched with a great fanfare by Acornsoft in March, promises to be the high flier in the company's growing squadron of programs for the BBC. Billed as the world's first Spitfire flight simulator for a home computer, Aviator reproduces faithfully every aspect of the flight of the famous world war two aircraft, down to the screech of brakes on the tarmac and the slow response of the control column at low air speeds.

The author of Aviator, 30-year-old Geoffrey Crammond, knew nothing about Spitfires until he started writing the program and became involved with the BBC micro almost against his will.

A systems engineer with Marconi, Crammond counts electronics, especially allied to music and graphics, among his hobbies. "In 1981," he says, "I was toying with the idea of building a simulator in my spare time. Looking at the chips and hardware available at the time, I was thinking of buying a home computer to cannibalise it. Then I realised that most were as good off the shelf as anything I could build."

Crammond first set eyes on a BBC micro at a trade fair in August, 1981 and was so impressed with it that he sent an order next morning. It took six months for the machine to be delivered and during that time curiosity lured Crammond into an amusement arcade. He also began reading home computer magazines, whose small advertisements convinced him that there was a promising future in games software for home computers, all of which led to the idea for his first game, Super Invaders.

"I thought I would choose a well-known game for my first attempt," he says, "and Space Invaders seemed the obvious choice."

When the micro finally arrived in March, 1983, Crammond had to go back to basics, or rather assembler language. From his work with Marconi he was familiar with high-level Fortran but did not know Basic or machine code.

"It took me two months to learn to handle the machine and find how to move things round on the screen," Crammond recalls. It then took him another four months to write Super Invaders, which he sent to Acornsoft: out of the blue in the hope that the company would like and publish it.

"Luckily, I had written the game in mode 1, a more laborious process than using mode 7, but much better in terms of resolution and smoothness. Acornsoft already had a space invaders game written in mode 7 but accepted mine instead, with only a few minor modifications."

Slightly more forward planning went into the creation of Aviator. Crammond discussed his idea for a flight simulator with Acornsoft and a decision was made to base the program on the Spitfire rather than a modern passenger aircraft. "We chose the Spitfire because it is one of the most interesting aircraft to fly," says David Johnson-Davies, managing director of Acornsoft. "You can also perform stunts and aerobatics on it, unlike a DC10."

Crammond knew there were other flight simulators on the market but decided not to look at them so that he would remain free from other people's influences. "'Sometimes, just because someone has solved a problem in a certain way, you think that that is the only way to do it," he says. "I prefer to keep an open mind and try to find my own solutions."

Thus untrammelled by other people's concepts, Crammond researched and wrote the Aviator program single-handed, a mammoth task which took him nine months. Still employed at Marconi, he devoted every free evening, weekend and holiday to the program. "I was stuck occasionally," he recalls, "but I would just go to the library or talk to people to try to sort it out."

Much of the time Crammond spent on Aviator was devoted to research. Although during his first term at Bristol University he studied aeronautics, after that he switched to physics, the subject in which he eventually obtained his degree. For the program, he needed to know about the first principles of aerodynamics, as well as about aircraft instruments and the Spitfire.

Fortunately, he knew someone who had a wartime set of pilot's notes, the equivalent of a manual explaining to pilots the workings of the aircraft, an invaluable addition to the many other volumes he studied.

Crammond decided early to sacrifice colour to devote the full resources of the BBC micro to smooth, flicker-free graphics. "It was a compromise," he says, "one of the many you always have to make when writing a program."

For the same reason, the buildings and bridges over which the Spitfire flies in Aviator are drawn in simple line graphics. "Fitting in a database for the map of the terrain over which the Spitfire flies, the equations for its flight performance, as well as operational dashboard controls and 3-D graphics, stretched the machine to the full," says Crammond.

It is too early to tell whether Aviator will achieve the success Acornsoft is expecting for it but one man at least can vouch for the realism and authenticity of the program. He is Air Vice-marshal Sandy Johnstone who, standing beneath a Spitfire at the Royal Air Force Museum at Hendon, demonstrated what Aviator could do on the occasion of its press launch. Johnstone first flew a Spitfire in March, 1939 and went on to command a wing of Spitfires during the siege of Malta in 1942.

"The Spitfire was a most remarkable aircraft," Johnston says. "The first time I flew one was an experience rather similar to falling in love. Aviator certainly brings back the memories, right down to the sweaty palms. It even reproduces the bumpy take-oftf - we used to call it a 'whoopsy' take-off - which was so typical of the aircraft."

Acornsoft released Aviator primarily as a game but maintains that it also has educational value. The program is accompanied by a booklet which explains the aircraft control surfaces, the aerodynamic forces it would encounter, the instrument panels, some principles of navigation and piloting, and more. "Aviator has serious applications," says Johnson-Davies, '"'either in the classroom or for the flying instructor demonstrating the basics of small aircraft aviation."

Besides the booklet there is a map showing the terrain over which the simulator pilot is flying. Landmarks such as a lake, a bridge, and the town of Acornsville can be seen through the windscreen and appear on an even keel so long as you keep the aircraft under control. Otherwise they rush towards you, or tip dramatically sideways in a terrifying way.

For most people, piloting the aircraft successfully from 'whoopsy' take-off to landing is sufficient challenge but those with a real taste for bravado can also try to notch a score by flying through the streets of Acornsville or diving under the bridge. Extra points are awarded for performing the same feats upside down - even though Johnstone declined to attempt them.

Finally, if stunts should pall, there is a game called the Theme which involves saving the inhabitants of Acornsville from aliens who threaten to devour all the surrounding crops, sprout tentacles and take to the air to devastate the town.

Crammond attributes his fascination with aeroplanes to a time when during a school holiday he helped his father's building firm install partitions at a Rolls-Royce factory where Concorde parts were being built. "There it was in the next hangar," he says. "It was very exciting."

As for the art of writing such a complex program as Aviator, Crammond believes that the main requirements are confidence and determination. "You have to start with the idea that you will do it, not let us see if it can be done. You may not know how it will work out but you know that it will be done. That way, every hour you spend on a program, even if it is an hour where you are going back over something you have already done, will seem constructive and well-spent."

Born and raised in Somerset, Crammond now lives with his wife at Watford. Since completing Aviator, he has decided to leave his job with Marconi and devote himself full-time to programming. He has started work on one new game, about which he will say no more than it is 'made-up' rather than based on any other game, or indeed aircraft. Yet another game is in the pipeline but he will reveal even less about that.

Leaving his job with Marconi will mean sacrificing security for the uncertainties of a freelance existence but Crammond has no real fears about the future. With the experience of Super Invaders and Aviator behind him, he is confident of his ability to write good software. "Besides," he says, "even if no-one knows how long the games market will last, something else is bound to replace it."